Publications by authors named "Brad J Schoenfeld"

182 Publications

Muscle Fiber Type Transitions with Exercise Training: Shifting Perspectives.

Sports (Basel) 2021 Sep 10;9(9). Epub 2021 Sep 10.

Health Sciences Department, CUNY Lehman College, Bronx, NY 10468, USA.

Human muscle fibers are generally classified by myosin heavy chain (MHC) isoforms characterized by slow to fast contractile speeds. Type I, or slow-twitch fibers, are seen in high abundance in elite endurance athletes, such as long-distance runners and cyclists. Alternatively, fast-twitch IIa and IIx fibers are abundant in elite power athletes, such as weightlifters and sprinters. While cross-sectional comparisons have shown marked differences between athletes, longitudinal data have not clearly converged on patterns in fiber type shifts over time, particularly between slow and fast fibers. However, not all fiber type identification techniques are created equal and, thus, may limit interpretation. Hybrid fibers, which express more than one MHC type (I/IIa, IIa/IIx, I/IIa/IIx), may make up a significant proportion of fibers. The measurement of the distribution of fibers would necessitate the ability to identify hybrid fibers, which is best done through single fiber analysis. Current evidence using the most appropriate techniques suggests a clear ability of fibers to shift between hybrid and pure fibers as well as between slow and fast fiber types. The context and extent to which this occurs, along with the limitations of current evidence, are discussed herein.
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http://dx.doi.org/10.3390/sports9090127DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8473039PMC
September 2021

Drop-Set Training Elicits Differential Increases in Non-Uniform Hypertrophy of the Quadriceps in Leg Extension Exercise.

Sports (Basel) 2021 Aug 29;9(9). Epub 2021 Aug 29.

Department of Health Sciences, Lehman College, Bronx, NY 10468, USA.

The study aimed to compare the effects of drop set resistance training (RT) versus traditional RT on markers of maximal muscle strength and regional hypertrophy of the quadriceps femoris. Sixteen recreationally active young men had one leg randomly assigned to the drop-set method (DS) and the other to training in a traditional manner (TRAD). Participants performed unilateral seated leg extensions using a periodized approach for eight weeks. Rectus femoris (RF) and vastus lateralis (VL) muscle thickness (MT), estimated one repetition maximum (RM) in the unilateral knee extension, and peak and average isokinetic knee extension torque at 60°/s angular velocity were measured pre- and post-study. Both conditions increased muscle thickness of the RF and VL from pre- to post-intervention. DS showed statistically greater increases in the RF at 30% and 50% of muscle length, whereas no MT differences were detected at 70% muscle length nor at any aspect of the VL. Both DS and TRAD increased estimated one RM from pre- to post-study (+34.6% versus +32.0%, respectively) with no between-condition differences noted. Both conditions showed similar increases in peak torque (DS: +21.7%; TRAD: +22.5%) and average torque (DS: +23.6%; TRAD: +22.5%) from pre- to post-study. Our findings indicate a potential benefit of the drop-set method for inducing non-uniform hypertrophic gains in the RF muscle pursuant to leg extension training. The strategy did not promote an advantage in improving hypertrophy of the VL, nor in strength-related measures, compared to traditional training.
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http://dx.doi.org/10.3390/sports9090119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8473065PMC
August 2021

The Effect of Whole Egg Intake on Muscle Mass: Are the Yolk and Its Nutrients Important?

Int J Sport Nutr Exerc Metab 2021 Sep 9:1-8. Epub 2021 Sep 9.

Laboratory of Nutrition, Exercise and Health (LaNES), School of Medicine, Federal University of Uberlandia (UFU), Uberlandia, Minas Gerais,Brazil.

Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g., microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.
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http://dx.doi.org/10.1123/ijsnem.2021-0086DOI Listing
September 2021

International Society of Sports Nutrition position stand: sodium bicarbonate and exercise performance.

J Int Soc Sports Nutr 2021 Sep 9;18(1):61. Epub 2021 Sep 9.

Performance & Physique Enhancement Laboratory, University of South Florida, Tampa, FL, 33612, USA.

Based on a comprehensive review and critical analysis of the literature regarding the effects of sodium bicarbonate supplementation on exercise performance, conducted by experts in the field and selected members of the International Society of Sports Nutrition (ISSN), the following conclusions represent the official Position of the Society: 1. Supplementation with sodium bicarbonate (doses from 0.2 to 0.5 g/kg) improves performance in muscular endurance activities, various combat sports, including boxing, judo, karate, taekwondo, and wrestling, and in high-intensity cycling, running, swimming, and rowing. The ergogenic effects of sodium bicarbonate are mostly established for exercise tasks of high-intensity that last between 30 s and 12 min. 2. Sodium bicarbonate improves performance in single- and multiple-bout exercise. 3. Sodium bicarbonate improves exercise performance in both men and women. 4. For single-dose supplementation protocols, 0.2 g/kg of sodium bicarbonate seems to be the minimum dose required to experience improvements in exercise performance. The optimal dose of sodium bicarbonate dose for ergogenic effects seems to be 0.3 g/kg. Higher doses (e.g., 0.4 or 0.5 g/kg) may not be required in single-dose supplementation protocols, because they do not provide additional benefits (compared with 0.3 g/kg) and are associated with a higher incidence and severity of adverse side-effects. 5. For single-dose supplementation protocols, the recommended timing of sodium bicarbonate ingestion is between 60 and 180 min before exercise or competition. 6. Multiple-day protocols of sodium bicarbonate supplementation can be effective in improving exercise performance. The duration of these protocols is generally between 3 and 7 days before the exercise test, and a total sodium bicarbonate dose of 0.4 or 0.5 g/kg per day produces ergogenic effects. The total daily dose is commonly divided into smaller doses, ingested at multiple points throughout the day (e.g., 0.1 to 0.2 g/kg of sodium bicarbonate consumed at breakfast, lunch, and dinner). The benefit of multiple-day protocols is that they could help reduce the risk of sodium bicarbonate-induced side-effects on the day of competition. 7. Long-term use of sodium bicarbonate (e.g., before every exercise training session) may enhance training adaptations, such as increased time to fatigue and power output. 8. The most common side-effects of sodium bicarbonate supplementation are bloating, nausea, vomiting, and abdominal pain. The incidence and severity of side-effects vary between and within individuals, but it is generally low. Nonetheless, these side-effects following sodium bicarbonate supplementation may negatively impact exercise performance. Ingesting sodium bicarbonate (i) in smaller doses (e.g., 0.2 g/kg or 0.3 g/kg), (ii) around 180 min before exercise or adjusting the timing according to individual responses to side-effects, (iii) alongside a high-carbohydrate meal, and (iv) in enteric-coated capsules are possible strategies to minimize the likelihood and severity of these side-effects. 9. Combining sodium bicarbonate with creatine or beta-alanine may produce additive effects on exercise performance. It is unclear whether combining sodium bicarbonate with caffeine or nitrates produces additive benefits. 10. Sodium bicarbonate improves exercise performance primarily due to a range of its physiological effects. Still, a portion of the ergogenic effect of sodium bicarbonate seems to be placebo-driven.
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http://dx.doi.org/10.1186/s12970-021-00458-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8427947PMC
September 2021

Does Varying Repetition Tempo in a Single-Joint Lower Body Exercise Augment Muscle Size and Strength in Resistance-Trained Men?

J Strength Cond Res 2021 Jan 22. Epub 2021 Jan 22.

Department of Health Sciences and Human Performance, The University of Tampa, Tampa, Florida.

Pearson, J, Wadhi, T, Barakat, C, Aube, D, Schoenfeld, BJ, Andersen, JC, Barroso, R, Ugrinowitsch, C, and De Souza, EO. Does varying repetition tempo in a single-joint lower body exercise augment muscle size and strength in resistance-trained men? J Strength Cond Res XX(X): 000-000, 2021-This study compared the effects of FAST and SLOW eccentric repetition tempo in a single exercise volume-matched intervention on muscle thickness (MT) and strength in resistance-trained men. Using a within-subject design, 13 subjects had each leg randomly assigned to SLOW (1-0-3) or FAST (1-0-1) repetition tempo. Subjects underwent an 8-week strength-training (ST) intervention performed twice weekly. Unilateral leg-extension one repetition-maximum (1RM) and anterior thigh MT at the proximal (MTP) and distal (MTD) portions were assessed via ultrasound imaging at baseline and after 8 weeks of RT. Rating of perceived exertion (RPE) assessments of the training sessions (i.e., 16 per leg) were averaged for further analysis. Both legs similarly increased MTP (estimated differences: FAST: 0.24 cm, 3.6%; SLOW: 0.20 cm, 3.1%). However, for MTD, analysis of covariance analysis showed a leg effect (p = 0.02) in which absolute pre-to-post change was greater in FAST compared with SLOW (estimated differences: FAST 0.23 cm, 5.5%; SLOW: 0.13 cm, 2.2%). For 1RM, both legs similarly increased maximum strength (estimated differences: FAST: 9.1 kg, 17.0%; SLOW: 10.4 kg, 22.1%, p <= 0.0001). The SLOW group had a higher RPE than FAST (8.59 vs. 7.98, p = 0.002). Despite differences in RPE, our results indicate that both repetition tempos produced similar muscular adaptations. However, they also suggest that the FAST tempo may provide a small hypertrophic advantage at the distal quadriceps. From a practical standpoint, strength and conditioning professionals may implement a FAST tempo at least in one single-joint exercise during an 8-week training period to enhance regional hypertrophic adaptations in trained individuals.
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http://dx.doi.org/10.1519/JSC.0000000000003953DOI Listing
January 2021

Effects of Time-Restricted Feeding on Supramaximal Exercise Performance and Body Composition: A Randomized and Counterbalanced Crossover Study in Healthy Men.

Int J Environ Res Public Health 2021 07 6;18(14). Epub 2021 Jul 6.

Laboratório de Função Neuromuscular, Faculdade de Motricidade Humana, Universidade de Lisboa, Estrada da Costa, 1499-002 Cruz Quebrada-Dafundo, Portugal.

Using a crossover design, we explored the effects of both short- and long-term time-restricted feeding (TRF) vs. regular diet on Wingate (WnT) performance and body composition in well-trained young men. Twelve healthy male physical education students were included (age: 22.4 ± 2.8 years, height: 174.0 ± 7.1 cm, body mass: 73.6 ± 9.5 kg, body mass index: 24.2 ± 2.0 kg/m). The order of dieting was randomized and counterbalanced, and all participants served as their own controls. TRF was limited to an 8-h eating window and non-TRF involved a customary meal pattern. Participants performed WnT tests and body composition scans at baseline, post-one and post-four weeks of the assigned diet. Before testing, participants were asked to fill out a dietary record over four consecutive days and were instructed to continue their habitual training throughout the study. Energy intake and macronutrient distribution were similar at baseline in both conditions. WnT mean power and total work output increased post-four weeks of TRF. Both conditions were similarly effective in increasing fat-free mass after four weeks of intervention. However, there was no correlation between change in fat-free mass and WnT mean power after TRF. TRF did not elicit any changes in WnT performance or body composition one week post-intervention. Thus, long-term TRF can be used in combination with regular training to improve supramaximal exercise performance in well-trained men.
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http://dx.doi.org/10.3390/ijerph18147227DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8303210PMC
July 2021

Effects of Two vs. Four Weekly Campus Board Training Sessions on Bouldering Performance and Climbing-Specific Tests in Advanced and Elite Climbers.

J Sports Sci Med 2021 09 25;20(3):438-447. Epub 2021 May 25.

Department of sport, food and natural sciences, Western Norway University of Applied Sciences, Sogndal, Norway.

This study examined the effects of two or four weekly campus board training sessions among highly accomplished lead climbers. Sixteen advanced-to-elite climbers were randomly allocated to two (TG2), or four weekly campus board training sessions (TG4), or a control group (CG). All groups continued their normal climbing routines. Pre- and post-intervention measures included bouldering performance, maximal isometric pull-up strength using a shallow rung and a large hold (jug), and maximal reach and moves to failure. Rate of force development (RFD; absolute and 100ms) was calculated in the rung condition. TG4 improved maximal force in the jug condition (effect size (ES) = 0.40, p = 0.043), and absolute RFD more than CG (ES = 2.92, p = 0.025), whereas TG2 improved bouldering performance (ES = 2.59, p = 0.016) and maximal moves to failure on the campus board more than CG (ES = 1.65, p = 0.008). No differences between the training groups were found (p = 0.107-1.000). When merging the training groups, the training improved strength in the rung condition (ES = 0.87, p = 0.002), bouldering performance (ES = 2.37, p = 0.006), maximal reach (ES = 1.66, p = 0.006) and moves to failure (ES = 1.43, p = 0.040) more than CG. In conclusion, a five-week campus board training-block is sufficient for improving climbing-specific attributes among advanced-to-elite climbers. Sessions should be divided over four days to improve RFD or divided over two days to improve bouldering performance, compared to regular climbing training.
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http://dx.doi.org/10.52082/jssm.2021.438DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8256519PMC
September 2021

Volume Reduction: Which Dose is Sufficient to Retain Resistance Training Adaptations in Older Women?

Int J Sports Med 2021 Jul 13. Epub 2021 Jul 13.

Metabolism, Nutrition, and Exercise Laboratory, Physical Education and Sport Center, State University of Londrina, Londrina, PR, Brazil.

We compared the effects of different resistance training (RT) volume reduction strategies on muscular strength and lean soft-tissue (LST) in older women. Fifty-seven physically independent women (>60 years) performed a 20-week pre-conditioning phase of a standardized whole-body RT program (eight exercises, three sets, 8-12 repetitions, three sessions a week), and were then randomly assigned to one of the following conditions: reduced volume for a single set (RV1, n=20) or two sets (RV2, n=19), or maintained volume of three sets (MV, n=18) for 8 weeks (specific training phase). Muscular strength in the chest press, leg extension, and preacher curl exercises was determined by one-repetition maximum tests. A dual-energy X-ray absorptiometry device was used to estimate LST. An increase in muscular strength (16.3-32.1%) and LST (3.2-7.9%) was observed after the pre-conditioning phase. There was an increase in chest press for all groups (9.4-16.7%) after the specific training phase. In contrast, only MV increased significantly in the leg extension (4.4%). No between-group differences were revealed for LST in the specific training phase. Our results suggest that reduced RT volume from three to one set per exercise for 8 weeks seems sufficient to retain neuromuscular adaptations in older women.
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http://dx.doi.org/10.1055/a-1502-6361DOI Listing
July 2021

Effects of a 12-Week Suspension versus Traditional Resistance Training Program on Body Composition, Bioimpedance Vector Patterns, and Handgrip Strength in Older Men: A Randomized Controlled Trial.

Nutrients 2021 Jun 30;13(7). Epub 2021 Jun 30.

Department of Biomedical and Neuromotor Sciences, University of Bologna, 40126 Bologna, Italy.

This investigation aimed to compare the effects of suspension training versus traditional resistance exercise using a combination of bands and bodyweight on body composition, bioimpedance vector patterns, and handgrip strength in older men. Thirty-six older men (age 67.4 ± 5.1 years, BMI 27.1 ± 3.3 kg/m) were randomly allocated into suspension training ( = 12), traditional training ( = 13), or non-exercise ( = 11) groups over a 12-week study period. Body composition was assessed using conventional bioelectrical impedance analysis and classic and specific bioelectric impedance vector analysis, and handgrip strength was measured with a dynamometer. Results showed a significant ( < 0.05) group by time interaction for fat mass, fat-free mass, total body water, skeletal muscle index, classic and specific bioelectrical resistance, classic bioelectrical reactance, phase angle, and dominant handgrip strength. Classic and specific vector displacements from baseline to post 12 weeks for the three groups were observed. Handgrip strength increased in the suspension training group ( < 0.01, ES: 1.50), remained stable in the traditional training group, and decreased in the control group ( < 0.01, ES: -0.86). Although bodyweight and elastic band training helps to prevent a decline in muscle mass and handgrip strength, suspension training proved more effective in counteracting the effects of aging in older men under the specific conditions studied.
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http://dx.doi.org/10.3390/nu13072267DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8308438PMC
June 2021

Personalized, Evidence-Informed Training Plans and Exercise Prescriptions for Performance, Fitness and Health.

Sports Med 2021 09 18;51(9):1805-1813. Epub 2021 Jun 18.

Department of Health Sciences, Lehman College, Bronx, NY, USA.

A training plan, or an exercise prescription, is the point where we translate sport and exercise science into practice. As in medicine, good practice requires writing a training plan or prescribing an exercise programme based on the best current scientific evidence. A key issue, however, is that a training plan or exercise prescription is typically a mix of many interacting interventions (e.g. exercises and nutritional recommendations) that additionally change over time due to periodisation or tapering. Thus, it is virtually impossible to base a complex long-term training plan fully on scientific evidence. We, therefore, speak of evidence-informed training plans and exercise prescriptions to highlight that only some of the underlying decisions are made using an evidence-based decision approach. Another challenge is that the adaptation to a given, e.g. endurance or resistance training programme is often highly variable. Until biomarkers for trainability are identified, we must therefore continue to test athletes, clients, or patients, and monitor training variables via a training log to determine whether an individual sufficiently responds to a training intervention or else re-plan. Based on these ideas, we propose a subjective, pragmatic six-step approach that details how to write a training plan or exercise prescription that is partially based on scientific evidence. Finally, we advocate an athlete, client and patient-centered approach whereby an individual's needs and abilities are the main consideration behind all decision-making. This implies that sometimes the most effective form of training is eschewed if the athlete, client or patient has other wishes.
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http://dx.doi.org/10.1007/s40279-021-01495-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8363526PMC
September 2021

No Time to Lift? Designing Time-Efficient Training Programs for Strength and Hypertrophy: A Narrative Review.

Sports Med 2021 10 14;51(10):2079-2095. Epub 2021 Jun 14.

Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.

Lack of time is among the more commonly reported barriers for abstention from exercise programs. The aim of this review was to determine how strength training can be most effectively carried out in a time-efficient manner by critically evaluating research on acute training variables, advanced training techniques, and the need for warm-up and stretching. When programming strength training for optimum time-efficiency we recommend prioritizing bilateral, multi-joint exercises that include full dynamic movements (i.e. both eccentric and concentric muscle actions), and to perform a minimum of one leg pressing exercise (e.g. squats), one upper-body pulling exercise (e.g. pull-up) and one upper-body pushing exercise (e.g. bench press). Exercises can be performed with machines and/or free weights based on training goals, availability, and personal preferences. Weekly training volume is more important than training frequency and we recommend performing a minimum of 4 weekly sets per muscle group using a 6-15 RM loading range (15-40 repetitions can be used if training is performed to volitional failure). Advanced training techniques, such as supersets, drop sets and rest-pause training roughly halves training time compared to traditional training, while maintaining training volume. However, these methods are probably better at inducing hypertrophy than muscular strength, and more research is needed on longitudinal training effects. Finally, we advise restricting the warm-up to exercise-specific warm-ups, and only prioritize stretching if the goal of training is to increase flexibility. This review shows how acute training variables can be manipulated, and how specific training techniques can be used to optimize the training response: time ratio in regard to improvements in strength and hypertrophy.
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http://dx.doi.org/10.1007/s40279-021-01490-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8449772PMC
October 2021

Peak week recommendations for bodybuilders: an evidence based approach.

BMC Sports Sci Med Rehabil 2021 Jun 13;13(1):68. Epub 2021 Jun 13.

Health Sciences Department, Lehman College, NY, Bronx, USA.

Bodybuilding is a competitive endeavor where a combination of muscle size, symmetry, "conditioning" (low body fat levels), and stage presentation are judged. Success in bodybuilding requires that competitors achieve their peak physique during the day of competition. To this end, competitors have been reported to employ various peaking interventions during the final days leading to competition. Commonly reported peaking strategies include altering exercise and nutritional regimens, including manipulation of macronutrient, water, and electrolyte intake, as well as consumption of various dietary supplements. The primary goals for these interventions are to maximize muscle glycogen content, minimize subcutaneous water, and reduce the risk abdominal bloating to bring about a more aesthetically pleasing physique. Unfortunately, there is a dearth of evidence to support the commonly reported practices employed by bodybuilders during peak week. Hence, the purpose of this article is to critically review the current literature as to the scientific support for pre-contest peaking protocols most commonly employed by bodybuilders and provide evidence-based recommendations as safe and effective strategies on the topic.
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http://dx.doi.org/10.1186/s13102-021-00296-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8201693PMC
June 2021

Carbohydrate refeed does not modify GVT-performance following energy restriction in bodybuilders.

Clin Nutr ESPEN 2021 06 20;43:308-316. Epub 2021 Apr 20.

Post-Graduation Program on Physical Education, Catholic University of Brasilia, Q.S. 07, Lote 01, EPTC - Bloco G, 71966-700, Taguatinga, Federal District, Brazil. Electronic address:

Bodybuilding is a sport in which competitors' physiques are judged on their muscular size, symmetry, and leanness, as displayed in a number of different poses. In the pre-competitive period, bodybuilders attempt to reduce body fat stores as much as possible while maintaining fat-free mass (FFM). This is achieved via a sustained negative energy balance, generally induced by a combination of decreased energy intake and increased energy expenditure. This study aimed to assess the ability of bodybuilders to resist fatigue during resistance exercise based German Volume Training (GVT), as well as the affective response after carbohydrate refeed following four weeks of moderate or severe energy restriction. Eleven male bodybuilders (28.4 ± 2.3 years old) with experience in competitions were randomized into two groups: Moderate Energy Restriction (MER; n = 6) or Severe Energy Restriction (SER; n = 5). On the 2nd day (during energy restriction) and 7th day (during refeed) of the fourth week, both groups completed two leg press protocols involving the GVT method. After the first and last workout protocol subjects were assessed for muscle soreness using the visual-analog scale (VAS), rating of perceived exertion (RPE), affective response, lactate, and creatine kinase. Anthropometric analysis indicated that a reduction of 3.7 and 3.2% in body mass corresponded to a loss of 16.0 and 17.6% of fat mass for the MER and SER groups, respectively, with both groups maintaining FFM. Blood CK and VAS values were reduced only in SER. Our results suggest that a carbohydrate refeed may help to attenuate the perception of muscle soreness and maintain exercise performance, especially when severe energy restriction is combined with an intense training protocol such as GVT.
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http://dx.doi.org/10.1016/j.clnesp.2021.03.034DOI Listing
June 2021

Effects of a low-carbohydrate ketogenic diet on health parameters in resistance-trained women.

Eur J Appl Physiol 2021 Aug 18;121(8):2349-2359. Epub 2021 May 18.

Physical Education and Sports, Faculty of Medicine, University of Málaga, Málaga, Spain.

Purpose: The aim of this study was to evaluate the effect of a ketogenic diet on blood pressure, visceral adipose tissue (VAT), bone mineral content (BMC), and bone mineral density (BMD) in trained women.

Methods: Twenty-one resistance-trained women performed an 8-week resistance training program after a 3-week familiarization phase. Participants were randomly assigned to a non-ketogenic diet (n = 11, NKD) or ketogenic diet (n = 10, KD) group. Health parameters were measured before and after the nutritional intervention. Blood pressure was measured using a digital automatic monitor, while VAT, BMC, and BMD changes were measured by dual-energy X-ray absorptiometry.

Results: There was a significant reduction in systolic blood pressure in KD (mean ± SD [IC 95%], P value, Hedges' g; - 6.3 ± 6.0 [- 10.5, - 2.0] mmHg, P = 0.009, g = - 0.81) but not in NKD (- 0.4 ± 8.9 [- 6.8, 6.0] mmHg, P = 0.890, g = - 0.04). The results on VAT showed no changes in both groups. The KD showed a small favorable effect on BMD (0.02 ± 0.02 [0.01, 0.03] g·cm, P = 0.014, g = 0.19) while NKD did not show significant changes (0.00 ± 0.02 [- 0.02, 0.02] g·cm, P = 0.886, g = 0.01). No differences in group or in the time × group interaction were found in any of the variables.

Conclusions: Consuming a low-carbohydrate high-fat KD in conjunction with a resistance training program might help to promote the improvement of health-related markers in resistance-trained women. Long-term studies are required to evaluate the superiority of a KD in comparison to a traditional diet.
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http://dx.doi.org/10.1007/s00421-021-04707-3DOI Listing
August 2021

Partial range of motion training elicits favorable improvements in muscular adaptations when carried out at long muscle lengths.

Eur J Sport Sci 2021 May 23:1-11. Epub 2021 May 23.

Weight Training Laboratory, School of Physical Education, Physiotherapy and Occupational Therapy, Federal University of Minas Gerais, Belo Horizonte, Brazil.

The study compared changes in strength and regional muscle hypertrophy between different ranges of motion (ROM) in the knee extension exercise. Forty-five untrained women were randomized to either a control group or to perform the exercise in one of the following 4 groups (0°=extended knee): Full ROM (FULL: 100°-30° of knee flexion); Initial Partial ROM (INITIAL: 100°-65°); Final Partial ROM (FINAL: 65°-30°); Varied ROM (VAR: daily alternation between the ROM of INITIAL and FINAL). Pre- and post-training assessments included one repetition maximum (1RM) testing in the ROM corresponding to the initial, final and full ROM, and measurement of cross-sectional areas of the rectus femoris and vastus lateralis muscles at 40%, 50%, 60% and 70% of femur length in regard to regional muscle hypertrophy. Results showed that the INITIAL group presented a greater relative increase than all groups at 70%, and at 50% and 60% the increases were greater than FINAL, FULL, and non-training control (CON) groups. Moreover, FINAL group presented similar changes compared to the CON group at 60% and 70%. In regard to 1RM, FINAL and INITIAL groups presented greater relative increases at the ROM trained, and no group showed greater increases than VAR or INITIAL, regardless the ROM tested. In conclusion, partial ROM training in the initial phase of the knee extension exercise promoted greater relative hypertrophy in certain muscle regions than training in other ROM configurations, and no group promoted a greater 1RM increase than VAR group, which showed similar 1RM increases in the different ROMs tested.
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http://dx.doi.org/10.1080/17461391.2021.1927199DOI Listing
May 2021

Hormonal and Inflammatory Responses to Hypertrophy-Oriented Resistance Training at Acute Moderate Altitude.

Int J Environ Res Public Health 2021 04 16;18(8). Epub 2021 Apr 16.

Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, 18011 Granada, Spain.

This study investigated the effect of a traditional hypertrophy-oriented resistance training (R) session at acute terrestrial hypoxia on inflammatory, hormonal, and the expression of miR-378 responses associated with muscular gains. In a counterbalanced fashion, 13 resistance trained males completed a hypertrophic R session at both moderate-altitude (H; 2320 m asl) and under normoxic conditions (N; <700 m asl). Venous blood samples were taken before and throughout the 30 min post-exercise period for determination of cytokines (IL6, IL10, TNFα), hormones (growth hormone [GH], cortisol [C], testosterone), and miR-378. Both exercise conditions stimulated GH and C release, while miR-378, testosterone, and inflammatory responses remained near basal conditions. At H, the R session produced a moderate to large but nonsignificant increase in the absolute peak values of the studied cytokines. miR-378 revealed a moderate association with GH (r = 0.65; = 0.026 and r = -0.59; = 0.051 in N and H, respectively) and C (r = 0.61; = 0.035 and r = 0.75; = 0.005 in N and H, respectively). The results suggest that a R session at H does not differentially affect the hormonal, inflammatory, and miR-378 responses compared to N. However, the standardized mean difference detected values in the cytokines suggest an intensification of the inflammatory response in H that should be further investigated.
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http://dx.doi.org/10.3390/ijerph18084233DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8072638PMC
April 2021

The Impact of Coronavirus (COVID-19) Related Public-Health Measures on Training Behaviours of Individuals Previously Participating in Resistance Training: A Cross-Sectional Survey Study.

Sports Med 2021 07 19;51(7):1561-1580. Epub 2021 Apr 19.

Solent University, Southampton, UK.

Introduction: Understanding the impact of lockdown upon resistance training (RT), and how people adapted their RT behaviours, has implications for strategies to maintain engagement in similar positive health behaviours. Further, doing so will provide a baseline for investigation of the long-term effects of these public health measures upon behaviours and perceptions, and facilitate future follow-up study.

Objectives: To determine how the onset of coronavirus (COVID-19), and associated 'lockdown', affected RT behaviours, in addition to motivation, perceived effectiveness, enjoyment, and intent to continue, in those who regularly performed RT prior to the pandemic.

Methods: We conducted an observational, cross-sectional study using online surveys in multiple languages (English, Danish, French, German, Italian, Portuguese, Slovakian, Swedish, and Japanese) distributed across social media platforms and through authors' professional and personal networks. Adults (n = 5389; median age = 31 years [interquartile range (IQR) = 25, 38]), previously engaged in RT prior to lockdown (median prior RT experience = 7 years [IQR = 4, 12]) participated. Outcomes were self-reported RT behaviours including: continuation of RT during lockdown, location of RT, purchase of specific equipment for RT, method of training, full-body or split routine, types of training, repetition ranges, exercise number, set volumes (per exercise and muscle group), weekly frequency of training, perception of effort, whether training was planned/recorded, time of day, and training goals. Secondary outcomes included motivation, perceived effectiveness, enjoyment, and intent to continue RT.

Results: A majority of individuals (82.8%) maintained participation in RT during-lockdown. Marginal probabilities from generalised linear models and generalised estimating equations for RT behaviours were largely similar from pre- to during-lockdown. There was reduced probability of training in privately owned gyms (~ 59% to ~ 7%) and increased probability of training at home (~ 18% to ~ 89%); greater probability of training using a full-body routine (~ 38% to ~ 51%); reduced probability of resistance machines (~ 66% to ~ 13%) and free weight use (~ 96% to ~ 81%), and increased probability of bodyweight training (~ 62% to ~ 82%); reduced probability of moderate repetition ranges (~ 62-82% to ~ 55-66%) and greater probability of higher repetition ranges (~ 27% to ~ 49%); and moderate reduction in the perception of effort experienced during-training (r = 0.31). Further, individuals were slightly less likely to plan or record training during lockdown and many changed their training goals. Additionally, perceived effectiveness, enjoyment, and likelihood of continuing current training were all lower during-lockdown.

Conclusions: Those engaged in RT prior to lockdown these behaviours with only slight adaptations in both location and types of training performed. However, people employed less effort, had lower motivation, and perceived training as less effective and enjoyable, reporting their likelihood of continuing current training was similar or lower than pre-lockdown. These results have implications for strategies to maintain engagement in positive health behaviours such as RT during-restrictive pandemic-related public health measures. PRE-REGISTRATION: https://osf.io/qcmpf .

Preprint: The preprint version of this work is available on SportRχiv: https://osf.io/preprints/sportrxiv/b8s7e/ .
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http://dx.doi.org/10.1007/s40279-021-01438-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8054258PMC
July 2021

Can conditions of skeletal muscle loss be improved by combining exercise with anabolic-androgenic steroids? A systematic review and meta-analysis of testosterone-based interventions.

Rev Endocr Metab Disord 2021 06 30;22(2):161-178. Epub 2021 Mar 30.

Medical School, Federal University of Fronteira Sul, SC 484 - Km 02, Chapecó, Santa Catarina, Brazil.

Sarcopenia, cachexia, and atrophy due to inactivity and disease states are characterized by a loss of skeletal muscle mass, often accompanied by reduced levels of anabolic hormones (e.g. testosterone). These conditions are associated with an increase in mortality, hospitalization and worsening in quality of life. Both physical exercise (EX) and anabolic-androgenic steroid (AAS) administration can improve the prognosis of patients as they increase physical functionality. However, there is a gap in the literature as to the impact of these therapies on the gains in strength and muscle mass and their implications for patient safety. Accordingly, we performed a random-effects meta-analysis to elucidate the effects of AAS and/or EX interventions on lean body mass (LBM) and muscle strength in conditions involving muscle loss. A systematic search for relevant clinical trials was conducted in MEDLINE, EMBASE, SCOPUS, Web of Science, and SPORTDiscus. Comparisons included AAS vs. Control, EX vs. Control, AAS vs. EX, AAS + EX vs. AAS and AAS + EX vs. EX. A total of 1114 individuals were analyzed. AAS increased LBM (effect size [ES]: 0.46; 95% CI: 0.25, 0.68, P = 0.00) and muscle strength (ES: 0.31; 95% CI: 0.08, 0.53, P = 0.01) when compared to a control group. EX promoted an increase in muscular strength (ES: 0.89; 95% CI: 0.53, 1.25, P = 0.00), with no effect on LBM when compared to the control group (ES: 0.15; 95% CI: -0.07, 0.38, P = 0.17). AAS did not demonstrate statistically significant differences when compared to EX for LBM and muscle strength. The combination of EX + AAS promoted a greater increase in LBM and muscular strength when compared to AAS or EX in isolation. Qualitatively, AAS administration had relatively few side effects. Significant heterogeneity was found in some analyses, which may be explained by the use of different AAS types and EX protocols. Our findings suggest that AAS administration in cachectic and sarcopenic conditions may be a viable interventional strategy to enhance muscle function when exercise is not a possible approach. Moreover, combining AAS with exercise may enhance positive outcomes in this population.
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http://dx.doi.org/10.1007/s11154-021-09634-4DOI Listing
June 2021

Isolated Leucine and Branched-Chain Amino Acid Supplementation for Enhancing Muscular Strength and Hypertrophy: A Narrative Review.

Int J Sport Nutr Exerc Metab 2021 Mar 18;31(3):292-301. Epub 2021 Mar 18.

CUNY Lehman College.

Branched-chain amino acids (BCAA) are one of the most popular sports supplements, marketed under the premise that they enhance muscular adaptations. Despite their prevalent consumption among athletes and the general public, the efficacy of BCAA has been an ongoing source of controversy in the sports nutrition field. Early support for BCAA supplementation was derived from extrapolation of mechanistic data on their role in muscle protein metabolism. Of the three BCAA, leucine has received the most attention because of its ability to stimulate the initial acute anabolic response. However, a substantial body of both acute and longitudinal research has now accumulated on the topic, affording the ability to scrutinize the effects of BCAA and leucine from a practical standpoint. This article aims to critically review the current literature and draw evidence-based conclusions about the putative benefits of BCAA or leucine supplementation on muscle strength and hypertrophy as well as illuminate gaps in the literature that warrant future study.
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http://dx.doi.org/10.1123/ijsnem.2020-0356DOI Listing
March 2021

Effects of Power-Oriented Resistance Training During an Altitude Camp on Strength and Technical Performance of Elite Judokas.

Front Physiol 2021 18;12:606191. Epub 2021 Feb 18.

Department of Physical Education and Sport, University of Granada, Granada, Spain.

This study investigated the effect of a 3-week power-oriented resistance training program performed at moderate altitude on leg power output variables in a countermovement jump, a related judo technique () and the relationship between them. Twenty-four elite male judokas were randomly assigned to a hypobaric hypoxia or normoxia group. Mechanical outputs from an incremental loaded countermovement jump test and the kinematic variables transferred to a dummy during an test (time to execution and movement accelerations) were assessed before, after, 1 and 2 weeks after training. Results indicated an increase in explosive leg capacity both at moderate altitude (2320 m.a.s.l.) and sea level. The hypoxia group showed additional benefits when compared to normoxia group for peak velocities with different percentages of the body weight, maximal theoretical velocity and jump height after the training period, and these additional benefits in jump height were maintained 2 weeks after training. The hypoxia group achieved a higher peak performance in peak velocity and jump height than normoxia group (peak velocity: 8.8 vs. 5.6%, jump height: 8.2 vs. 1.4%, respectively) and was achieved earlier in hypoxia (after training) than in normoxia (1 week after training). However, there was a detrimental effect for the hypoxia group on the times of execution and acceleration of the compared to the normoxia group. These results suggest that altitude training may induce faster and greater improvements in explosive leg extension capacity. Specific technique-oriented training should be included at altitude to prevent technique impairment.
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http://dx.doi.org/10.3389/fphys.2021.606191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7930574PMC
February 2021

Loading Recommendations for Muscle Strength, Hypertrophy, and Local Endurance: A Re-Examination of the Repetition Continuum.

Sports (Basel) 2021 Feb 22;9(2). Epub 2021 Feb 22.

Department of Health Sciences, CUNY Lehman College, Bronx, NY 10468, USA.

Loading recommendations for resistance training are typically prescribed along what has come to be known as the "repetition continuum", which proposes that the number of repetitions performed at a given magnitude of load will result in specific adaptations. Specifically, the theory postulates that heavy load training optimizes increases maximal strength, moderate load training optimizes increases muscle hypertrophy, and low-load training optimizes increases local muscular endurance. However, despite the widespread acceptance of this theory, current research fails to support some of its underlying presumptions. Based on the emerging evidence, we propose a new paradigm whereby muscular adaptations can be obtained, and in some cases optimized, across a wide spectrum of loading zones. The nuances and implications of this paradigm are discussed herein.
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http://dx.doi.org/10.3390/sports9020032DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7927075PMC
February 2021

Effects of resistance training performed to repetition failure or non-failure on muscular strength and hypertrophy: A systematic review and meta-analysis.

J Sport Health Sci 2021 Jan 23. Epub 2021 Jan 23.

Fitness Academy, Zagreb 10000, Croatia; Faculty of Kinesiology, University of Zagreb, Zagreb 10000, Croatia.

Purpose: We aimed to perform a systematic review and meta-analysis of the effects of training to muscle failure or non-failure on muscular strength and hypertrophy.

Methods: Meta-analyses of effect sizes (ESs) explored the effects of training to failure vs. non-failure on strength and hypertrophy. Subgroup meta-analyses explored potential moderating effects of variables such as training status (trained vs. untrained), training volume (volume equated vs. volume non-equated), body region (upper vs. lower), exercise selection (multi- vs. single-joint exercises (only for strength)), and study design (independent vs. dependent groups).

Results: Fifteen studies were included in the review. All studies included young adults as participants. Meta-analysis indicated no significant difference between the training conditions for muscular strength (ES = -0.09; 95% confidence interval (95%CI): -0.22 to 0.05) and for hypertrophy (ES = 0.22; 95%CI: -0.11 to 0.55). Subgroup analyses that stratified the studies according to body region, exercise selection, or study design showed no significant differences between training conditions. In studies that did not equate training volume between the groups, the analysis showed significant favoring of non-failure training on strength gains (ES = -0.32; 95%CI: -0.57 to -0.07). In the subgroup analysis for resistance-trained individuals, the analysis showed a significant effect of training to failure for muscle hypertrophy (ES = 0.15; 95%CI: 0.03-0.26).

Conclusion: Training to muscle failure does not seem to be required for gains in strength and muscle size. However, training in this manner does not seem to have detrimental effects on these adaptations, either. More studies should be conducted among older adults and highly trained individuals to improve the generalizability of these findings.
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http://dx.doi.org/10.1016/j.jshs.2021.01.007DOI Listing
January 2021

International society of sports nutrition position stand: caffeine and exercise performance.

J Int Soc Sports Nutr 2021 Jan 2;18(1). Epub 2021 Jan 2.

Performance & Physique Enhancement Laboratory, University of South Florida, Tampa, FL, 33612, USA.

Following critical evaluation of the available literature to date, The International Society of Sports Nutrition (ISSN) position regarding caffeine intake is as follows: 1. Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance in many but not all studies. Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions. 2. Aerobic endurance appears to be the form of exercise with the most consistent moderate-to-large benefits from caffeine use, although the magnitude of its effects differs between individuals. 3. Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3-6 mg/kg body mass. Minimal effective doses of caffeine currently remain unclear but they may be as low as 2 mg/kg body mass. Very high doses of caffeine (e.g. 9 mg/kg) are associated with a high incidence of side-effects and do not seem to be required to elicit an ergogenic effect. 4. The most commonly used timing of caffeine supplementation is 60 min pre-exercise. Optimal timing of caffeine ingestion likely depends on the source of caffeine. For example, as compared to caffeine capsules, caffeine chewing gums may require a shorter waiting time from consumption to the start of the exercise session. 5. Caffeine appears to improve physical performance in both trained and untrained individuals. 6. Inter-individual differences in sport and exercise performance as well as adverse effects on sleep or feelings of anxiety following caffeine ingestion may be attributed to genetic variation associated with caffeine metabolism, and physical and psychological response. Other factors such as habitual caffeine intake also may play a role in between-individual response variation. 7. Caffeine has been shown to be ergogenic for cognitive function, including attention and vigilance, in most individuals. 8. Caffeine may improve cognitive and physical performance in some individuals under conditions of sleep deprivation. 9. The use of caffeine in conjunction with endurance exercise in the heat and at altitude is well supported when dosages range from 3 to 6 mg/kg and 4-6 mg/kg, respectively. 10. Alternative sources of caffeine such as caffeinated chewing gum, mouth rinses, energy gels and chews have been shown to improve performance, primarily in aerobic exercise. 11. Energy drinks and pre-workout supplements containing caffeine have been demonstrated to enhance both anaerobic and aerobic performance.
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http://dx.doi.org/10.1186/s12970-020-00383-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7777221PMC
January 2021

Human chorionic gonadotropin treatment: a viable option for management of secondary hypogonadism and male infertility.

Expert Rev Endocrinol Metab 2021 Jan 21;16(1):1-8. Epub 2020 Dec 21.

Graduate School of Medicine, Department of Urology, Juntendo University , Tokyo, Japan.

: Low testosterone and its symptoms is a condition affecting many males with severe repercussions on health. Testosterone affects metabolism, bones, joints, and ligaments, the cardiovascular system, liver, sexual functions, muscle mass, and the nervous system. Nowadays, due to recent research showing the benefits of testosterone replacement therapy, this treatment is gaining in popularity among aging men. However, testosterone replacement can increase the risk of infertility. : Human chorionic gonadotropin (HCG) is used in the treatment of male infertility due to its luteinizing hormone (LH)-like action triggering testosterone and sperm production. Due to these positive effects on testosterone production, HCG has also been used to treat secondary hypogonadism. In this review, based on a literature review for the years 1977-2020 via Google Scholar, we summarize the current research on HCG as treatment for patients suffering from low testosterone and provide an overview of the pros and contras for HCG therapy as compared to testosterone replacement therapy for the treatment of secondary hypogonadism. : The testosterone and sperm production triggering effects of HCG without the side effects on fertility seen in testosterone replacement therapy make HCG therapy a prime candidate for patients suffering from secondary hypogonadism.
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http://dx.doi.org/10.1080/17446651.2021.1863783DOI Listing
January 2021

Resistance Exercise Intensity Does Not Influence Neurotrophic Factors Response in Equated Volume Schemes.

J Hum Kinet 2020 Aug 31;74:227-236. Epub 2020 Aug 31.

School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, Brazil.

The aim of the present study was to evaluate the effects of 2 different intensities of resistance training (RT) bouts, performed with the equated total load lifted (TLL), on the acute responses of neurotrophic factors (NFs) (brain-derived neurotrophic factor [BDNF]; and nerve growth factor [NGF]), as well as on metabolic (lactate concentration) and hormonal (salivary cortisol concentration) responses. Thirty participants (males, 22.8 ± 2.3 years old, 177 ± 6.8 cm, 75.5 ± 7.9 kg, n = 15; and females, 22.2 ± 1.7 years, 163.7 ± 6.5 cm, 57 ± 7.6 kg, n = 15) performed 2 separate acute RT bouts with one week between trials. One bout consisted of 4 sets of 5 submaximal repetitions at 70% of 1RM and the other of 4 sets of 10 submaximal repetitions at 35% of 1RM for each exercise. Both RT bouts were conducted using the bench press and squat exercises. The TLL in each bout (determined by sets x repetitions x load [kg]) was equated. Serum BDNF, serum NGF, salivary cortisol, and blood lactate concentration were determined pre- and post-RT. No significant pre- to post-exercise increase in neurotrophic factors (p > 0.05; BDNF; effect size = 0.46 and NGF; effect size = 0.48) was observed for either of the RT bouts. A similar increase in blood lactate concentration was observed pre- to post-exercise for both RT bouts (p < 0.05). Cortisol increased similarly for both RT bouts, when compared to the resting day condition (p < 0.05). In conclusion, the results suggest that, despite differences in RT schemes, a similar acute neurotrophic, metabolic and hormonal response was observed when the TLL is equated.
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http://dx.doi.org/10.2478/hukin-2020-0030DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7706651PMC
August 2020

Caffeine Ingestion Enhances Repetition Velocity in Resistance Exercise: A Randomized, Crossover, Double-Blind Study Involving Control and Placebo Conditions.

J Hum Kinet 2020 Aug 31;74:177-183. Epub 2020 Aug 31.

Faculty of Kinesiology, University of Zagreb, Zagreb, Croatia.

We aimed to examine the effects of placebo and caffeine compared to a control condition on mean velocity in the bench press exercise. Twenty-five resistance-trained men participated in this randomized, crossover, double-blind study. The participants performed the bench press with loads of 50%, 75%, and 90% of one-repetition maximum (1RM), after no supplementation (i.e., control), and after ingesting caffeine (6 mg/kg), and placebo (6 mg/kg of dextrose). At 50% 1RM, there was a significant effect of caffeine on mean velocity compared to control (effect size [ES] = 0.29; p = 0.003), but not when compared to placebo (ES = 0.09; p = 0.478). At 75% 1RM, there was a significant effect of caffeine on mean velocity compared to placebo (ES = 0.34; p = 0.001), and compared to control (ES = 0.32; p < 0.001). At 90% 1RM, there was a significant effect of caffeine on mean velocity compared to placebo (ES = 0.36; p < 0.001), and compared to control (ES = 0.46; p < 0.001). There was no significant difference between placebo and control in any of the analyzed outcomes. When evaluated pre-exercise and post-exercise, 20% to 44% and 28% to 52% of all participants identified caffeine and placebo trials beyond random chance, respectively. Given that the blinding of the participants was generally effective, and that there were no significant ergogenic effects of placebo ingestion, the improvements in performance following caffeine ingestion can be mainly attributed to caffeine's physiological mechanisms of action.
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http://dx.doi.org/10.2478/hukin-2020-0023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7706645PMC
August 2020

Low-intensity resistance exercise with blood flow restriction and arterial stiffness in humans: A systematic review.

Scand J Med Sci Sports 2021 Mar 22;31(3):498-509. Epub 2020 Dec 22.

Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark.

Low-intensity resistance exercise with blood flow restriction exercise is an emerging type of exercise recognition worldwide. This systematic review evaluated the effects of low-intensity resistance exercise performed with concurrent blood flow restriction (LIRE-BFR) on acute and chronic measures of arterial stiffness in humans. A systematic search in six healthcare science databases and reference lists was conducted. Data selected for primary analysis consisted of post-intervention changes in arterial stiffness markers. This systematic review included randomized and non-randomized controlled trials of LIRE-BFR in humans. 156 articles were initially identified, 15 of which met inclusion criteria. Ten studies were excluded because they did not match predefined arterial stiffness markers. Thus, five articles were included in this review: two acute studies (N = 39 individuals, age = 20-30 years old, 30.8% women and 69.2% men) and three longitudinal studies (N = 51 individuals, age = 24-86-years old, 41.2% women and 58.8% men). Acute LIRE-BFR demonstrated both positive and negative effects on arterial stiffness in healthy young people. In contrast, longitudinal studies reported neutral effects in healthy young and older people. In conclusion, LIRE-BFR applied to the upper and lower limbs may acutely induce increases in central blood pressure and pulse wave velocity in healthy young people, whereas LIRE-BFR for the lower limbs may elicit positive effects related to indirect markers of arterial stiffness. Moreover, longitudinal LIRE-BFR studies showed no changes in arterial stiffness in young and older people. Hence, LIRE-BFR should be prescribed with a degree of caution to avoid non-intended responses in arterial stiffness markers in humans.
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http://dx.doi.org/10.1111/sms.13902DOI Listing
March 2021

CYP1A2 genotype and acute ergogenic effects of caffeine intake on exercise performance: a systematic review.

Eur J Nutr 2021 Apr 2;60(3):1181-1195. Epub 2020 Nov 2.

Faculty of Kinesiology, University of Zagreb, Zagreb, Croatia.

Purpose: To systematically review studies that examined the influence of the CYP1A2 -163C>A polymorphism on the ergogenic effects of caffeine and to discuss some of the reasons for the discrepancies in findings between the studies.

Methods: This review was performed in accordance with the PRISMA guidelines. The search for studies was performed through nine databases.

Results: Seventeen studies were included in the review. Based on the included studies, it seems that individuals with the AA or AC/CC genotype may experience an increase in performance following caffeine ingestion. Significant differences between genotypes were found in four studies, and all four reported a more favorable response in the AA vs. AC/CC genotype. These results suggest that if there is an actual genotype-related effect of acute caffeine supplementation, it might be in that direction. In the studies that reported such data for aerobic endurance, the findings are specific to male participants performing cycling time trials (distances of ≥ 10 km) and ingesting caffeine 60 min before exercise. For high-intensity exercise, two studies reported that genotype variations determined the response to caffeine ingestion, even though the differences were either small (~ 1 additional repetition in high-load resistance exercise set performed to muscular failure) or inconsistent (i.e., observed only in one out of eight performance tests).

Conclusions: CYP1A2 genotype variations may modulate caffeine's ergogenic effects, but the differences between genotypes were small, inconsistent, or limited to specific exercise scenarios. Future studies with larger sample sizes are needed to fully elucidate this research area.
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http://dx.doi.org/10.1007/s00394-020-02427-6DOI Listing
April 2021

Effect of 12 Weeks of Resistance Training on Motor Coordination and Dynamic Balance of Older Woman.

Rejuvenation Res 2021 Jun 11;24(3):191-197. Epub 2020 Dec 11.

Research Group on Metabolism, Nutrition and Strength Training, Federal University of Paraná, Curitiba, Brazil.

Resistance training (RT) is considered a viable strategy to enhance the autonomy and functionality of older populations. We randomized 49 older women (64.2 ± 3.8) into one of two groups: an intervention group (IG) ( = 29) that performed regimented RT or a nontraining control group (CG) ( = 20). The RT protocol was carried out three times a week for both the upper and lower limbs over a 12-week study period. A 30-second arm flexion test was used to test upper limb endurance and a 30-second chair stand test was used to analyze lower limb endurance. Dynamic balance was tested by a Y balance test normalized by leg length. A Soda Pop test was employed to analyze coordination. Results showed significant improvements in IG versus CG in both upper limb (19.50 ± 1.52 vs. 11.40 ± 2.87,  = 0.001) and lower limb muscular endurance (14.90 ± 3.10 vs. 26.56 ± 3.17,  = 0.001). Moreover, the training group showed superior improvements in anterior and posterolateral balance compared to CG (63.9% ± 3.1% to 70.2 ± 2.1 and 88.1 ± 3.9 to 94.2 ± 2.7 with  = 0.001, respectively). There were no significant differences in coordination outcomes between groups. In conclusion, we demonstrate that RT is effective in developing muscular endurance and dynamic balance in postmenopausal women, but does not influence muscular coordination in the measures studied. Study registered in the Brazilian Registry Clinical Trials Registry (No. RBR-7MZ2KR).
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http://dx.doi.org/10.1089/rej.2020.2339DOI Listing
June 2021

Alterations in Body Composition, Resting Metabolic Rate, Muscular Strength, and Eating Behavior in Response to Natural Bodybuilding Competition Preparation: A Case Study.

J Strength Cond Res 2020 Nov;34(11):3124-3138

Trexler Fitness LLC, Raleigh, North Carolina.

Schoenfeld, BJ, Alto, A, Grgic, J, Tinsley, G, Haun, CT, Campbell, BI, Escalante, G, Sonmez, GT, Cote, G, Francis, A, and Trexler, ET. Alterations in body composition, resting metabolic rate, muscular strength, and eating behavior in response to natural bodybuilding competition preparation: A case study. J Strength Cond Res 34(11): 3124-3138, 2020-We carried out a prospective case study in a high-level amateur natural male bodybuilder throughout preparation for 4 competitions and during the ensuing postcontest recovery period. Laboratory testing was conducted monthly over a 1-year period, which included the following assessments: B-mode ultrasound evaluation of muscle thickness (MT), multifrequency bioelectrical impedance analysis, blood pressure and heart rate assessment, resting metabolic rate via indirect calorimetry, skinfold testing, vertical jump height, isometric lower-body strength testing, and a 3-factor eating questionnaire. Blood work (including testosterone, thyroid hormone, sex hormone binding globulin, glomerular filtration rate, blood urea nitrogen, aspartate aminotransferase, alanine aminotransferase, white blood count, albumin to globulin ratio, and lipoprotein A) was obtained separately from an outside laboratory at 4 time points. We also assessed the effectiveness of a carbohydrate (carb) deplete and carb load peaking strategy employed immediately before competition. The subject employed a high-volume, high-frequency, whole-body training program throughout the study period. Average daily nutritional intakes ranged from 1,953 to 3,415 kcal: 104-386 g carb; 253-263 g protein, and; 57-95 g lipid. Body fat was reduced to very low levels (∼5%) immediately before competition, but this corresponded with a loss of lean mass. Alterations in metabolism, hormonal status, explosive strength, and psychological aspects of eating were observed during precontest preparation; however, all of these variables recovered quickly postcompetition. The implementation of a carb depleteand carb load peaking strategy acutely increased MT and thus may be a viable precontest approach to maximize muscular aesthetics.
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http://dx.doi.org/10.1519/JSC.0000000000003816DOI Listing
November 2020
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