Publications by authors named "William J Kraemer"

328 Publications

Acute Effects of High-intensity Resistance Exercise on Cognitive Function.

J Sports Sci Med 2021 Sep 3;20(3):391-397. Epub 2021 May 3.

Department of Psychology, The Ohio State University, Columbus, OH, USA.

The purpose of the present study was to examine the influence of an acute bout of high-intensity resistance exercise on measures of cognitive function. Ten men (Mean ± SD: age = 24.4 ± 3.2 yrs; body mass = 85.7 ± 11.8 kg; height = 1.78 ± 0.08 m; 1 repetition maximum (1RM) = 139.0 ± 24.1 kg) gave informed consent and performed a high-intensity 6 sets of 10 repetitions of barbell back squat exercise at 80% 1RM with 2 minutes rest between sets. The Automated Neuropsychological Assessment Metrics (ANAM) was completed to assess various cognitive domains during the familiarization period, immediately before, and immediately after the high-intensity resistance exercise bout. The repeated measures ANOVAs for throughput scores (r·m) demonstrated significant mean differences for the Mathematical Processing task (MTH; < 0.001, η = 0.625) where pairwise comparisons demonstrated that the post-fatigue throughput (32.0 ± 8.8 r·m) was significantly greater than the pre-fatigue (23.8 ± 7.4 r·m, = 0.003, = 1.01) and the familiarization throughput (26.4 ± 5.3 r·m, = 0.024, = 0.77). The Coded Substitution-Delay task also demonstrated significant mean differences (CDD; = 0.027, η = 0.394) with pairwise comparisons demonstrating that the post-fatigue throughput (49.3 ± 14.4 r·m) was significantly less than the pre-fatigue throughput (63.2 ± 9.6 r·m, = 0.011, = 1.14). The repeated measures ANOVAs for reaction time (ms) demonstrated significant mean differences for MTH ( < 0.001, η = 0.624) where pairwise comparisons demonstrated that the post-fatigue reaction time (1885.2 ± 582.8 ms) was significantly less than the pre-fatigue (2518.2 ± 884.8 ms, = 0.005, = 0.85) and familiarization (2253.7 ± 567.6 ms, = 0.009, = 0.64) reaction times. The Go/No-Go task demonstrated significant mean differences (GNG; = 0.031, η = 0.320) with pairwise comparisons demonstrating that the post-fatigue (285.9 ± 16.3 ms) was significantly less than the pre-fatigue (298.5 ± 12.1 ms, = 0.006, = 0.88) reaction times. High-intensity resistance exercise may elicit domain-specific influences on cognitive function, characterized by the facilitation of simple cognitive tasks and impairments of complex cognitive tasks.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.52082/jssm.2021.391DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8256515PMC
September 2021

Anabolic-Androgenic Steroid Use in Sports, Health, and Society.

Med Sci Sports Exerc 2021 Aug;53(8):1778-1794

Department of Health and Exercise Science, The College of New Jersey, Ewing, NJ.

This consensus statement is an update of the 1987 American College of Sports Medicine (ACSM) position stand on the use of anabolic-androgenic steroids (AAS). Substantial data have been collected since the previous position stand, and AAS use patterns have changed significantly. The ACSM acknowledges that lawful and ethical therapeutic use of AAS is now an accepted mainstream treatment for several clinical disorders; however, there is increased recognition that AAS are commonly used illicitly to enhance performance and appearance in several segments of the population, including competitive athletes. The illicit use of AAS by competitive athletes is contrary to the rules and ethics of many sport governing bodies. Thus, the ACSM deplores the illicit use of AAS for athletic and recreational purposes. This consensus statement provides a brief history of AAS use, an update on the science of how we now understand AAS to be working metabolically/biochemically, potential side effects, the prevalence of use among athletes, and the use of AAS in clinical scenarios.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1249/MSS.0000000000002670DOI Listing
August 2021

Effects of Palm Stearin versus Butter in the Context of Low-Carbohydrate/High-Fat and High-Carbohydrate/Low-Fat Diets on Circulating Lipids in a Controlled Feeding Study in Healthy Humans.

Nutrients 2021 Jun 5;13(6). Epub 2021 Jun 5.

Department of Human Sciences, The Ohio State University, 305 Annie & John Glenn Ave, Columbus, OH 43210, USA.

Background: Foods rich in saturated fatty acids (SFAs) have been discouraged by virtue of their cholesterol-raising potential, but this effect is modulated by the food source and background level of carbohydrate.

Objective: We aimed to compare the consumption of palm stearin (PS) versus butter on circulating cholesterol responses in the setting of both a low-carbohydrate/high-fat (LC/HF) and high-carbohydrate/low-fat (HC/LF) diet in healthy subjects. We also explored effects on plasma lipoprotein particle distribution and fatty acid composition.

Methods: We performed a randomized, controlled-feeding, cross-over study that compared a PS- versus a Butter-based diet in a group of normocholesterolemic, non-obese adults. A controlled canola oil-based 'Run-In' diet preceded the experimental PS and Butter diets. All diets were eucaloric, provided for 3-weeks, and had the same macronutrient distribution but varied in primary fat source (40% of the total fat). The same Run-In and cross-over experiments were done in two separate groups who self-selected to either a LC/HF ( = 12) or a HC/LF ( = 12) diet track. The primary outcomes were low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein (HDL)-C, triglycerides, and LDL particle distribution.

Results: Compared to PS, Butter resulted in higher LDL-C in both the LC/HF (13.4%, = 0.003) and HC/LF (10.8%, = 0.002) groups, which was primarily attributed to large LDL I and LDL IIa particles. There were no differences between PS and Butter in HDL-C, triglycerides, or small LDL particles. Oxidized LDL was lower after PS than Butter in LC/HF ( = 0.011), but not the HC/LF group.

Conclusions: These results demonstrate that Butter raises LDL-C relative to PS in healthy normocholesterolemic adults regardless of background variations in carbohydrate and fat, an effect primarily attributed to larger cholesterol-rich LDL particles.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nu13061944DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8226735PMC
June 2021

Hormonal stress responses of growth hormone and insulin-like growth factor-I in highly resistance trained women and men.

Growth Horm IGF Res 2021 Aug 6;59:101407. Epub 2021 Jun 6.

Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA.

The purpose of this study was to examine the responses of growth hormone (GH) and insulin-like growth factor-I (IGFI) to intense heavy resistance exercise in highly trained men and women to determine what sex-dependent responses may exist. Subjects were highly resistance trained men (N = 8, Mean ± SD; age, yrs., 21 ± 1, height, cm, 175.3 ± 6.7, body mass, kg, 87.0 ± 18.5, % body fat, 15.2 ± 5.4, squat X body mass, 2.1 ± 0.4; and women (N = 7; Mean ± SD, age, yrs. 24 ± 5, height, cm 164.6 ± 6.7, body mass, kg 76.4 ± 8.8, % body fat, 26.9 ± 5.3, squat X body mass, 1.7 ± 0.6). An acute resistance exercise test protocol (ARET) consisted of 6 sets of 10 repetitions at 80% of the 1 RM with 2 min rest between sets was used as the stressor. Blood samples were obtained pre-exercise, after 3 sets, and then immediately after exercise (IP), 5, 15, 30, and 70 min post-exercise for determination of blood lactate (HLa), and plasma glucose, insulin, cortisol, and GH. Determination of plasma concentrations of IGFI, IGF binding proteins 1, 2, and 3 along with molecular weight isoform factions were determined at pre, IP and 70 min. GH significantly (P ≤ 0.05) increased at all time points with resting concentrations significantly higher in women. Significant increases were observed for HLa, glucose, insulin, and cortisol with exercise and into recovery with no sex-dependent observations. Women showed IGF-I values that were higher than men at all times points with both seeing exercise increases. IGFBP-1 and 2 showed increase with exercise with no sex-dependent differences. IGFBP-3 concentrations were higher in women at all-time points with no exercise induced changes. Both women and men saw an exercise induced increase with significantly higher values in GH in only the mid-range (30-60 kD) isoform.  Only women saw an exercise induced increase with significantly higher values for IGF fractions only in the mid-range (30-60 kD) isoform, which were significantly greater than the men at the IP and 70 min post-exercise time points. In conclusion, the salient findings of this investigation were that in highly resistance trained men and women, sexual dimorphisms exist but appear different from our prior work in untrained men and women and appear to support a sexual dimorphism related to compensatory aspects in women for anabolic mediating mechanisms in cellular interactions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ghir.2021.101407DOI Listing
August 2021

Radiotherapy before or during androgen-deprivation therapy does not blunt the exercise-induced body composition protective effects in prostate cancer patients: A secondary analysis of two randomized controlled trials.

Exp Gerontol 2021 08 27;151:111427. Epub 2021 May 27.

Exercise Medicine Research Institute, Edith Cowan University, Joondalup, Australia; School of Medical and Health Sciences, Edith Cowan University, Joondalup, Australia.

Background: Androgen deprivation therapy (ADT) contributes to lean mass loss and adiposity increases in prostate cancer patients. Radiotherapy during ADT might act synergistically and further worsen body composition. Previous investigations have shown that resistance training is an effective method of preserving body composition during ADT, however, most have not accounted for direct or indirect effects of other therapies, such as radiotherapy. Therefore, the purpose of this study was to examine training adaptations of the tissue composition in patients receiving radiation therapy (RT) prior or during ADT.

Methods: Analyses were performed by combining data from two previous trials for a total of 131 prostate cancer patients who underwent a combination of resistance and aerobic exercise training (N = 70, age: 68.9 ± 6.6y, RT-before: 13%, RT-during: 14%) or usual care (N = 61, age: 67.5 ± 7.9y, RT-before: 16%, RT-during: 20%) for 3 months upon ADT onset. Whole-body lean mass (LM), fat percentage and appendicular LM were determined by dual energy x-ray absorptiometry, and lower-leg muscle area and density by peripheral computed tomography at baseline (onset of ADT) and at 3 months post-intervention. Covariates included RT prior and during the intervention, demographic characteristics, physical symptoms, and chronic conditions.

Results: Radiotherapy before or during the intervention did not affect body composition. Only the usual care group experienced a significant decrease in whole-body LM (-994 ± 150 g, P < 0.001) and appendicular LM (-126 ± 19 g, P < 0.001), and an increase in whole-body fat percentage (1% ± 0.1%, P < 0.001). There was no change in lower-leg muscle area or density in either group.

Conclusion: We suggest that radiation prior to and during ADT does not interfere with the beneficial effects of exercise training on body composition in men with prostate cancer.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exger.2021.111427DOI Listing
August 2021

The Effects of a 6-Week Controlled, Hypocaloric Ketogenic Diet, With and Without Exogenous Ketone Salts, on Body Composition Responses.

Front Nutr 2021 24;8:618520. Epub 2021 Mar 24.

Department of Human Sciences, The Ohio State University, Columbus, OH, United States.

Ketogenic diets () that elevate beta-hydroxybutyrate () promote weight and fat loss. Exogenous ketones, such as ketone salts (), also elevate BHB concentrations with the potential to protect against muscle loss during caloric restriction. Whether augmenting ketosis with KS impacts body composition responses to a well-formulated KD remains unknown. To explore the effects of energy-matched, hypocaloric KD feeding (<50 g carbohydrates/day; 1.5 g/kg/day protein), with and without the inclusion of KS, on weight loss and body composition responses. Overweight and obese adults were provided a precisely defined hypocaloric KD (~75% of energy expenditure) for 6 weeks. In a double-blind manner, subjects were randomly assigned to receive ~24 g/day of a racemic BHB-salt (KD + KS; = 12) or placebo (KD + PL; = 13). A matched comparison group ( = 12) was separately assigned to an isoenergetic/isonitrogenous low-fat diet (LFD). Body composition parameters were assessed by dual x-ray absorptiometry and magnetic resonance imaging. The KD induced nutritional ketosis (>1.0 mM capillary BHB) throughout the study ( < 0.001), with higher fasting concentrations observed in KD + KS than KD + PL for the first 2 weeks ( < 0.05). There were decreases in body mass, whole body fat and lean mass, mid-thigh muscle cross-sectional area, and both visceral and subcutaneous adipose tissues ( < 0.001), but no group differences between the two KDs or with the LFD. Urine nitrogen excretion was significantly higher in KD + PL than LFD ( < 0.01) and trended higher in KD + PL compared to KD + KS ( = 0.076), whereas the nitrogen excretion during KD + KS was similar to LFD ( > 0.05). Energy-matched hypocaloric ketogenic diets favorably affected body composition but were not further impacted by administration of an exogenous BHB-salt that augmented ketosis. The trend for less nitrogen loss with the BHB-salt, if manifested over a longer period of time, may contribute to preserved lean mass.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnut.2021.618520DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8044842PMC
March 2021

Comparison of Ketogenic Diets with and without Ketone Salts versus a Low-Fat Diet: Liver Fat Responses in Overweight Adults.

Nutrients 2021 Mar 17;13(3). Epub 2021 Mar 17.

Department of Human Sciences, The Ohio State University, Columbus, OH 43201, USA.

Ketogenic diets (KDs) often contain high levels of saturated fat, which may increase liver fat, but the lower carbohydrate intake may have the opposite effect. Using a controlled feeding design, we compared liver fat responses to a hypocaloric KD with a placebo (PL) versus an energy-matched low-fat diet (LFD) in overweight adults. We also examined the added effect of a ketone supplement (KS). Overweight adults were randomized to a 6-week KD (KD + PL) or a KD with KS (KD + KS); an LFD group was recruited separately. All diets were estimated to provide 75% of energy expenditure. Weight loss was similar between groups ( > 0.05). Liver fat assessed by magnetic resonance imaging decreased after 6 week ( = 0.004) with no group differences ( > 0.05). A subset with nonalcoholic fatty liver disease (NAFLD) (liver fat > 5%, = 12) showed a greater reduction in liver fat, but no group differences. In KD participants with NAFLD, 92% of the variability in change in liver fat was explained by baseline liver fat ( < 0.001). A short-term hypocaloric KD high in saturated fat does not adversely impact liver health and is not impacted by exogenous ketones. Hypocaloric low-fat and KDs can both be used in the short-term to significantly reduce liver fat in individuals with NAFLD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/nu13030966DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8002465PMC
March 2021

Differences in brain structure and theta burst stimulation-induced plasticity implicate the corticomotor system in loss of function after musculoskeletal injury.

J Neurophysiol 2021 04 17;125(4):1006-1021. Epub 2021 Feb 17.

Department of Human Sciences, The Ohio State University, Columbus, Ohio.

Traumatic musculoskeletal injury (MSI) may involve changes in corticomotor structure and function, but direct evidence is needed. To determine the corticomotor basis of MSI, we examined interactions among skeletomotor function, corticospinal excitability, corticomotor structure (cortical thickness and white matter microstructure), and intermittent theta burst stimulation (iTBS)-induced plasticity. Nine women with unilateral anterior cruciate ligament rupture (ACL) 3.2 ± 1.1 yr prior to the study and 11 matched controls (CON) completed an MRI session followed by an offline plasticity-probing protocol using a randomized, sham-controlled, double-blind, cross-over study design. iTBS was applied to the injured (ACL) or nondominant (CON) motor cortex leg representation (M1) with plasticity assessed based on changes in skeletomotor function and corticospinal excitability compared with sham iTBS. The results showed persistent loss of function in the injured quadriceps, compensatory adaptations in the uninjured quadriceps and both hamstrings, and injury-specific increases in corticospinal excitability. Injury was associated with lateralized reductions in paracentral lobule thickness, greater centrality of nonleg corticomotor regions, and increased primary somatosensory cortex leg area inefficiency and eccentricity. Individual responses to iTBS were consistent with the principles of homeostatic metaplasticity; corresponded to injury-related differences in skeletomotor function, corticospinal excitability, and corticomotor structure; and suggested that corticomotor adaptations involve both hemispheres. Moreover, iTBS normalized skeletomotor function and corticospinal excitability in ACL. The results of this investigation directly confirm corticomotor involvement in chronic loss of function after traumatic MSI, emphasize the sensitivity of the corticomotor system to skeletomotor events and behaviors, and raise the possibility that brain-targeted therapies could improve recovery. Traumatic musculoskeletal injuries may involve adaptive changes in the brain that contribute to loss of function. Our combination of neuroimaging and theta burst transcranial magnetic stimulation (iTBS) revealed distinct patterns of iTBS-induced plasticity that normalized differences in muscle and brain function evident years after unilateral knee ligament rupture. Individual responses to iTBS corresponded to injury-specific differences in brain structure and physiological activity, depended on skeletomotor deficit severity, and suggested that corticomotor adaptations involve both hemispheres.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/jn.00689.2020DOI Listing
April 2021

Resistance Training Load Effects on Muscle Hypertrophy and Strength Gain: Systematic Review and Network Meta-analysis.

Med Sci Sports Exerc 2021 06;53(6):1206-1216

Exercise Research Laboratory, School of Physical Education, Physiotherapy and Dance, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, BRAZIL.

Purpose: This study aimed to analyze the effect of resistance training (RT) performed until volitional failure with low, moderate, and high loads on muscle hypertrophy and muscle strength in healthy adults and to assess the possible participant-, design-, and training-related covariates that may affect the adaptations.

Methods: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, MEDLINE, CINAHL, EMBASE, SPORTDiscus, and Web of Science databases were searched. Including only studies that performed sets to volitional failure, the effects of low- (>15 repetitions maximum (RM)), moderate- (9-15 RM), and high-load (≤8 RM) RTs were examined in healthy adults. Network meta-analysis was undertaken to calculate the standardized mean difference (SMD) between RT loads in overall and subgroup analyses involving studies deemed of high quality. Associations between participant-, design-, and training-related covariates with SMD were assessed by univariate and multivariate network meta-regression analyses.

Results: Twenty-eight studies involving 747 healthy adults were included. Although no differences in muscle hypertrophy between RT loads were found in overall (P = 0.113-0.469) or subgroup analysis (P = 0.871-0.995), greater effects were observed in untrained participants (P = 0.033) and participants with some training background who undertook more RT sessions (P = 0.031-0.045). Muscle strength improvement was superior for both high-load and moderate-load compared with low-load RT in overall and subgroup analysis (SMD, 0.60-0.63 and 0.34-0.35, respectively; P < 0.001-0.003), with a nonsignificant but superior effect for high compared with moderate load (SMD, 0.26-0.28, P = 0.068).

Conclusions: Although muscle hypertrophy improvements seem to be load independent, increases in muscle strength are superior in high-load RT programs. Untrained participants exhibit greater muscle hypertrophy, whereas undertaking more RT sessions provides superior gains in those with previous training experience.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1249/MSS.0000000000002585DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8126497PMC
June 2021

Body Composition in Elite Strongman Competitors.

J Strength Cond Res 2020 Dec;34(12):3326-3330

Division of Sports Medicine, Department of Orthopedics, Miller School of Medicine, University of Miami Sports Medicine Institute, Coral Gables, Florida.

Kraemer, WJ, Caldwell, LK, Post, EM, DuPont, WH, Martini, ER, Ratamess, NA, Szivak, TK, Shurley, JP, Beeler, MK, Volek, JS, Maresh, CM, Todd, JS, Walrod, BJ, Hyde, PN, Fairman, C, and Best, TM. Body composition in elite strongman competitors. J Strength Cond Res 34(12): 3326-3330, 2020-The purpose of this descriptive investigation was to characterize a group of elite strongman competitors to document the body composition of this unique population of strength athletes. Data were collected from eligible competitors as part of a health screening program conducted over 5 consecutive years. Imaging was acquired using dual-energy x-ray absorptiometry (DXA), providing total body measures of fat mass, lean mass, and bone mineral content (BMC). Year to year, testing groups showed a homogenous grouping of anthropometric, body composition, and bone density metrics. Composite averages were calculated to provide an anthropometric profile of the elite strongman competitor (N = 18; mean ± SD): age, 33.0 ± 5.2 years; body height, 187.4 ± 7.1 cm; body mass, 152.9 ± 19.3 kg; body mass index, 43.5 ± 4.8 kg·m; fat mass, 30.9 ± 11.1 kg; lean mass, 118.0 ± 11.7 kg, body fat, 18.7 ± 6.2%, total BMC, 5.23 ± 0.41 kg, and bone mineral density, 1.78 ± 0.14 g·cm. These data demonstrate that elite strongman competitors are among the largest human male athletes, and in some cases, they are at the extreme limits reported for body size and structure. Elite strongman competitors undergo a high degree of mechanical stress, providing further insight into the potent role of physical training in mediating structural remodeling even into adulthood. Such data provide a glimpse into a unique group of competitive athletes pushing the limits not only of human performance but also of human physiology.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1519/JSC.0000000000003763DOI Listing
December 2020

Recovery using "float" from high intensity stress on growth hormone-like molecules in resistance trained men.

Growth Horm IGF Res 2020 12 25;55:101355. Epub 2020 Sep 25.

Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, United States of America.

Objective: The purpose of this study was to examine the influence of a novel "floatation-restricted environmental stimulation therapy" (floatation-REST) on growth hormone responses to an intense resistance exercise stress.

Design: Nine resistance trained men (age: 23.4 ± 2.5 yrs.; height: 175.3 ± 5.4 cm; body mass: 85.3 ± 7.9 kg) completed a balanced, crossover-controlled study design with two identical exercise trials, differing only in post-exercise recovery intervention (i.e., control or floatation-REST). A two-week washout period was used between experimental conditions. Plasma lactate was measured pre-exercise, immediately post-exercise and after the 1 h. recovery interventions. Plasma iGH was measured pre-exercise, immediately-post exercise, and after the recovery intervention, as well as 24 h and 48 h after the exercise test. The bGH-L was measured only at pre-exercise and following each recovery intervention.

Results: For both experimental conditions, a significant (P ≤ 0.05) increase in lactate concentrations were observed immediately post-exercise (~14 mmol • L-1) and remained slightly elevated after the recovery condition. The same pattern of responses was observed for iGH with no differences from resting values at 24 and 48 h of recovery. The bGH-L showed no exercise-induced changes following recovery with either treatment condition, however concentration values were dramatically lower than ever reported.

Conclusion: The use of floatation-REST therapy immediately following intense resistance exercise does not appear to influence anterior pituitary function in highly resistance trained men. However, the lower values of bGH suggest dramatically different molecular processing mechanisms at work in this highly trained population.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ghir.2020.101355DOI Listing
December 2020

A ketogenic diet combined with exercise alters mitochondrial function in human skeletal muscle while improving metabolic health.

Am J Physiol Endocrinol Metab 2020 12 28;319(6):E995-E1007. Epub 2020 Sep 28.

OSU Interdisciplinary PhD Program in Nutrition, Department of Human Sciences, The Ohio State University, Columbus, Ohio.

Animal data indicate that ketogenic diets are associated with improved mitochondrial function, but human data are lacking. We aimed to characterize skeletal muscle mitochondrial changes in response to a ketogenic diet combined with exercise training in healthy individuals. Twenty-nine physically active adults completed a 12-wk supervised exercise program after self-selection into a ketogenic diet (KD, = 15) group or maintenance of their habitual mixed diet (MD, = 14). Measures of metabolic health and muscle biopsies (vastus lateralis) were obtained before and after the intervention. Mitochondria were isolated from muscle and studied after exposure to carbohydrate (pyruvate), fat (palmitoyl-l-carnitine), and ketone (β-hydroxybutyrate+acetoacetate) substrates. Compared with MD, the KD resulted in increased whole body resting fat oxidation ( < 0.001) and decreased fasting insulin ( = 0.019), insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR), = 0.022], and visceral fat ( < 0.001). The KD altered mitochondrial function as evidenced by increases in mitochondrial respiratory control ratio (19%, = 0.009), ATP production (36%, = 0.028), and ATP/HO (36%, = 0.033) with the fat-based substrate. ATP production with the ketone-based substrate was four to eight times lower than with other substrates, indicating minimal oxidation. The KD resulted in a small decrease in muscle glycogen (14%, = 0.035) and an increase in muscle triglyceride (81%, = 0.006). These results expand our understanding of human adaptation to a ketogenic diet combined with exercise. In conjunction with weight loss, we observed altered skeletal muscle mitochondrial function and efficiency, an effect that may contribute to the therapeutic use of ketogenic diets in various clinical conditions, especially those associated with insulin resistance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1152/ajpendo.00305.2020DOI Listing
December 2020

Growth Hormone and Insulin-like Growth Factor-I Molecular Weight Isoform Responses to Resistance Exercise Are Sex-Dependent.

Front Endocrinol (Lausanne) 2020 21;11:571. Epub 2020 Aug 21.

Military Performance Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA, United States.

To determine if acute resistance exercise-induced increases in growth hormone (GH) and insulin-like growth factor-I (IGF-I) were differentially responsive for one or more molecular weight (MW) isoforms and if these responses were sex-dependent. College-aged men ( = 10) and women ( = 10) performed an acute resistance exercise test (ARET; 6 sets, 10 repetition maximum (10-RM) squat, 2-min inter-set rest). Serum aliquots from blood drawn Pre-, Mid-, and Post-ARET (0, +15, and +30-min post) were processed using High Performance Liquid Chromatography (HPLC) fractionation and pooled into 3 MW fractions (Fr.A: >60; Fr.B: 30-60; Fr.C: <30 kDa). We observed a hierarchy of serum protein collected among GH fractions across all time points independent of sex (Fr.C > Fr.A > Fr.B, ≤ 0.03). Sex × time interactions indicated that women experienced earlier and augmented increases in all serum GH MW isoform fraction pools ( < 0.05); however, men demonstrated delayed and sustained GH elevations ( < 0.01) in all fractions through +30-min of recovery. Similarly, we observed a sex-independent hierarchy among IGF-I MW fraction pools (Fr.A > Fr.B > Fr.C, ≤ 0.01). Furthermore, we observed increases in IGF-I Fr. A (ternary complexes) in men only ( ≤ 0.05), and increases in Fr.C (free/unbound IGF-I) in women only ( ≤ 0.05) vs. baseline, respectively. These data indicate that the processing of GH and IGF-I isoforms from the somatotrophs and hepatocytes are differential in their response to strenuous resistance exercise and reflect both temporal and sex-related differences.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fendo.2020.00571DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7472848PMC
May 2021

Resistance Training and Milk-Substitution Enhance Body Composition and Bone Health in Adolescent Girls.

J Am Coll Nutr 2021 Mar-Apr;40(3):193-210. Epub 2020 Jun 10.

Department of Human Sciences, The Ohio State University, Columbus, Ohio, USA.

Increased soft-drink consumption has contributed to poor calcium intake with 90% of adolescent girls consuming less than the RDA for calcium. The purpose of this investigation was to determine the independent and additive effects of two interventions (milk and resistance training) on nutrient adequacy, body composition, and bone health in adolescent girls. The experimental design consisted of four experimental groups of adolescent girls 14-17 years of age: (1) Milk + resistance training [MRT];  = 15; (2) Resistance training only [RT];  = 15; (3) Milk only [M]  = 20; (4) Control [C]  = 16. A few significant differences were observed at baseline between the groups for subject characteristics. Testing was performed pre and post-12 week training period for all groups. Milk was provided (3, 8 oz servings) for both the MRT and the M groups. The MRT group and the RT groups performed a supervised periodized resistance training program consisting of supervised one-hour exercise sessions 3 d/wk (M, W, F) for 12 wk. Baseline dietary data was collected utilizing the NUT-P-FFQ and/or a 120 item FFQ developed by the Fred Hutchinson Cancer Research Center (Seattle, Washington). Body composition was measured in the morning after an overnight fast using dual-energy X-ray absorptiometry (DXA) with a total body scanner (Prodigy, Lunar Corporation, Madison, WI). A whole body scan for bone density and lumbar spine scans were performed on all subjects. Maximal strength of the upper and lower body was assessed via a one-repetition maximum (1-RM) squat and bench press exercise protocols. Significance was set at  ≤ 0.05. Significant differences in nutrient intakes between groups generally reflected the nutrient composition of milk with greater intakes of protein and improved nutrient adequacy for several B vitamins, vitamin A, vitamin D, calcium, magnesium, phosphorus, potassium, and zinc. Mean calcium intake was 758 and 1581 mg/d, in the non-milk and milk groups, respectively, with 100% of girls in the milk groups consuming > RDA of 1300 mg/d. There were no effects of milk on body composition or muscle performance, but resistance training had a main effect and significantly increased body mass, lean body mass, muscle strength, and muscle endurance. There was a main effect of milk and resistance training on several measures of bone mineral density (BMD). Changes in whole body BMD in the M, RT, MRT, and CON were 0.45, 0.52, 1.32, and -0.19%, respectively ( < 0.01). Over the course of 12 weeks the effects of 1300 mg/d of calcium in the form of fluid milk combined with a heavy resistance training program resulted in the additive effects of greater nutrient adequacy and BMD in adolescent girls. While further studies are needed, combining increased milk consumption with resistance training appears to optimize bone health in adolescent girls.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07315724.2020.1770636DOI Listing
June 2020

Handgrip Strength Asymmetry and Weakness are Differentially Associated with Functional Limitations in Older Americans.

Int J Environ Res Public Health 2020 05 6;17(9). Epub 2020 May 6.

Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, Fargo, ND 58105, USA.

Handgrip strength (HGS) is a convent measure of strength capacity and associated with several age-related health conditions such as functional disability. Asymmetric strength between limbs has been linked to diminished function. Therefore, both HGS asymmetry and weakness could be associated with functional disability. We examined the associations of HGS asymmetry and weakness on functional limitations in a nationally representative sample of older Americans. : Data were analyzed from 2689 adults ≥ 60 years who participated in the 2011-2012 and 2013-2014 waves of the National Health and Nutrition Examination Survey. Weakness was defined as HGS < 26 kg for men and < 16 kg for women. Asymmetry was determined from the ratio of the dominant and non-dominant HGS. Those with HGS ratio 0.9-1.1 were considered as having HGS symmetry, and those outside this range had asymmetry. Compared to those with symmetric HGS and were not weak, those with weakness alone, and both weakness and HGS asymmetry had 2.47 (95% confidence interval [CI]: 1.14-5.35) and 3.93 (CI: 1.18-13.07) greater odds for functional limitations, respectively. However, HGS asymmetry alone was not associated with functional limitations (odds ratio: 0.80; CI: 0.62-1.03). The use of HGS asymmetry in protocols could improve the prognostic value of handgrip dynamometers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/ijerph17093231DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7246814PMC
May 2020

A Pre-Workout Supplement of Ketone Salts, Caffeine, and Amino Acids Improves High-Intensity Exercise Performance in Keto-Naïve and Keto-Adapted Individuals.

J Am Coll Nutr 2020 May-Jun;39(4):290-300. Epub 2020 Apr 24.

Department of Human Sciences, The Ohio State University, Columbus, Ohio, USA.

Acute ingestion of ketone supplements alters metabolism and potentially exercise performance. No studies to date have evaluated the impact of co-ingestion of ketone salts with caffeine and amino acids on high intensity exercise performance, and no data exists in Keto-Adapted individuals. We tested the performance and metabolic effects of a pre-workout supplement containing beta-hydroxybutyrate (BHB) salts, caffeine, and amino acids (KCA) in recreationally-active adults habitually consuming a mixed diet (Keto-Naïve; n = 12) or a ketogenic diet (Keto-Adapted; n = 12). In a randomized and balanced manner, subjects consumed either the KCA consisting of ∼7 g BHB (72% R-BHB and 28% S-BHB) with ∼100 mg of caffeine, and amino acids (leucine and taurine) or Water (control condition) 15 minutes prior to performing a staged cycle ergometer time to exhaustion test followed immediately by a 30 second Wingate test. Circulating total BHB concentrations increased rapidly after KCA ingestion in KN (154 to 732 μM) and KA (848 to 1,973 μM) subjects and stayed elevated throughout recovery in both groups. Plasma S-BHB increased >20-fold 15 minutes after KCA ingestion in both groups and remained elevated throughout recovery. Compared to Water, KCA ingestion increased time to exhaustion 8.3% in Keto-Naïve and 9.8% in Keto-Adapted subjects (P < 0.001). There was no difference in power output during the Wingate test between trials. Peak lactate immediately after exercise was higher after KCA (∼14.9 vs 12.7 mM). These results indicate that pre-exercise ingestion of a moderate dose of R- and S-BHB salts combined with caffeine, leucine and taurine improves high-intensity exercise performance to a similar extent in both Keto-Adapted and Keto-Naïve individuals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/07315724.2020.1752846DOI Listing
July 2021

Constitutive and Stress-Induced Psychomotor Cortical Responses to Compound K Supplementation.

Front Neurosci 2020 8;14:315. Epub 2020 Apr 8.

Department of Human Sciences, The Ohio State University, Columbus, OH, United States.

Isolated ginsenoside metabolites such as Compound K (CK) are of increasing interest to consumer and clinical populations as safe and non-pharmacological means to enhance psychomotor performance constitutively and in response to physical or cognitive stress. Nevertheless, the influence of CK on behavioral performance and EEG measures of cortical activity in humans is undetermined. In this double-blinded, placebo-controlled, counterbalanced within-group study, dose-dependent responses to CK (placebo, 160 and 960 mg) were assessed after 2 weeks of supplementation in nineteen healthy men and women (age: 39.9 ± 7.9 year, height 170.2 ± 8.6 cm, weight 79.7 ± 11.9 kg). Performance on upper- and lower-body choice reaction tests (CRTs) was tested before and after intense lower-body anaerobic exercise. Treatment- and stress-related changes in brain activity were measured with high-density EEG based on event-related potentials, oscillations, and source activity. Upper- (-12.3 ± 3.5 ms, = 0.002) and lower-body (-12.3 ± 4.9 ms, = 0.021) response times improved after exercise, with no difference between treatments (upper: = 0.354; lower: = 0.926). Analysis of cortical activity in sensor and source space revealed global increases in cortical arousal after exercise. CK increased activity in cortical regions responsible for sustained attention and mitigated exercise-induced increases in arousal. Responses to exercise varied depending on task, but CK appeared to reduce sensory interference from lower-body exercise during an upper-body CRT and improve the general maintenance of task-relevant sensory processes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fnins.2020.00315DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7158875PMC
April 2020

Growth Hormone(s), Testosterone, Insulin-Like Growth Factors, and Cortisol: Roles and Integration for Cellular Development and Growth With Exercise.

Front Endocrinol (Lausanne) 2020 25;11:33. Epub 2020 Feb 25.

Quest Diagnostics, Secaucus, NJ, United States.

Hormones are largely responsible for the integrated communication of several physiological systems responsible for modulating cellular growth and development. Although the specific hormonal influence must be considered within the context of the entire endocrine system and its relationship with other physiological systems, three key hormones are considered the "anabolic giants" in cellular growth and repair: testosterone, the growth hormone superfamily, and the insulin-like growth factor (IGF) superfamily. In addition to these anabolic hormones, glucocorticoids, mainly cortisol must also be considered because of their profound opposing influence on human skeletal muscle anabolism in many instances. This review presents emerging research on: (1) Testosterone signaling pathways, responses, and adaptations to resistance training; (2) Growth hormone: presents new complexity with exercise stress; (3) Current perspectives on IGF-I and physiological adaptations and complexity these hormones as related to training; and (4) Glucocorticoid roles in integrated communication for anabolic/catabolic signaling. Specifically, the review describes (1) Testosterone as the primary anabolic hormone, with an anabolic influence largely dictated primarily by genomic and possible non-genomic signaling, satellite cell activation, interaction with other anabolic signaling pathways, upregulation or downregulation of the androgen receptor, and potential roles in co-activators and transcriptional activity; (2) Differential influences of growth hormones depending on the "type" of the hormone being assayed and the magnitude of the physiological stress; (3) The exquisite regulation of IGF-1 by a family of binding proteins (IGFBPs 1-6), which can either stimulate or inhibit biological action depending on binding; and (4) Circadian patterning and newly discovered variants of glucocorticoid isoforms largely dictating glucocorticoid sensitivity and catabolic, muscle sparing, or pathological influence. The downstream integrated anabolic and catabolic mechanisms of these hormones not only affect the ability of skeletal muscle to generate force; they also have implications for pharmaceutical treatments, aging, and prevalent chronic conditions such as metabolic syndrome, insulin resistance, and hypertension. Thus, advances in our understanding of hormones that impact anabolic: catabolic processes have relevance for athletes and the general population, alike.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fendo.2020.00033DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7052063PMC
February 2021

Absolute and Body Mass Index Normalized Handgrip Strength Percentiles by Gender, Ethnicity, and Hand Dominance in Americans.

Adv Geriatr Med Res 2020 31;2(1). Epub 2019 Dec 31.

Department of Human Sciences, The Ohio State University, Columbus, OH 43210, USA.

Background: Gender and ethnicity are factors which influence strength, and hand dominance could be a critical component of handgrip strength (HGS) testing. Providing such HGS percentiles across the lifespan may help to identify weakness-related health concerns. We sought to generate growth charts and curves for HGS by gender and ethnicity in a nationally-representative sample of Americans aged 6-80 years.

Methods: Data from 13,617 participants in the 2011-2012 and 2013-2014 waves of the National Health and Nutrition Examination Survey were analyzed. HGS was measured with a handgrip dynamometer. Age, gender, ethnicity, and hand dominance were self-reported. Body Mass Index (BMI) was calculated from height and body mass. Measures of absolute HGS and HGS normalized to BMI were separately included in parametric quantile regression analyses for determining the 10th-90th percentiles across ages by gender and ethnicity. Similar models were also conducted by hand dominance.

Results: Differences in absolute HGS and HGS normalized to BMI quantiles across ages existed for each ethnicity regardless of gender. In men, absolute HGS generally increased until about 25 years of age, began to decline around age 30 years, and regressed into older adulthood. In women, absolute HGS appeared to rise starting at age 6 years, peaked between 20 and 30 years of age, but was maintained into mid-life before declining in older adulthood. Similar results were found for HGS normalized to BMI.

Conclusions: Our findings provide percentile charts for HGS capacity that could be utilized for comparing individual measures of HGS to those from a United States population-representative sample.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.20900/agmr20200005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6954001PMC
December 2019

A Narrative Review of Handgrip Strength and Cognitive Functioning: Bringing a New Characteristic to Muscle Memory.

J Alzheimers Dis 2020 ;73(4):1265-1278

Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, Fargo, ND, USA.

Background: Measures of handgrip strength have not only emerged as a clinically viable screening tool for determining risk for morbidity, functional disability, and early mortality, but also for helping to identify cognitive deficits. However, the phenomena that links low handgrip strength with cognitive decline remains unclear. The role of the muscular and neural systems, and their adaptations to muscle strengthening activities over the life course, may provide important information for how age-related changes to muscle mass, strength, and neural capacity influence cognition. Moreover, disentangling how handgrip strength and cognitive function are associated may help to inform healthcare providers working with aging adults and guide targeted interventions aiming to preserve muscle and cognitive functioning.

Objective: To 1) highlight and summarize evidence examining the associations of handgrip strength and cognitive functioning, and 2) provide directions for future research in this area.

Methods: Articles from the PubMed database were searched from November 2018-May 2019. The search term algorithm, inclusion and exclusion criteria were pre-specified by investigators.

Results: Several cross-sectional and longitudinal studies have revealed that measures of handgrip strength were associated with cognitive declines regardless of age demographics and the presence of comorbidities.

Conclusion: Handgrip strength can be used in clinical and epidemiological settings for helping to determine the onset and progression of cognitive impairment. Future research should continue to examine how handgrip strength and cognitive function are linked.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3233/JAD-190856DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7063546PMC
May 2021

Bioactive growth hormone in humans: Controversies, complexities and concepts.

Growth Horm IGF Res 2020 02 27;50:9-22. Epub 2019 Nov 27.

Department of Human Sciences, The Ohio State University, Columbus, OH, 43210, United States of America. Electronic address:

Objective: To revisit a finding, first described in 1978, which documented existence of a pituitary growth factor that escaped detection by immunoassay, but which was active in the established rat tibia GH bioassay.

Methods: We present a narrative review of the evolution of growth hormone complexity, and its bio-detectability, from a historical perspective.

Results: In humans under the age of 60, physical training (i.e. aerobic endurance and resistance training) are stressors which preferentially stimulate release of bioactive GH (bGH) into the blood. Neuroanatomical studies indicate a) that nerve fibers directly innervate the human anterior pituitary and b) that hind limb muscle afferents, in both humans and rats, also modulate plasma bGH. In the pituitary gland itself, molecular variants of GH, somatotroph heterogeneity and cell plasticity all appear to play a role in regulation of this growth factor.

Conclusion: This review considers more recent findings on this often forgotten/neglected subject. Comparison testing of a) human plasma samples, b) sub-populations of separated rat pituitary somatotrophs or c) purified human pituitary peptides by GH bioassay vs immunoassay consistently yield conflicting results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ghir.2019.11.003DOI Listing
February 2020

Acute Neuromuscular and Hormonal Responses to Different Exercise Loadings Followed by a Sauna.

J Strength Cond Res 2020 Feb;34(2):313-322

Neuromuscular Research Center, Biology of Physical Activity.

Rissanen, JA, Häkkinen, A, Laukkanen, J, Kraemer, WJ, and Häkkinen, K. Acute neuromuscular and hormonal responses to different exercise loadings followed by a sauna. J Strength Cond Res 34(2): 313-322, 2020-The purpose of this study was to investigate acute responses of endurance (E + SA), strength (S + SA), and combined endurance and strength exercise (C + SA) followed by a traditional sauna bath (70° C, 18% relative humidity) on neuromuscular performance and serum hormone concentrations. Twenty-seven recreationally physically active men who were experienced with taking a sauna participated in the study. All the subjects performed a sauna bath only (SA) first as a control measurement followed by S + SA and E + SA (paired matched randomization) and C + SA. Subjects were measured PRE (before exercise), MID (immediately after exercise and before sauna), POST (after sauna), POST30min (30 minutes after sauna), and POST24h (24 hours after PRE). Maximal isometric leg press (ILPFmax) and bench press (IBPFmax) forces, maximal rate of force development (RFD) and countermovement vertical jump (CMVJ), serum testosterone (TES), cortisol (COR), and 22-kD growth hormone (GH22kD) concentrations were measured. All exercise loadings followed by a sauna decreased ILPFmax (-9 to -15%) and RFD (-20 to -26%) in POST. ILPFmax, RFD, and CMVJ remained at significantly (p ≤ 0.05) lowered levels after S + SA in POST24h. IBPFmax decreased in POST in S + SA and C + SA and remained lowered in POST24h. SA decreased ILPFmax and IBPFmax in POST and POST30min and remained lowered in ILPFmax (-4.1%) at POST24h. GH22kD, TES, and COR elevated significantly in all loadings measured in the afternoon in MID. SA only led to an elevation (15%) in TES in POST. The strength exercise followed by a sauna was the most fatiguing protocol for the neuromuscular performance. Traditional sauna bathing itself seems to be strenuous loading, and it may not be recommended 24 hours before the next training session. A sauna bath after the loadings did not further change the hormonal responses recorded after the exercise loadings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1519/JSC.0000000000003371DOI Listing
February 2020

Resistance Training for Older Adults: Position Statement From the National Strength and Conditioning Association.

J Strength Cond Res 2019 08;33(8):2019-2052

Department of Exercise and Sport Science, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina.

Fragala, MS, Cadore, EL, Dorgo, S, Izquierdo, M, Kraemer, WJ, Peterson, MD, and Ryan, ED. Resistance training for older adults: position statement from the national strength and conditioning association. J Strength Cond Res 33(8): 2019-2052, 2019-Aging, even in the absence of chronic disease, is associated with a variety of biological changes that can contribute to decreases in skeletal muscle mass, strength, and function. Such losses decrease physiologic resilience and increase vulnerability to catastrophic events. As such, strategies for both prevention and treatment are necessary for the health and well-being of older adults. The purpose of this Position Statement is to provide an overview of the current and relevant literature and provide evidence-based recommendations for resistance training for older adults. As presented in this Position Statement, current research has demonstrated that countering muscle disuse through resistance training is a powerful intervention to combat the loss of muscle strength and muscle mass, physiological vulnerability, and their debilitating consequences on physical functioning, mobility, independence, chronic disease management, psychological well-being, quality of life, and healthy life expectancy. This Position Statement provides evidence to support recommendations for successful resistance training in older adults related to 4 parts: (a) program design variables, (b) physiological adaptations, (c) functional benefits, and (d) considerations for frailty, sarcopenia, and other chronic conditions. The goal of this Position Statement is to a) help foster a more unified and holistic approach to resistance training for older adults, b) promote the health and functional benefits of resistance training for older adults, and c) prevent or minimize fears and other barriers to implementation of resistance training programs for older adults.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1519/JSC.0000000000003230DOI Listing
August 2019

Cold-water immersion blunts and delays increases in circulating testosterone and cytokines post-resistance exercise.

Eur J Appl Physiol 2019 Aug 20;119(8):1901-1907. Epub 2019 Jun 20.

Department of Human Sciences, The Ohio State University, 305 Annie & John Glenn Ave, Columbus, OH, 43210, USA.

Introduction: Cold-water immersion (CWI) is often used to promote recovery by reducing exercise-induced muscle damage, soreness, and inflammation. However, recent reports have cautioned that CWI may attenuate the adaptive response to resistance training.

Purpose: To determine the effect of post resistance-exercise CWI on circulating free testosterone (T) and cytokine (IL-6 and TNF-α) response.

Methods: Using a randomized and counterbalanced repeated-measures design, 11 resistance-trained men completed two workouts (6 sets of 10 repetitions of back squats at 80% of maximum load) a week apart after which they took part in either 15 min of CWI (15 °C) or passive recovery. T, IL-6, and TNFα were measured in blood samples taken before (PRE) and 5 (5POST), 15 (15POST), 30 (30POST), and 60 (60POST) min post-exercise and compared between treatments and over time.

Results: For T, a significant interaction effect of condition over time (p = 0.030) as well as greater relative concentrations of T in CON (Δ9.2%) than CWI (Δ-0.5%, p = 0.049) at 30POST were observed. In addition, at 60POST, T dropped below PRE values in CWI (Δ-10.4%, p = 0.028) but not in CON (Δ-1.6%, p = 0.850). A suppressed cytokine response was observed after CWI in IL-6 at 30POST (CWI: Δ4.9%, CON: Δ47.5%, p = 0.041) and TNFα at 15POST (CWI: Δ5.3%, CON: Δ17.0%, p = 0.022).

Conclusions: CWI blunted the T and cytokine response after a bout of resistance exercise. These results indicate that CWI results in an altered anabolic response and may help to explain the previous observation of attenuated hypertrophy when CWI is used after resistance exercise.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00421-019-04178-7DOI Listing
August 2019

Dietary carbohydrate restriction improves metabolic syndrome independent of weight loss.

JCI Insight 2019 06 20;4(12). Epub 2019 Jun 20.

Department of Human Sciences, The Ohio State University, Columbus, Ohio, USA.

BACKGROUNDMetabolic syndrome (MetS) is highly correlated with obesity and cardiovascular risk, but the importance of dietary carbohydrate independent of weight loss in MetS treatment remains controversial. Here, we test the theory that dietary carbohydrate intolerance (i.e., the inability to process carbohydrate in a healthy manner) rather than obesity per se is a fundamental feature of MetS.METHODSIndividuals who were obese with a diagnosis of MetS were fed three 4-week weight-maintenance diets that were low, moderate, and high in carbohydrate. Protein was constant and fat was exchanged isocalorically for carbohydrate across all diets.RESULTSDespite maintaining body mass, low-carbohydrate (LC) intake enhanced fat oxidation and was more effective in reversing MetS, especially high triglycerides, low HDL-C, and the small LDL subclass phenotype. Carbohydrate restriction also improved abnormal fatty acid composition, an emerging MetS feature. Despite containing 2.5 times more saturated fat than the high-carbohydrate diet, an LC diet decreased plasma total saturated fat and palmitoleate and increased arachidonate.CONCLUSIONConsistent with the perspective that MetS is a pathologic state that manifests as dietary carbohydrate intolerance, these results show that compared with eucaloric high-carbohydrate intake, LC/high-fat diets benefit MetS independent of whole-body or fat mass.TRIAL REGISTRATIONClinicalTrials.gov Identifier: NCT02918422.FUNDINGDairy Management Inc. and the Dutch Dairy Association.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.128308DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6629108PMC
June 2019

Changes of Hydration Measures in Elite National Collegiate Athletic Association Division I Wrestlers.

Int J Sports Physiol Perform 2019 Oct 2:1-4. Epub 2019 Oct 2.

Purpose: To evaluate the changes in the state of hydration in elite National Collegiate Athletic Association (NCAA) Division I college wrestlers during and after a season.

Methods: Ohio State University wrestling team members (N = 6; mean [SD] age = 19.6 [1.1] y; height = 171.6 [2.9] cm; body mass = 69.5 [8.1] kg) gave informed consent to participate in the investigation with measurements (ie, body mass, urine-specific gravity [USG; 2 methods], Visual Analog Scale thirst scale, plasma osmolality) obtained during and after the season.

Results: Measurements for USG, regardless of methods, were not significantly different between visits, but plasma osmolality was significantly (P = .001) higher at the beginning of the season-295.5 (4.9) mOsm·kg-1 compared with 279.6 (6.1) mOsm·kg-1 after the season. No changes in thirst ratings were observed, and the 2 measures of USG were highly correlated (r > .9, P = .000) at each time point, but USG and plasma osmolality were not related.

Conclusions: A paradox in the clinical interpretation of euhydration in the beginning of the season was observed with the USG, indicating that the wrestlers were properly hydrated, while the plasma osmolality showed they were not. Thus, the tracking of hydration status during the season is a concern when using only NCAA policies and procedures. The wrestlers did return to normal euhydration levels after the season on both biomarkers, which is remarkable, as previous studies have indicated that this may not happen because of the reregulation of the osmol-regulatory center in the brain.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1123/ijspp.2019-0059DOI Listing
October 2019

Extended Ketogenic Diet and Physical Training Intervention in Military Personnel.

Mil Med 2019 10;184(9-10):e538-e547

Department of Human Sciences, The Ohio State University, 305 Annie and John Glenn Avenue, Columbus, OH.

Introduction: Ketogenic diets (KDs) that elevate ketones into a range referred to as nutritional ketosis represent a possible nutrition approach to address the emerging physical readiness and obesity challenge in the military. An emerging body of evidence demonstrates broad-spectrum health benefits attributed to being in nutritional ketosis, but no studies have specifically explored the use of a KD in a military population using daily ketone monitoring to personalize the diet prescription.

Materials And Methods: To evaluate the feasibility, metabolic, and performance responses of an extended duration KD, healthy adults (n = 29) from various military branches participated in a supervised 12-wk exercise training program. Fifteen participants self-selected to an ad libitum KD guided by daily measures of capillary blood ketones and 14 continued their normal mixed diet (MD). A battery of tests were performed before and after the intervention to assess changes in body mass, body composition, visceral fat, liver fat, insulin sensitivity, resting energy metabolism, and physical performance.

Results: All KD subjects were in nutritional ketosis during the intervention as assessed by daily capillary beta-hydroxybutyrate (βHB) (mean βHB 1.2 mM reported 97% of all days) and showed higher rates of fat oxidation indicative of keto-adaptation. Despite no instruction regarding caloric intake, the KD group lost 7.7 kg body mass (range -3.5 to -13.6 kg), 5.1% whole-body percent fat (range -0.5 to -9.6%), 43.7% visceral fat (range 3.0 to -66.3%) (all p < 0.001), and had a 48% improvement in insulin sensitivity; there were no changes in the MD group. Adaptations in aerobic capacity, maximal strength, power, and military-specific obstacle course were similar between groups (p > 0.05).

Conclusions: US military personnel demonstrated high adherence to a KD and showed remarkable weight loss and improvements in body composition, including loss of visceral fat, without compromising physical performance adaptations to exercise training. Implementation of a KD represents a credible strategy to enhance overall health and readiness of military service members who could benefit from weight loss and improved body composition.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/milmed/usz046DOI Listing
October 2019

Blinding success of sham-controlled motor cortex intermittent theta burst stimulation based on participant perceptions.

Brain Stimul 2019 Jul - Aug;12(4):1058-1060. Epub 2019 Mar 6.

Department of Human Sciences, The Ohio State University, Columbus, OH, 43210, USA. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.brs.2019.03.004DOI Listing
March 2019

Trunk Muscle Strength After Lumbar Spine Fusion: A 12-Month Follow-up.

Neurospine 2019 Jun 15;16(2):332-338. Epub 2018 Oct 15.

Health Sciences, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.

Objective: The aim of this study was to investigate changes in trunk muscle strength 12 months after lumbar spine fusion (LSF) compared to preoperative strength.

Methods: A total of 194 patients (mean±standard deviation [SD] age, 61±21 years) who underwent LSF participated in this prospective longitudinal study. Physical measurements of the participants were made before surgery and 12 months postoperatively. Isometric trunk extension and flexion strength was measured using a strain-gauge dynamometer in the standing position. Strength changes were calculated. Regression analysis was performed to explore which factors predicted strength levels at 12 months postoperatively.

Results: The preoperative mean±SD extension strength was 205±144 N, which increased to 258±142 N (p<0.001) at the 12-month follow-up. Flexion strength increased from 295±172 N to 364±164 N (p<0.001). The preoperative extension/flexion strength ratio was 0.75±0.38 and remained similar (0.73±0.26) at 12 months postoperatively (p=0.39).

Conclusion: Although trunk muscle strength increased by 26% for extension and 23% for flexion at the 12-month postoperative follow-up, both values remained objectively low. In addition, flexion strength remained higher than extension strength, which indicates an imbalance between those muscle groups. Age, severe back pain, and low trunk muscle strength before surgery predicted low trunk muscle strength at 1 year after spinal fusion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.14245/ns.1836136.068DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6603846PMC
June 2019