Publications by authors named "Julian Alcazar"

30 Publications

  • Page 1 of 1

Relative sit-to-stand power: aging trajectories, functionally relevant cut-off points, and normative data in a large European cohort.

J Cachexia Sarcopenia Muscle 2021 Jul 3. Epub 2021 Jul 3.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

Background: A validated, standardized, and feasible test to assess muscle power in older adults has recently been reported: the sit-to-stand (STS) muscle power test. This investigation aimed to assess the relationship between relative STS power and age and to provide normative data, cut-off points, and minimal clinically important differences (MCID) for STS power measures in older women and men.

Methods: A total of 9320 older adults (6161 women and 3159 men) aged 60-103 years and 586 young and middle-aged adults (318 women and 268 men) aged 20-60 years were included in this cross-sectional study. Relative (normalized to body mass), allometric (normalized to height squared), and specific (normalized to legs muscle mass) muscle power values were assessed by the 30 s STS power test. Body composition was evaluated by dual energy X-ray absorptiometry and bioelectrical impedance analysis, and legs skeletal muscle index (SMI; normalized to height squared) was calculated. Habitual and maximal gait speed, timed up-and-go test, and 6 min walking distance were collected as physical performance measures, and participants were classified into two groups: well-functioning and mobility-limited older adults.

Results: Relative STS power was found to decrease between 30-50 years (-0.05 W·kg ·year ; P > 0.05), 50-80 years (-0.10 to -0.13 W·kg ·year ; P < 0.001), and above 80 years (-0.07 to -0.08 W·kg ·year ; P < 0.001). A total of 1129 older women (18%) and 510 older men (16%) presented mobility limitations. Mobility-limited older adults were older and exhibited lower relative, allometric, and specific power; higher body mass index (BMI) and legs SMI (both only in women); and lower legs SMI (only in men) than their well-functioning counterparts (all P < 0.05). Normative data and cut-off points for relative, allometric, and specific STS power and for BMI and legs SMI were reported. Low relative STS power occurred below 2.1 W·kg in women (area under the curve, AUC, [95% confidence interval, CI] = 0.85 [0.84-0.87]) and below 2.6 W·kg in men (AUC [95% CI] = 0.89 [0.87-0.91]). The age-adjusted odds ratios [95% CI] for mobility limitations in older women and men with low relative STS power were 10.6 [9.0-12.6] and 14.1 [10.9-18.2], respectively. MCID values for relative STS power were 0.33 W·kg in women and 0.42 W·kg in men.

Conclusions: Relative STS power decreased significantly after the age of 50 years and was negatively and strongly associated with mobility limitations. Our study provides normative data, functionally relevant cut-off points, and MCID values for STS power for their use in daily clinical practice.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcsm.12737DOI Listing
July 2021

Assessment of functional sit-to-stand muscle power: Cross-sectional trajectories across the lifespan.

Exp Gerontol 2021 Sep 9;152:111448. Epub 2021 Jun 9.

Geriatric Research Unit, Geriatric Department, Bispebjerg University Hospital, Copenhagen, Denmark; Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet-Glostrup University Hospital, Copenhagen, Denmark; Geriatric Research Unit, Department of Internal Medicine, Herlev-Gentofte University Hospital, Copenhagen, Denmark. Electronic address:

Background: The 30-s sit-to-stand (STS) muscle power test is a valid test to assess muscle power in older people; however, whether it may be used to assess trajectories of lower-limb muscle power through the adult lifespan is not known. This study evaluated the pattern and time course of variations in relative, allometric and specific STS muscle power throughout the lifespan.

Methods: Subjects participating in the Copenhagen Sarcopenia Study (729 women and 576 men; aged 20 to 93 years) were included. Lower-limb muscle power was assessed with the 30-s version of the STS muscle power test. Allometric, relative and specific STS power were calculated as absolute STS power normalized to height squared, body mass and leg lean mass as assessed by DXA, respectively.

Results: Relative STS muscle power tended to increase in women (0.08 ± 0.05 W·kg·yr; p = 0.082) and increased in men (0.14 ± 0.07 W·kg·yr; p = 0.046) between 20 and 30 years, followed by a slow decline (-0.05 ± 0.05 W·kg·yr and -0.06 ± 0.08 W·kg·yr, respectively; both p > 0.05) between 30 and 50 years. Then, relative STS power declined at an accelerated rate up to oldest age in men (-0.09 ± 0.02 W·kg·yr) and in women until the age of 75 (-0.09 ± 0.01 W·kg·yr) (both p < 0.001). A lower rate of decline was observed in women aged 75 and older (-0.04 ± 0.02 W·kg·yr; p = 0.039). Similar age-related patterns were noted for allometric and specific STS power.

Conclusions: The STS muscle power test appears to provide a feasible and inexpensive tool to monitor cross-sectional trajectories of muscle power throughout the lifespan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exger.2021.111448DOI Listing
September 2021

Threshold of Relative Muscle Power Required to Rise from a Chair and Mobility Limitations and Disability in Older Adults.

Med Sci Sports Exerc 2021 Jun 7. Epub 2021 Jun 7.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha. Toledo, Spain CIBER of Frailty and Healthy Aging (CIBERFES). Madrid, Spain Geriatric Research Unit, Department for Geriatric and Palliative Medicine, Bispebjerg and Frederiksberg University Hospital. Copenhagen, Denmark Geriatric Research Unit, Department of Internal Medicine, Herlev and Gentofte University Hospital, Denmark CopenAge - Copenhagen Center for Clinical Age Research, University of Copenhagen. Denmark Exercise and Health Laboratory, CIPER, Faculty of Human Motricity, University of Lisbon. Lisbon, Portugal. CIDEFES, Research Center in Sports, Physical Education and Exercise and Health, Lusofona University. Lisbon, Portugal Physical Activity, Sports and Health Research Group, Department of Movement Sciences, KU Leuven. Leuven, Belgium ImFine Research Group, Department of Health and Human Performance, Faculty of Science and Physical Activity and Sports Sciences, Polytechnic University of Madrid. Madrid, Spain CIBER of Pathophysiology of Obesity and Nutrition (CIBEROBN). Madrid, Spain Geriatric Department, Hospital Universitario de Getafe, Getafe, Spain Growth, Exercise, Nutrition, and Development Research Group, University of Zaragoza. Zaragoza, Spain Department of Internal Medicine, Geriatric Division, Amager and Hvidovre Hospital, Glostrup. Copenhagen, Denmark Geriatric Research Unit, Hospital Virgen del Valle, Complejo Hospitalario de Toledo. Toledo, Spain.

Purpose: Being able to rise from a chair is paramount for independent living and is strongly influenced by the ability of the lower limbs to exert mechanical power. This study assessed minimal thresholds of lower-limb relative muscle power required to perform the sit-to-stand (STS) task in older adults and its association with mobility limitations and disability.

Methods: A total of 11,583 older adults (age: 60-103 years old) participated in this investigation. The 5-rep and 30-s versions of the STS test were used to assess chair rising ability. Relative power was calculated by the STS muscle power test. The minimum thresholds of power required to perform the STS tests were derived from the minimum values (i.e. 'floor' effect) reported in the power tests through regression analyses. Mobility limitations and disability in activities of daily living (ADL) were recorded.

Results: For the average older man and woman, the thresholds to complete five STS repetitions were 1.1 and 1.0 W·kg-1, respectively, while the thresholds to complete one STS repetition were 0.3 W·kg-1 in both sexes. These thresholds increased linearly with height (5- and 1-rep, respectively: +0.13 and + 0.03 W·kg-1 per 10-cm increase; both p < 0.001), and did not differ by sex or testing condition (both p ≥ 0.259). All participants with relative power below the 5-rep threshold presented mobility limitations and 51 - 56% of women and 36 - 49% of men also showed disability in ADL (all χ2 ≥ 290.4; p < 0.001).

Conclusion: A minimum level of relative muscle power is required to rise from a chair independently, which depends on the individual height and is associated with increased mobility limitations and disability. This information will help interpret data yielded by the STS muscle power test and may contribute to the prevention and treatment of mobility limitations in older people.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1249/MSS.0000000000002717DOI Listing
June 2021

Dose-Response Relationship Between Velocity Loss During Resistance Training and Changes in the Squat Force-Velocity Relationship.

Int J Sports Physiol Perform 2021 May 27:1-10. Epub 2021 May 27.

Purpose: This study aimed to compare the adaptations provoked by various velocity loss (VL) thresholds used in resistance training on the squat force-velocity (F-V) relationship.

Methods: Sixty-four resistance-trained young men were randomly assigned to one of four 8-week resistance training programs (all 70%-85% 1-repetition maximum) using different VL thresholds (VL0 = 0%, VL10 = 10%, VL20 = 20%, and VL40 = 40%) in the squat exercise. The F-V relationship was assessed under unloaded and loaded conditions in squat. Linear and hyperbolic (Hill) F-V equations were used to calculate force at zero velocity (F0), velocity at zero force (V0), maximum muscle power (Pmax), and force produced at mean velocities ranging from 0.0 to 2.0 m·s-1. Changes in parameters derived from the F-V relationship were compared among groups using linear mixed models.

Results: Linear equations showed increases in F0 (120.7 N [89.4 to 152.1]) and Pmax (76.2 W [45.3 to 107.2]) and no changes in V0 (-0.02 m·s-1 [-0.11 to 0.06]) regardless of VL. Hyperbolic equations depicted increases in F0 (120.7 N [89.4 to 152.1]), V0 (1.13 m·s-1 [0.78 to 1.48]), and Pmax (198.5 W [160.5 to 236.6]) with changes in V0 being greater in VL0 and VL10 versus VL40 (both P < .001). All groups similarly improved force at 0.0 to 2.0 m·s-1 (all P < .001), although in general, effect sizes were greater in VL10 and VL20 versus VL0 and VL40 at velocities ≤0.5 m·s-1.

Conclusions: All groups improved linear and hyperbolic F0 and Pmax and hyperbolic V0 (except VL40). The dose-response relationship exhibited an inverted U-shape pattern at velocities ≤0.5 m·s-1 with VL10 and VL20 showing the greatest standardized changes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1123/ijspp.2020-0692DOI Listing
May 2021

Acute Physiological Response to Light- and Heavy-load Power-oriented Exercise in Older Adults.

Int J Sports Med 2021 Apr 26. Epub 2021 Apr 26.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

This study investigated the acute responses to volume-load-matched heavy-load (80% 1RM) versus light-load (40% 1RM) power-oriented resistance training sessions in well-functioning older adults. Using a randomized cross-over design, 15 volunteers completed each condition on a leg press. Neuromuscular (maximal isometric force and rate of force development) and functional performance (power during sit-to-stand test), lactate, and muscle damage biochemistry (creatine kinase, lactate dehydrogenase and C-reactive protein serum concentration) were assessed pre- and post-exercise. Performance declines were found after heavy-load (Cohen's d effect size (d); maximal isometric force=0.95 d; rate of force development=1.17 d; sit-to-stand power =0.38 d, all p<0.05) and light-load (maximal isometric force=0.45 d; rate of force development=0.9 d; sit-to-stand power=1.17 d, all p<0.05), while lactate concentration increased only after light-load (1.7 d, p=0.001). However, no differences were found between conditions (all p>0.05). Both conditions increased creatine kinase the day after exercise (marginal effect=0.75 d, p<0.001), but no other blood markers increased (all, p>0.05). Irrespective of the load used, power training induced non-clinically significant decreases in sit-to-stand performance, moderate declines in maximal isometric force, but pronounced decreases in the rate of force development. Furthermore, the metabolic stress and muscle damage were minor; both sessions were generally well tolerated by well-functioning older adults without previous experience in resistance training.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/a-1408-4793DOI Listing
April 2021

'Fat but powerful' paradox: association of muscle power and adiposity markers with all-cause mortality in older adults from the EXERNET multicentre study.

Br J Sports Med 2021 Mar 16. Epub 2021 Mar 16.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain

Objectives: To assess the influence of muscle power and adiposity on all-cause mortality risk and to evaluate the 'fat but powerful' (F+P) (or 'fat but fit') paradox in older adults.

Methods: A total of 2563 older adults (65‒91 years old) from the EXERNET multicentre study were included. Adiposity (body mass index (BMI), waist circumference, body fat percentage (BF%) and fat index), allometric and relative power (sit-to-stand muscle power test) and various covariates (age, sex, hypertension, smoking status and walking and sitting times per day) were registered at baseline. All-cause mortality was recorded during a median follow-up of 8.9 years. Participants were classified into four groups: lean and powerful (L+P), F+P, lean but weak and fat and weak (F+W). Cox proportional hazard regression models and adjusted HRs were calculated.

Results: According to BMI and waist circumference, all-cause mortality risk was reduced in the F+P (HR=0.55 and 0.63, p=0.044 and 0.049, respectively) and L+P (HR=0.57 and 0.58, p=0.043 and 0.025, respectively) groups. According to BF%, all-cause mortality decreased in the L+P group (HR=0.53; p=0.021), and a trend for a reduction was reported in the F+P group (HR=0.57; p=0.060). According to fat index, a survival benefit was only noted in the L+P group (HR=0.50; p=0.049). Higher levels of relative power reduced all-cause mortality risk among older people (HR=0.63 and 0.53, p=0.006 and 0.011, respectively).

Conclusion: Powerful older people exhibited a reduced 9-year all-cause mortality regardless of BMI, waist circumference and BF%. Obesity according to fat index blunted the survival benefits of being powerful.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1136/bjsports-2020-103720DOI Listing
March 2021

Effects of Power-Oriented Resistance Training With Heavy vs. Light Loads on Muscle-Tendon Function in Older Adults: A Study Protocol for a Randomized Controlled Trial.

Front Physiol 2021 18;12:635094. Epub 2021 Feb 18.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

Background: Power-oriented resistance training (PRT) is one of the most effective exercise programs to counteract neuromuscular and physical function age-related declines. However, the optimal load that maximizes these outcomes or the load-specific adaptations induced on muscle power determinants remain to be better understood. Furthermore, to investigate whether these adaptations are potentially transferred to an untrained limb (i.e., cross-education phenomenon) could be especially relevant during limb-immobilization frequently observed in older people (e.g., after hip fracture).

Methods: At least 30 well-functioning older participants (>65 years) will participate in a within-person randomized controlled trial. After an 8-week control period, the effects of two 12-week PRT programs using light vs. heavy loads will be compared using an unilateral exercise model through three study arms (light-load PRT vs. non-exercise; heavy-load PRT vs. non-exercise; and light- vs. heavy- load PRT). Muscle-tendon function, muscle excitation and morphology and physical function will be evaluated to analyze the load-specific effects of PRT in older people. Additionally, the effects of PRT will be examined on a non-exercised contralateral limb.

Discussion: Tailored exercise programs are largely demanded given their potentially greater efficiency preventing age-related negative consequences, especially during limb-immobilization. This trial will provide evidence supporting the use of light- or heavy-load PRT on older adults depending on individual needs, improving decision making and exercise program efficacy.

Clinical Trial Registration: NCT03724461 registration data: October 30, 2018.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphys.2021.635094DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7935559PMC
February 2021

Sit-to-stand muscle power test: Comparison between estimated and force plate-derived mechanical power and their association with physical function in older adults.

Exp Gerontol 2021 03 21;145:111213. Epub 2020 Dec 21.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain; CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain. Electronic address:

Objectives: This study aimed i) to assess the assumptions made in the sit-to-stand (STS) muscle power test [body mass accelerated during the ascending phase (90% of total body mass), leg length (50% of total body height) and concentric phase (50% of total STS time)], ii) to compare force plate-derived (FPD) STS power values with those derived from the STS muscle power test; and iii) to analyze the relationships of both measurements with physical function.

Material And Methods: Fifty community-dwelling older adults (71.3 ± 4.4 years) participated in the present investigation. FPD STS power was calculated as the product of measured force (force platform) and velocity [difference between leg length (DXA scan) and chair height, divided by time (obtained from FPD data and video analysis)], and compared to estimated STS power using the STS muscle power test. Physical function was assessed by the timed-up-and-go (TUG) velocity, habitual gait speed (HGS) and maximal gait speed (MGS). Paired t-tests, Bland-Altman plots and regressions analyses were conducted.

Results: Body mass accelerated during the STS phase was 85.1 ± 3.8% (p < 0.05; compared to assumed 90%), leg length was 50.7 ± 1.3% of body height (p < 0.05; compared to 50%), and measured concentric time was 50.3 ± 4.6% of one STS repetition (p > 0.05; compared to assumed 50%). There were no significant differences between FPD and estimated STS power values (mean difference [95% CI] = 6.4 W [-68.5 to 81.6 W]; p = 0.251). Both FPD and estimated relative (i.e. normalized to body mass) STS power were significantly related to each other (r = 0.95 and ICC = 0.95; p < 0.05) and to MGS and TUG velocity after adjusting for age and sex (p < 0.05).

Conclusions: Estimated STS power was not different from FPD STS power and both measures were strongly related to each other and to maximal physical performance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exger.2020.111213DOI Listing
March 2021

Low relative mechanical power in older adults: An operational definition and algorithm for its application in the clinical setting.

Exp Gerontol 2020 12 27;142:111141. Epub 2020 Oct 27.

Department of Geriatrics, Hospital Virgen del Valle, Complejo Hospitalario de Toledo, Toledo, Spain; CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain. Electronic address:

Introduction: The assessment and treatment of low relative muscle power in older people has received little attention in the clinical setting when compared to sarcopenia. Our main goal was to assess the associations of low relative power and sarcopenia with other negative outcomes in older people.

Methods: The participants were 1189 subjects (54% women; 65-101 years old) from the Toledo Study for Healthy Aging. Probable sarcopenia was defined as having low handgrip strength, while confirmed sarcopenia also included low appendicular skeletal muscle index (assessed by dual energy X-ray absorptiometry) (EWGSOP2's definition). Low relative (i.e. normalized to body mass) muscle power was assessed with the 5-repetition sit-to-stand power test (which uses an equation that converts sit-to-stand performance into mechanical power) and diagnosed in those subjects in the lowest sex-specific tertile. Low usual gait speed (UGS), frailty (according to Fried's criteria and the Frailty Trait Scale), limitations in basic (BADL) and instrumental activities of daily living (IADL) and poor quality of life were also recorded.

Results: Age-adjusted logistic regression analyses demonstrated that low relative muscle power was associated with low UGS (odds ratio (OR) = 1.9 and 2.5), frailty (OR = 3.9 and 4.7) and poor quality of life (OR = 1.8 and 1.9) in older men and women, respectively, and with limitations in BADL (OR = 1.6) and IADL (OR = 3.8) in older women (all p < 0.05). Confirmed sarcopenia was only associated with low UGS (OR = 2.5) and frailty (OR = 5.0) in older men, and with limitations in IADL in older women (OR = 4.3) (all p < 0.05).

Conclusions: Low relative muscle power had a greater clinical relevance than low handgrip strength and confirmed sarcopenia among older people. An operational definition and algorithm for low relative muscle power case finding in daily clinical practice was presented.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exger.2020.111141DOI Listing
December 2020

Relation between leg extension power and 30-s sit-to-stand muscle power in older adults: validation and translation to functional performance.

Sci Rep 2020 10 1;10(1):16337. Epub 2020 Oct 1.

Geriatric Research Unit, Department of Geriatric and Palliative Medicine, Bispebjerg-Frederiksberg University Hospital, Copenhagen, Denmark.

This study aimed to assess the validity and functional relevance of a standardized procedure to assess lower limb muscle power by means of the 30-s sit-to-stand (STS) test when compared to leg extension power (LEP), traditional STS performance and handgrip strength. A total of 628 community-dwelling older subjects (60-93 years) from the Copenhagen Sarcopenia Study were included. Physical performance was assessed by the 30-s STS and 10-m maximal gait speed tests. Handgrip strength and LEP were recorded by a hand-held dynamometer and the Nottingham power rig, respectively. STS muscle power was calculated using the subjects' body mass and height, chair height and the number of repetitions completed in the 30-s STS test. We found a small albeit significant difference between LEP and unilateral STS power in older men (245.5 ± 88.8 vs. 223.4 ± 81.4 W; ES = 0.26; p < 0.05), but not in older women (135.9 ± 51.9 vs. 138.5 ± 49.6 W; ES = 0.05; p > 0.05). Notably, a large positive correlation was observed between both measures (r = 0.75; p < 0.001). Relative STS power was more strongly related with maximal gait speed than handgrip strength, repetition-based STS performance and relative LEP after adjusting for age (r = 0.53 vs 0.35-0.45; p < 0.05). In conclusion, STS power obtained from the 30-s STS test appeared to provide a valid measure of bilateral lower limb power and was more strongly related with physical performance than maximal handgrip strength, repetition-based STS performance and LEP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-020-73395-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7529789PMC
October 2020

Mechanical Characteristics of Heavy vs. Light Load Ballistic Resistance Training in Older Adults.

J Strength Cond Res 2020 Sep 16. Epub 2020 Sep 16.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

Rodriguez-Lopez, C, Alcazar, J, Sánchez-Martín, C, Ara, I, Csapo, R, and Alegre, LM. Mechanical characteristics in heavy vs. light load ballistic resistance training in older adults. J Strength Cond Res XX(X): 000-000, 2020-Although power-oriented resistance training (RT) is strongly recommended to counter age-related neuromuscular function declines, there is still controversy about which intensities of load should be used to elicit optimal training adaptations. Knowledge of the mechanical characteristics of power-oriented RT performed at different intensities might help to better understand the training stimulus that triggers load-dependent adaptations in older adults. Using a cross-over design, 15 well-functioning older volunteers (9 men and 6 women; 73.6 ± 3.8 years) completed 2 volume × load-matched ballistic RT sessions with heavy (HL: 6 × 6 × 80% 1-repetition maximum [1RM]) and light-load (LL: 6 × 12 × 40% 1RM) on a horizontal leg press exercise. Electromyographic (EMG) and mechanical variables (work, force, velocity, and power) as well as intraset neuromuscular fatigue (i.e., relative losses in force, velocity, and power) were analyzed. More concentric mechanical work was performed in the LL training session, compared with HL (36.2 ± 11.2%; p < 0.001). Despite the higher mean EMG activity of the quadriceps femoris muscle (13.2 ± 21.1%; p = 0.038) and greater concentric force (35.2 ± 7.6%; p < 0.001) during HL, higher concentric velocity (41.0 ± 12.7%, p < 0.001) and a trend toward higher concentric power (7.2 ± 18.9%, p = 0.075) were found for LL. Relative velocity losses were similar in both sessions (≈10%); however, relative force losses were only found in LL (7.4 ± 6.5%, p = 0.003). Considering the greater mechanical work performed and concentric power generated, ballistic RT using LL may, therefore, represent a stronger stimulus driving training adaptations as compared with volume × load-matched heavy-load training. Relative losses in force and power should be monitored in addition to velocity losses during ballistic RT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1519/JSC.0000000000003826DOI Listing
September 2020

Effects of velocity loss in the bench press exercise on strength gains, neuromuscular adaptations, and muscle hypertrophy.

Scand J Med Sci Sports 2020 Nov 2;30(11):2154-2166. Epub 2020 Aug 2.

Physical Performance & Sports Research Center, Department of Sports and Computers Sciences, Universidad Pablo de Olavide, Seville, Spain.

Objective: This study aimed to compare the effects of four velocity-based training (VBT) programs in bench press (BP) between a wide range of velocity loss (VL) thresholds-0% (VL0), 15% (VL15), 25% (VL25), and 50% (VL50)-on strength gains, neuromuscular adaptations, and muscle hypertrophy.

Methods: Sixty-four resistance-trained young men were randomly assigned into four groups (VL0, VL15, VL25, and VL50) that differed in the VL allowed in each set. Subjects followed a VBT program for 8-weeks using the BP exercise. Before and after the VBT program the following tests were performed: (a) cross-sectional area (CSA) measurements of pectoralis major (PM) muscle; (b) maximal isometric test; (c) progressive loading test; and (d) fatigue test.

Results: Significant group x time interactions were observed for CSA (P < .01) and peak root mean square in PM (peak RMS-PM, P < .05). VL50 showed significantly greater gains in CSA than VL0 (P < .05). Only the VL15 group showed significant increases in peak RMS-PM (P < .01). Moreover, only VL0 showed significant gains in the early rate of force development (RFD, P = .05), while VL25 and VL50 improved in the late RFD (P ≤ .01-.05). No significant group × time interactions were found for any of the dynamic strength variables analyzed, although all groups showed significant improvements in all these parameters.

Conclusion: Higher VL thresholds allowed for a greater volume load which maximized muscle hypertrophy, whereas lower VL thresholds evoked positive neuromuscular-related adaptations. No significant differences were found between groups for strength gains, despite the wide differences in the total volume accumulated by each group.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/sms.13775DOI Listing
November 2020

Impact of using the updated EWGSOP2 definition in diagnosing sarcopenia: A clinical perspective.

Arch Gerontol Geriatr 2020 Sep - Oct;90:104125. Epub 2020 May 23.

Department of Human Movement Sciences, @AgeAmsterdam, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam Movement Sciences, Amsterdam, the Netherlands; Department of Medicine and Aged Care, @AgeMelbourne, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia. Electronic address:

Background And Purpose: The revised European Working Group on Sarcopenia in Older People (EWGSOP2, version 2019) definition of sarcopenia differs with respect to the EWGSOP (version 2010) definition in applied criteria and their cut-off values. We aimed to investigate the impact of the new definition on sarcopenia prevalence in various populations of older adults.

Methods: Eight cohorts, including community-dwelling older adults, geriatric outpatients and patients admitted to acute and subacute inpatient wards were assessed on sarcopenia prevalence.

Results: A total of 2256 participants (56.4 % female) were included with a median age of the cohorts of 71.7-83.3 years. In males, sarcopenia prevalence was 31.9 % according to EWGSOP compared to 12.0 % according to EWGSOP2. In females, sarcopenia prevalence was 4.9 % and 6.1 % according to EWGSOP and EWGSOP2 respectively. Lower cut-off points for handgrip strength (27 kg versus 30 kg (males) and 16 kg versus 20 kg (females) for EWGSOP and EWGSOP2 respectively) resulted in the lower sarcopenia prevalence in males.

Conclusions: According to the EWGSOP2 definition, the prevalence of sarcopenia in males is significantly lower compared to the EWGSOP definition, whereas the prevalence among women is slightly higher. The lower cut-off points for handgrip strength result in fewer adults being diagnosed with sarcopenia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.archger.2020.104125DOI Listing
December 2020

Comparison of linear, hyperbolic and double-hyperbolic models to assess the force-velocity relationship in multi-joint exercises.

Eur J Sport Sci 2021 Mar 4;21(3):359-369. Epub 2020 May 4.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

This study assessed the validity of linear, hyperbolic and double-hyperbolic models to fit measured force-velocity (F-V) data in multi-joint exercises and the influence of muscle excitation on the F-V relationship. The force-joint angle and F-V relationships were assessed in 10 cross-training athletes and 14 recreationally resistance-trained subjects in the unilateral leg press (LP) and bilateral bench press (BP) exercises, respectively. A force plate and a linear encoder were installed to register external force and velocity, respectively. Muscle excitation was assessed by surface EMG recording of the quadriceps femoris, biceps femoris and gluteus maximus muscles during the unilateral LP. Linear, Hill's (hyperbolic) and Edman's (double-hyperbolic) equations were fitted to the measured F-V data and compared. Measured F-V data were best fitted by double-hyperbolic models in both exercises ( < 0.05). F-V data deviated from the rectangular hyperbola above a breakpoint located at 90% of measured isometric force () and from the linearity at ≤45% of (both  < 0.05). Hyperbolic equations overestimated values by 13 ± 11% and 6 ± 6% in the LP and BP, respectively ( < 0.05). No differences were found between muscle excitation levels below and above the breakpoint ( > 0.05). Large associations between variables obtained from linear and double-hyperbolic models were noted for , maximum muscle power, and velocity between 25% and 100% of ( = 0.70-0.99; all  < 0.05). The F-V relationship in multi-joint exercises was double-hyperbolic, which was unrelated with lower muscle excitation levels. However, linear models may be valid to assess , maximal muscle power and velocity between 25% and 100% of .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/17461391.2020.1753816DOI Listing
March 2021

Velocity Loss as a Critical Variable Determining the Adaptations to Strength Training.

Med Sci Sports Exerc 2020 08;52(8):1752-1762

Department of Physical Education and Sports, University of Seville, Seville, SPAIN.

Purpose: This study aimed to compare the effects of four resistance training (RT) programs with different velocity loss (VL) thresholds: 0% (VL0), 10% (VL10), 20% (VL20), and 40% (VL40) on sprint and jump performance, muscle strength, neuromuscular, muscle hypertrophy, and architectural adaptations.

Methods: Sixty-four young resistance-trained men were randomly assigned into four groups (VL0, VL10, VL20, and VL40) that differed in the VL allowed in each set. Subjects followed an RT program for 8 wk (two sessions per week) using the full-squat (SQ) exercise, with similar relative intensity (70%-85% 1-repetition maximum), number of sets (3), and interset recovery period (4 min). Before and after the RT program, the following tests were performed: 1) muscle hypertrophy and architecture of the vastus lateralis (VLA), 2) tensiomyography, 3) 20-m running sprint, 4) vertical jump, 5) maximal voluntary isometric contraction in SQ, 6) progressive loading test in SQ, and 7) fatigue test.

Results: No between-group differences existed for RT-induced gains in sprint, jump, and strength performance despite the differences in the total volume performed by each group. VL20 and VL40 showed significant increases (P < 0.001) in muscle hypertrophy (group-time interaction, P = 0.06). However, only VL40 exhibited a significant slowing (P < 0.001) of the delay time in the VLA muscle (group-time interaction, P = 0.05). Moreover, VL40 showed a significant decrease in the early rate of force development (P = 0.04).

Conclusions: Higher VL thresholds (i.e., VL20 and VL40) maximized hypertrophic adaptations, although an excessive VL during the set (i.e., VL40) may also induce negative neuromuscular adaptations. Therefore, moderate VL thresholds should be chosen to maximize strength adaptations and to prevent negative neuromuscular adaptations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1249/MSS.0000000000002295DOI Listing
August 2020

Age- and Sex-Specific Changes in Lower-Limb Muscle Power Throughout the Lifespan.

J Gerontol A Biol Sci Med Sci 2020 06;75(7):1369-1378

Geriatric Research Unit, Geriatric Department, Bispebjerg University Hospital, Copenhagen, Denmark.

Background: Our main goal was to evaluate the pattern and time course of changes in relative muscle power and its constituting components throughout the life span.

Methods: A total of 1,305 subjects (729 women and 576 men; aged 20-93 years) participating in the Copenhagen Sarcopenia Study took part. Body mass index (BMI), leg lean mass assessed by dual-energy X-ray absorptiometry (DXA), and leg extension muscle power (LEP) assessed by the Nottingham power rig were recorded. Relative muscle power (normalized to body mass) and specific muscle power (normalized to leg lean mass) were calculated. Segmented regression analyses were used to identify the onset and pattern of age-related changes in the recorded variables.

Results: Relative muscle power began to decline above the age of 40 in both women and men, with women showing an attenuation of the decline above 75 years. Relative muscle power decreased with age due to (i) the loss of absolute LEP after the fourth decade of life and (ii) the increase in BMI up to the age of 75 years in women and 65 years in men. The decline in absolute LEP was caused by a decline in specific LEP up to the age of 75 in women and 65 in men, above which the loss in relative leg lean mass also contributed.

Conclusions: Relative power decreased (i) above 40 years by the loss in absolute power (specific power only) and the increase in body mass, and (ii) above ~70 years by the loss in absolute power (both specific power and leg lean mass).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/gerona/glaa013DOI Listing
June 2020

The Copenhagen Sarcopenia Study: lean mass, strength, power, and physical function in a Danish cohort aged 20-93 years.

J Cachexia Sarcopenia Muscle 2019 12 16;10(6):1316-1329. Epub 2019 Aug 16.

Department of Clinical Physiology and Nuclear Medicine, Bispebjerg-Frederiksberg University Hospital, Copenhagen, Denmark.

Background: Despite no international consensus on the diagnostic criteria for sarcopenia, low lean mass, muscle strength, and physical function are important risk factors for disability, frailty, and mortality in older individuals, as well as in a wide range of patients with muscle loss. Here, we provide a population-based reference material of total and regional lean body mass, muscle strength/power parameters, and physical function in a healthy cohort of Danish men and women across the lifespan.

Methods: Volunteers aged 20-93 years from the Copenhagen City Heart Study were invited to establish a Danish reference material (Copenhagen Sarcopenia Study) on lean mass characteristics [appendicular lean mass (ALM), iDXA, GE Lunar], muscle function [handgrip strength (HGS), Jamar dynamometer and leg extension power (LEP), Nottingham Power Rig], and physical function [30 s sit-to-stand test (STS), 10-m maximal and habitual gait speed (GS)].

Results: A total of 1305 participants [729 women (age: 56.4 ± 18.9 years, height: 1.66 ± 0.01 m, body mass index: 24.6 ± 4.3 kg/m and 576 men, age: 57.0 ± 17.5 years, height: 1.80 ± 0.07 m, body mass index: 26.0 ± 3.9 kg/m ] completed all measurements and were included in the present analysis. Lean mass characteristics (TLM, ALM, and ALM/h ) decreased with increasing age in both men and women (P < 0.001). Men demonstrated larger absolute and relative total ALM and higher HGS and LEP compared with women at all age intervals (P < 0.001). HGS and LEP decreased progressively with age in both men and women (P < 0.01); 30 s STS performance, habitual GS, and maximal GS decreased at an accellerated rate of decline with increasing age in both men and women (P < 0.001). Habitual GS was reduced in men and women aged ≥70 years, while maximal GS was reduced from the age of ≥60 years compared with young adults (P < 0.001). Regardless of sex, 30 s STS was reduced from the age of ≥50 years compared with the young reference group (P < 0.001) CONCLUSIONS: While the power-based measurements (LEP and 30 s STS) started to decline already at age +50 years, less power-based parameters (GS and HGS) and lean mass characteristics (TLM, ALM, and ALM/h ) remained unaltered until after the age of +70 years. Notably, the cut-off thresholds derived in the present study differed from earlier reference data, which underlines the importance of obtaining updated and local reference materials.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/jcsm.12477DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6903448PMC
December 2019

On the Shape of the Force-Velocity Relationship in Skeletal Muscles: The Linear, the Hyperbolic, and the Double-Hyperbolic.

Front Physiol 2019 19;10:769. Epub 2019 Jun 19.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

The shape of the force-velocity (F-V) relationship has important implications for different aspects of muscle physiology, such as muscle efficiency and fatigue, the understanding of the pathophysiology of several myopathies or the mechanisms of muscle contraction , and may be of relevance for other fields, such as the development of robotics and prosthetic applications featuring natural muscle-like properties. However, different opinions regarding the shape of the F-V relationship and the underlying mechanisms exist in the literature. In this review, we summarize relevant evidence on the shape of the F-V relationship obtained over the last century. Studies performed at multiple scales ranging from the sarcomere to the organism level have described the concentric F-V relationship as linear, hyperbolic or double-hyperbolic. While the F-V relationship has most frequently been described as a rectangular hyperbola, a large number of studies have found deviations from the hyperbolic function at both ends of the F-V relation. Indeed, current evidence suggests that the F-V relation in skeletal muscles follows a double-hyperbolic pattern, with a breakpoint located at very high forces/low velocities, which may be a direct consequence of the kinetic properties of myofilament cross-bridge formation. Deviations at low forces/high velocities, by contrast, may be related to a recently discovered, calcium-independent regulatory mechanism of muscle contraction, which may also explain the low metabolic cost of very fast muscle shortening contractions. Controversial results have also been reported regarding the eccentric F-V relationship, with studies in prepared muscle specimens suggesting that maximum eccentric force is substantially greater than isometric force, whereas studies in humans show only a modest increase, no change, or even a decrease in force in lengthening contractions. This review discusses possible reasons reported in the literature for these discrepant findings, including the testing procedures (familiarization, pre-load condition, and temperature) and a potential neural inhibition at higher lengthening velocities. Finally, some unresolved questions and recommendations for F-V testing in humans are reported at the end of this document.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphys.2019.00769DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6593051PMC
June 2019

Effects of concurrent exercise training on muscle dysfunction and systemic oxidative stress in older people with COPD.

Scand J Med Sci Sports 2019 Oct 24;29(10):1591-1603. Epub 2019 Jun 24.

CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain.

Oxidative stress is associated with disease severity and limb muscle dysfunction in COPD. Our main goal was to assess the effects of exercise training on systemic oxidative stress and limb muscle dysfunction in older people with COPD. Twenty-nine outpatients with COPD (66-90 years) were randomly assigned to a 12-week exercise training (ET; high-intensity interval training (HIIT) plus power training) or a control (CT; usual care) group. We evaluated mid-thigh muscle cross-sectional area (CSA; computed tomography); vastus lateralis (VL) muscle thickness, pennation angle, and fascicle length (ultrasonography); peak VO uptake (VO ) and work rate (W ) (incremental cardiopulmonary exercise test); rate of force development (RFD); maximal muscle power (P ; force-velocity testing); systemic oxidative stress (plasma protein carbonylation); and physical performance and quality of life. ET subjects experienced changes in mid-thigh muscle CSA (+4%), VL muscle thickness (+11%) and pennation angle (+19%), VO (+14%), W (+37%), RFD (+32% to 65%), P (+38% to 51%), sit-to-stand time (-24%), and self-reported health status (+20%) (all P < 0.05). No changes were noted in the CT group (P > 0.05). Protein carbonylation decreased among ET subjects (-27%; P < 0.05), but not in the CT group (P > 0.05). Changes in protein carbonylation were associated with changes in muscle size and pennation angle (r = -0.44 to -0.57), exercise capacity (r = -0.46), muscle strength (r = -0.45), and sit-to-stand performance (r = 0.60) (all P < 0.05). The combination of HIIT and power training improved systemic oxidative stress and limb muscle dysfunction in older people with COPD. Changes in oxidative stress were associated with exercise-induced structural and functional adaptations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/sms.13494DOI Listing
October 2019

The Effect of the Stretch-Shortening Cycle in the Force-Velocity Relationship and Its Association With Physical Function in Older Adults With COPD.

Front Physiol 2019 26;10:316. Epub 2019 Mar 26.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

This study aimed to evaluate the effect of the stretch-shortening cycle (SSC) on different portions of the force-velocity (F-V) relationship in older adults with and without chronic obstructive pulmonary disease (COPD), and to assess its association with physical function. The participants were 26 older adults with COPD (79 ± 7 years old; FEV = 53 ± 36% of predicted) and 10 physically active non-COPD (77 ± 4 years old) older adults. The F-V relationship was evaluated in the leg press exercise during a purely concentric muscle action and compared with that following an eccentric muscle action at 10% intervals of maximal unloaded shortening velocity (V). Vastus lateralis (VL) muscle thickness, pennation angle (PA), and fascicle length (FL) were assessed by ultrasound. Habitual gait speed was measured over a 4-m distance. COPD subjects exhibited lower physical function and concentric maximal muscle power (P) values compared with the non-COPD group (both 0.05). The SSC increased force and power values among COPD participants at 0-100 and 1-100% of V, respectively, while the same was observed among non-COPD participants only at 40-90 and 30-90% of V, respectively (all < 0.05). The SSC induced greater improvements in force, but not power, among COPD compared with non-COPD subjects between 50 and 70% of V (all < 0.05). Thus, between-group differences in muscle power were not statistically significant after the inclusion of the SSC ( > 0.05). The SSC-induced potentiation at 50-100% of V was negatively associated with physical function ( = -0.40-0.50), while that observed at 80-100% of V was negatively associated with VL muscle thickness and PA ( = -0.43-0.52) (all < 0.05). In conclusion, older adults with COPD showed a higher SSC-induced potentiation compared with non-COPD subjects, which eliminated between-group differences in muscle power when performing SSC muscle actions. The SSC-induced potentiation was associated with lower physical function, VL muscle thickness, and VL PA values. The SSC-induced potentiation may help as a compensatory mechanism in those older subjects with a decreased ability to produce force/power during purely concentric muscle actions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fphys.2019.00316DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6443992PMC
March 2019

Effect of a short multicomponent exercise intervention focused on muscle power in frail and pre frail elderly: A pilot trial.

Exp Gerontol 2019 01 4;115:114-121. Epub 2018 Dec 4.

CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain; Hospital Virgen del Valle, Complejo Hospitalario de Toledo, Toledo, Spain. Electronic address:

Objectives: The aim was to establish whether a short supervised facility-based exercise program improved frailty, physical function and performance in comparison with usual care treatment.

Methods: This was a quasi-experimental, non-randomized controlled intervention study in frail (2.75 ± 1.25 Frailty Phenotype criteria) older adults (range:77.2-95.8 years). The exercise (EX) group (n = 11) performed concurrent training (power training + high-intensity interval training, HIIT) twice weekly for 6 weeks while the control (CT) group (n = 9) followed usual care.

Results: The exercise intervention improved frailty status in 64% of the subjects improving Frailty Phenotype by 1.6 points (95%CI 0.8-2.5, p < 0.05), and increasing SPPB score by 3.2 points (95%CI: 2.4-4.0, Cohen's d = 2.0, p < 0.05), muscle power by 47% (95%CI: 7-87%, Cohen's d = 0.5, p < 0.05), muscle strength by 34%(95%CI: 7-60, Cohen's d = 0.6, p < 0.05) and the aerobic capacity by 19% (6 minute walking test +45 m, 95%CI: 7-83, Cohen's d = 0.7, p = 0.054). The CT did not experience any significant changes in frailty status, physical function or performance.

Conclusions: A short concurrent exercise program of muscle power and walking-based HIIT training is a feasible and safe method to increase physical performance and improve function and frailty in elder (pre)frail patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exger.2018.11.022DOI Listing
January 2019

The sit-to-stand muscle power test: An easy, inexpensive and portable procedure to assess muscle power in older people.

Exp Gerontol 2018 10 1;112:38-43. Epub 2018 Sep 1.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain; CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain. Electronic address:

Introduction: Skeletal muscle power has been demonstrated to be a stronger predictor of functional limitations than any other physical capability. However, no validated alternatives exist to the usually expensive instruments and/or time-consuming methods to evaluate muscle power in older populations. Our aim was to validate an easily applicable procedure to assess muscle power in large cohort studies and the clinical setting and to assess its association with other age-related outcomes.

Methods: Forty community dwelling older adults (70-87 years) and 1804 older subjects (67-101 years) participating in the Toledo Study for Healthy Aging were included in this investigation. Sit-to-stand (STS) velocity and muscle power were calculated using the subject's body mass and height, chair height and the time needed to complete five STS repetitions, and compared with those obtained in the leg press exercise using a linear position transducer. In addition, STS performance, physical (gait speed) and cognitive function, sarcopenia (skeletal muscle index (SMI)) and health-related quality of life (HRQoL) were recorded to assess the association with the STS muscle power values.

Results: No significant differences were found between STS velocity and power values and those obtained from the leg press force-velocity measurements (mean difference ± 95% CI = 0.02 ± 0.05 m·s and 6.9 ± 29.8 W, respectively) (both p > 0.05). STS muscle power was strongly associated with maximal muscle power registered in the leg press exercise (r = 0.72; p < 0.001). In addition, cognitive function and SMI, and physical function, were better associated with absolute and relative STS muscle power, respectively, than STS time values after adjusting by different covariates. In contrast, STS time was slightly more associated with HRQoL than STS muscle power measures.

Conclusion: The STS muscle power test proved to be a valid, and in general, a more clinically relevant tool to assess functional trajectory in older people compared to traditional STS time values. The low time, space and material requirements of the STS muscle power test, make this test an excellent choice for its application in large cohort studies and the clinical setting.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exger.2018.08.006DOI Listing
October 2018

The double-hyperbolic force-velocity relationship in humans.

Acta Physiol (Oxf) 2019 08 13;226(4):e13165. Epub 2018 Aug 13.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/apha.13165DOI Listing
August 2019

Force-velocity profiling in older adults: An adequate tool for the management of functional trajectories with aging.

Exp Gerontol 2018 07 20;108:1-6. Epub 2018 Mar 20.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain; CIBER of Frailty and Healthy Aging (CIBERFES), Madrid, Spain. Electronic address:

Introduction: The actual mechanisms leading to a reduced muscle power and functional ability in older adults are poorly understood. We investigated the association between different force-velocity (F-V) profiles and impaired muscle power, physical and cognitive function, frailty, and health-related quality of life (HRQoL) in older people.

Methods: Physical function (habitual gait speed, timed up-and-go test, sit-to-stand and stair-climbing ability), cognitive function, HRQoL and frailty were evaluated in 31 older subjects (70-85 years). The F-V relationship and maximal muscle power (P) were assessed in the leg press exercise. The skeletal muscle index (SMI) and fat index, moderate-to-vigorous physical activity (MVPA) and sedentary time were obtained from DXA scans and accelerometry, respectively.

Results: While some subjects showed a force deficit (F), others presented a velocity deficit (V), both leading to an impaired muscle power [Effect size (ES) = 1.30-1.44], and to a likely-very likely moderate harmful effect in their physical and cognitive function, HRQoL and frailty levels (except the V group for cognitive function) [ES = 0.76-1.05]. Leg muscle mass and specific force were similarly associated with force at P, while MVPA but not sedentary time was related to fat index, force at P, and power values (all p < 0.05). A trend was found for the negative association between fat index and relative P (p = 0.075).

Conclusion: Older subjects exhibited different mechanisms (force vs. velocity deficits) leading to impaired muscle power. Both deficits were associated with a lower physical function and quality of life, and a higher frailty, whereas only a force deficit was associated with a lower cognitive function. Interventions aimed at reversing age- and/or disuse-related impairments of muscle power might evaluate the specific responsible mechanism and act accordingly.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exger.2018.03.015DOI Listing
July 2018

Validation of Field Methods to Assess Body Fat Percentage in Elite Youth Soccer Players.

Int J Sports Med 2018 May 21;39(5):349-354. Epub 2018 Mar 21.

Football performance & science department, Aspire Academy, Doha, Qatar.

This study determined the most effective field method for quantifying body fat percentage in male elite youth soccer players and developed prediction equations based on anthropometric variables. Forty-four male elite-standard youth soccer players aged 16.3-18.0 years underwent body fat percentage assessments, including bioelectrical impedance analysis and the calculation of various skinfold-based prediction equations. Dual X-ray absorptiometry provided a criterion measure of body fat percentage. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses were used to develop soccer-specific prediction equations. The equations from Sarria et al. (1998) and Durnin & Rahaman (1967) reached very large correlations and the lowest biases, and they reached neither the practically worthwhile difference nor the substantial difference between methods. The new youth soccer-specific skinfold equation included a combination of triceps and supraspinale skinfolds. None of the practical methods compared in this study are adequate for estimating body fat percentage in male elite youth soccer players, except for the equations from Sarria et al. (1998) and Durnin & Rahaman (1967). The new youth soccer-specific equation calculated in this investigation is the only field method specifically developed and validated in elite male players, and it shows potentially good predictive power.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0044-101145DOI Listing
May 2018

Skeletal Muscle Power Measurement in Older People: A Systematic Review of Testing Protocols and Adverse Events.

J Gerontol A Biol Sci Med Sci 2018 06;73(7):914-924

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

Background: Muscle power has been proposed to be the primary therapeutic target for resistance training interventions aimed at enhancing physical function in older adults. However, no recommendations exist on ideal testing protocols to assess muscle power in older adults, and the safety of this procedure has not been adequately evaluated in the literature.

Methods: A systematic review was conducted to identify studies evaluating muscle power exerted by older people in resistance exercises through May 2017. Information from muscle power testing protocols regarding familiarization, warm-up, measuring instrument, exercise, intensity, volume, rest intervals, data collection, and analysis was collected, as well as that regarding adverse events. Reporting bias was evaluated according to the recommendations given by the Cochrane Collaboration group.

Results: From 65 studies that met inclusion criteria, 3,484 older subjects and 11,841 muscle power tests distributed in 6,105 testing sessions were identified. A full description of the different muscle power testing protocols was conducted. In addition, a risk of adverse events of 0.15%-0.69% (one adverse event every 144-658 muscle power tests) was found. However, adverse events were poorly reported, with most of the studies showing a high risk of reporting bias.

Conclusions: Major discrepancies were found in muscle power testing protocols among studies. This might limit consensus on designing optimal training programs to improve muscle power and physical function in older adults, and understanding the main mechanisms involved in the age-related loss of muscle power. Finally, muscle power testing was found to be safe in older people with a broad range of health and functional states.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/gerona/glx216DOI Listing
June 2018

The Force-Velocity Relationship in Older People: Reliability and Validity of a Systematic Procedure.

Int J Sports Med 2017 Dec 10;38(14):1097-1104. Epub 2017 Nov 10.

GENUD Toledo Research Group, Universidad de Castilla-La Mancha, Toledo, Spain.

This study compared the reliability and validity of different protocols evaluating the force-velocity (F-V) relationship and muscle power in older adults. Thirty-one older men and women (75.8±4.7 years) underwent two F-V tests by collecting the mean and peak force and velocity data exerted against increasing loads until one repetition maximum (1RM) was achieved in the leg press exercise. Two attempts per load were performed, with a third attempt when F-V points deviated from the linear F-V regression equation. Then, the subjects performed 2×3 repetitions at 60% 1RM to compare purely concentric and eccentric-concentric repetitions. The Short Physical Performance Battery was conducted to assess the validity of the different protocols. Significant differences were found in maximal power (Pmax) between mean and peak values and between protocols differing in the number of attempts per load (p<0.01). Registering mean values, a third attempt, and multiple loads (>3), was significantly more reliable (Pmax: CV=2.6%; ICC=0.99) than the other alternatives. Mean values were also observed to be more associated with physical function than peak values (R2=0.34 and 0.15, respectively; p<0.05). No significant differences were observed between concentric and eccentric-concentric repetitions. Thus, collecting mean force and velocity values against multiple loads, while monitoring the linearity of the F-V relationship, seemed to be the more adequate procedure to assess the F-V profile and muscle power in older adults.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1055/s-0043-119880DOI Listing
December 2017

Short- and Long-Term Effects of Concurrent Strength and HIIT Training in Octogenarians with COPD.

J Aging Phys Act 2017 01 24;25(1):105-115. Epub 2016 Aug 24.

To investigate the short- and long-term effects of concurrent strength and high-intensity interval training (HIIT) on octogenarian COPD patients, nine males (age = 84.2 ± 2.8 years, BMI = 29.3 ± 2.3) with low to severe COPD levels (2.1 ± 1.5 BODE index) underwent a supervised 9-week strength and HIIT exercise program. Training had a significant (p < .05) impact on senior fitness test scores (23-45%), 30-m walking speed (from 1.29 ± 0.29-1.62 ± 0.33 m/s), leg and chest press 1RM (38% and 45% respectively), maximal isometric strength (30-35%), and 6-min walking test (from 286.1 ± 107.2-396.2 ± 106.5 m), and tended to increase predicted forced vital capacity by 14% (p = .07). One year after the intervention all training-induced gains returned to their preintervention values except for the chest press 1RM (p <.05). Short-term concurrent strength and HIIT training increases physical fitness in the oldest-old COPD patients, and has potential long-term benefits.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1123/japa.2015-0307DOI Listing
January 2017

Associations between obesity, physical fitness, and urinary incontinence in non-institutionalized postmenopausal women: The elderly EXERNET multi-center study.

Maturitas 2015 Oct 17;82(2):208-14. Epub 2015 Jul 17.

Growth, Exercise, Nutrition and Development (GENUD) Toledo Research Group, University of Castilla-La Mancha, Toledo, Spain. Electronic address:

Objectives: To investigate the associations between body composition, fitness level, and urinary incontinence (UI) in 471 non-institutionalized women ≥ 65 years of age.

Study Design: Cross-sectional study.

Method: UI was assessed using the International Consultation on Incontinence Questionnaire Short-Form and a specific severity UI item. Anthropometric measurements were obtained using standardized techniques and equipment. Body fat percentage (BF%) was measured by bioelectrical impedance. Physical fitness (PF) was evaluated by a set of 8 tests and a fitness index (FI) was calculated. Active and sedentary behaviors were recorded by standardized questionnaires.

Results: UI was reported in 28.5% of the participants. Women with UI showed higher values of body mass index (BMI), BF% and waist circumference (WC) (all p<0.05) compared to urinary continent women, whereas there was a lower fitness index (FI) level in women with UI (p=0.08). Among all fitness capacities, upper body flexibility showed the closest relationship with UI. UI risk increased by 87.0% [95% confidence intervals (1.01-3.17)] in obese women compared to the normal group, according to the BF% while no significant results were found when PF, WC and BMI were included in the model. Mean sitting and walking time per day were 4.3±1.4 and 1.8±0.9 h/d, respectively.

Conclusion: UI was associated with an excess of fat mass and poor PF, especially upper-body flexibility.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.maturitas.2015.07.008DOI Listing
October 2015
-->