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1.
Article in English | MEDLINE | ID: mdl-37681791

ABSTRACT

Sarcopenia is the loss of muscle mass and function from aging, inactivity, or disuse. It is a comorbidity to numerous conditions that exacerbates their severity and adversely impacts activities of daily living. While sarcopenia now receives more attention from the medical community, people with sarcopenia as a comorbidity nevertheless still sometimes receives less attention than other presenting diseases or conditions. Inevitable doctors' visits or hospital stays for those with sarcopenia as a comorbidity have far higher healthcare costs than those without this condition, which imposes a greater financial burden on the medical insurance and healthcare industries. This review offers information and guidance on this topic. Treatments for sarcopenia include dietary, exercise, and pharmacological interventions. Yet, the latter treatment is only recommended in extreme cases as it may evoke numerous side effects and has little support in the scientific literature. Currently, a more holistic approach, with an emphasis on lifestyle modification, to reduce the likelihood of sarcopenia is examined. The current review discusses dietary and exercise interventions to limit the occurrence and severity of sarcopenia. References cited in this review conformed to the Declaration of Helsinki requirements for the use of human research subjects. Most of this review's references (~97%) came from a PubMed search that spanned from 1997 to 2023. Search terms included "sarcopenia" OR "muscle wasting" OR "geriatrics"; OR "ageing"; and AND "diet" OR "exercise". In addition, papers relevant or supportive of the topic as well as those considered seminal were included in the review. Over 96% of the references were peer-reviewed articles.


Subject(s)
Activities of Daily Living , Sarcopenia , Humans , Diet , Sarcopenia/prevention & control , Aging , Muscular Atrophy
2.
J Funct Morphol Kinesiol ; 8(3)2023 Jun 24.
Article in English | MEDLINE | ID: mdl-37489302

ABSTRACT

Field lacrosse requires sudden directional changes and rapid acceleration/deceleration. The capacity to perform these skills is dependent on explosive muscle force production. Limited research exists on the potential of sprint interval training (SIT) to impact explosive muscle force production in field lacrosse players. The purpose of this study is to examine SIT, concurrent to field-lacrosse-specific training, on the rate of torque development (RTD), contractile impulse, and muscle function in female high school field lacrosse players (n = 12; 16 ± 1 yrs.). SIT was performed three times per week, concurrent to field-lacrosse-specific training, for 12 weeks. Right lower-limb muscle performance was assessed pre-, mid-, and post-SIT training via isometric and isokinetic concentric knee extensor contractions. Outcomes included RTD (Nm·s-1), contractile impulse (Nm·s), and peak torque (Nm). RTD for the first 50 ms of contraction improved by 42% by midseason and remained elevated at postseason (p = 0.004, effect size (ES) = -577.3 to 66.5). Contractile impulse demonstrated a training effect across 0-50 ms (42%, p = 0.004, ES = -1.4 to 0.4), 0-100 ms (33%, p = 0.018, ES = 3.1 to 0.9), and 0-200 ms (22%, p = 0.031, ES = -7.8 to 1.6). Isometric (0 rad·s-1) and concentric (3.1 rad·s-1) strength increased by 20% (p = 0.002, ES = -60.8 to -20.8) and 9% (p = 0.038, ES = -18.2 to 0.0) from SIT and field-lacrosse-specific training, respectively (p < 0.05). SIT, concurrent to field-lacrosse-specific training, enhanced lower-limb skeletal muscle performance, which may enable greater sport-specific gains.

3.
Aerosp Med Hum Perform ; 94(12): 923-933, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-38176031

ABSTRACT

BACKGROUND: Bone mineral density (BMD) is a measure of skeletal health that may foretell disorders like osteoporosis.METHODS: To reduce bone losses on Earth, treatments include exercise, diet, and drugs. Each impact osteoblast and osteoclast activity dictates skeletal remodeling and subsequent BMD changes. BMD loss is a concern during spaceflight. For astronauts, low BMD undermines in-flight tasks and compromises their postflight health.RESULTS: While bisphosphonates exhibited promise as an in-flight bone loss treatment, study results are mixed, and this class of drugs has numerous side-effects. While the role antiresorptive agents play in reducing BMD loss is discussed, this review focuses on exercise-induced strains and nutrition, two in-flight treatments without bisphosphonates' side-effects.DISCUSSION: Evidence supports in-flight exercise and a healthy diet with vitamin D and Ca+2 supplementation to limit BMD loss. This review suggests how exercise and nutrition may limit BMD loss during spaceflight. Also discussed is an in-flight version of the inertial exercise trainer (IET; Impulse Technologies, Knoxville TN). By imparting high bone-strain magnitudes, rates, and frequencies with less mass, footprint, and power needs than other forms of in-flight resistance exercise hardware, the IET warrants inquiry for use aboard future long-term spaceflights.Caruso J, Patel N, Wellwood J, Bollinger L. Impact of exercise-induced strains and nutrition on bone mineral density in spaceflight and on the ground. Aerosp Med Hum Perform. 2023; 94(12):923-933.


Subject(s)
Bone Density , Exercise , Nutritional Status , Space Flight , Humans , Astronauts , Bone and Bones , Diphosphonates/pharmacology , Exercise/adverse effects
4.
J Strength Cond Res ; 35(4): 931-940, 2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33629973

ABSTRACT

ABSTRACT: O'Brien, IT, Kozerski, AE, Gray, WD, Chen, L, Vargas, LJ, McEnroe, CB, Vanhoover, AC, King, KM, Pantalos, GM, and Caruso, JF. Use of gloves to examine intermittent palm cooling's impact on rowing ergometry. J Strength Cond Res 35(4): 931-940, 2021-The aim of this study was to examine the use of gloves on intermittent palm cooling's impact on rowing ergometry workouts. Our methods had subjects (n = 34) complete 3 rowing ergometer workouts of up to 8 2-minute stages separated by 45- or 60-second rests. They were randomized to one of the following treatments per workout: no palm cooling (NoPC), intermittent palm cooling as they rowed (PCex), or intermittent palm cooling as they rowed and post-exercise (PCex&post). Palm cooling entailed intermittent cold (initial temperature: 8.1° C) application and totaled 10 (PCex) and 20 (PCex&post) minutes, respectively. Workouts began with 8 minutes of rest after which pre-exercise data were obtained, followed by a ten-minute warm-up and the workout, and 20 minutes of post-exercise recovery. Numerous physiological and performance variables were collected before, during, and after workouts, and each was analyzed with either a two- or three-way analysis of variance. Our results include, with a 0.05 alpha and a simple effects post hoc, the distance rowed analysis produced a significant workout effect with PCex, PCex&post > NoPC. There were also significant interworkout differences for heart rate (HR) (NoPC > PCex) and blood lactate concentration (NoPC > PCex, PCex&post). We conclude that lower HRs and blood lactate concentrations from intermittent cooling caused subjects to experience less fatigue during those workouts and enabled more work to be performed. Continued research should identify optimal cooling characteristics to expedite body heat removal. Practical applications suggest that intermittent palm cooling administered with gloves enhance performance by abating physiological markers of fatigue.


Subject(s)
Ergometry , Gloves, Protective , Water Sports , Cold Temperature , Hand , Heart Rate
5.
J Strength Cond Res ; 35(2): 391-403, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33278269

ABSTRACT

ABSTRACT: Gray, WD, Jett, DM, Cocco, AR, Vanhoover, AC, Colborn, CE, Pantalos, GM, Stumbo, J, Quesada, PM, and Caruso, JF. Ergogenic and physiological outcomes derived from a novel skin cooling device. J Strength Cond Res 35(2): 391-403, 2021-Our study's purpose assessed a cooling headband's ergogenic and physiological impacts. Subjects (15 women and 13 men) completed six visits; the final 3 entailed rowing workouts with the following treatment conditions: no head cooling (NoHC), intermittent head cooling during exercise (HCex), and intermittent head cooling during exercise and post-exercise recovery (HCex&post). Data collection occurred at the following times (a) pre-exercise and post-warm-up, (b) between stages of up to eight 2-minute bouts, and (c) at 5, 10, 15, and 20 minutes post-exercise. In addition to distance rowed, thermal, cardiovascular, perceptual, and metabolic measurements were obtained. Results included a small yet significant intertreatment difference (HCex, HCex&post > NoHC) for distance rowed. Our cardiovascular and metabolic indices exhibited sex and time differences but likely did not contribute to the ergogenic effect. Yet, left hand temperatures (LHT) exhibited significant 2-way and 3-way interactions that were the likely source of the ergogenic effect. Auditory canal temperature (AUDT) results suggest the head is sensitive to heat increases, yet LHT data show headband use evoked significantly greater temperature increases at the hand's palmar surface, indicative of heat transfer. We conclude, and our practical applications suggest, the headband's ergogenic effect was manifested by cold-induced vasodilation at the hand's palmar surface, rather than heat losses through the head.


Subject(s)
Performance-Enhancing Substances , Body Temperature , Body Temperature Regulation , Cold Temperature , Female , Hot Temperature , Humans , Male , Skin Temperature
6.
Nutrients ; 12(8)2020 Aug 11.
Article in English | MEDLINE | ID: mdl-32796546

ABSTRACT

Immune system dysregulation is among the many adverse effects incurred by astronauts during space flights. Omega-3 fatty acids, ß-alanine, and carnosine are among the many nutrients that contribute to immune system health. For space flight, crewmembers are prescribed a diet with a macronutrient composition of 55% carbohydrate, 30% fat, and 15% protein. To quantify omega-3 fatty acid, ß-alanine and carnosine intakes from such a diet, and to examine each nutrient's impact on exercise performance, 21 participants adhered to the aforementioned macronutrient ratio for 14 days which was immediately followed by a workout performed on gravity-independent resistive exercise hardware. Results included daily omega-3 fatty acid intakes below the suggested dietary intake. Daily omega-3 fatty acid, ß-alanine and carnosine intakes each correlated with non-significant amounts of variance from the workout's volume of work. Given the nutritional requirements to maintain immune system function and the demands of in-flight exercise countermeasures for missions of increasingly longer durations current results, in combination with previously published works, imply in-flight supplementation may be a prudent approach to help address the physiological and mental challenges incurred by astronauts on future space flights.


Subject(s)
Deficiency Diseases/physiopathology , Diet/adverse effects , Exercise/physiology , Resistance Training/methods , Space Flight , Adult , Astronauts , Carnosine/analysis , Cross-Over Studies , Deficiency Diseases/etiology , Diet/methods , Diet Surveys , Fatty Acids, Omega-3/analysis , Female , Humans , Immune System/drug effects , Male , Nutritional Requirements , Weightlessness Countermeasures , Weightlessness Simulation , beta-Alanine/analysis
7.
Bone ; 128: 115049, 2019 11.
Article in English | MEDLINE | ID: mdl-31454536

ABSTRACT

Thirty workouts on a gravity-independent device (Impulse Training Systems, Newnan GA) evoked significant calcaneal bone mineral content (BMC, +29%) and density (BMD, +33%) gains. High speeds and impact loads were produced per repetition. We examined exercise performance variables from the 30-workout intervention to identify correlates to delta (∆) calcaneal BMC and BMD variance. Workouts included hip extension and seated calf press exercises done with subject's left legs. ∆ values were obtained from the first and 12th workouts for the hip extension movement, and for the first and 24th workouts for the seated calf press exercise. Per exercise the following variables were quantified: peak force (∆PF), peak acceleration (∆PA), impulse (∆I), and dwell times (∆DT). Dwell times are the elapsed time between the end of the eccentric phase, and the start of the next repetition's concentric phase. Pearson Coefficients assessed correlations between performance and criterion variables. With hip extension ∆DT calculated with data from the first and 12th workouts, there were significant correlations with calcaneal ∆BMC (r = -0.64) and ∆BMD (r = -0.63). With seated calf press ∆DT derived as the difference from the first and 24th workouts, there was a significant correlation with calcaneal ∆BMC (r = -0.48), but only a trend (r = -0.45) with ∆BMD as the criterion. No other variables correlated with significant amounts of calcaneal ∆BMC and ∆BMD variance. Negative correlations infer shorter dwell times evoked greater gains. The gravity-independent device warrants continued inquiry to treat and abate calcaneal losses.


Subject(s)
Calcaneus/metabolism , Osteogenesis/physiology , Absorptiometry, Photon , Adult , Body Mass Index , Bone Density/physiology , Exercise/physiology , Female , Gravitation , Humans , Male , Resistance Training , Young Adult
8.
J Strength Cond Res ; 33(6): 1480-1487, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30946264

ABSTRACT

Chen, L, Davison, SW, Selimovic, EA, Mueller, RE, Beatty, SR, Carter, KA, Parmar, PJ, Symons, TB, Pantalos, GM, and Caruso, JF. Load-power relationships for high-speed knee extension exercise. J Strength Cond Res 33(6): 1480-1487, 2019-Seventy subjects did 4 knee extensor workouts with their left legs to assess load-power relationships produced on a high-speed trainer (HST; Newnan, GA, USA). Each workout is composed of 4 sets done on the HST at a different load (1, 4.4, 6.7, 9 kg). A Latin Squares Design determined load sequence per workout. Average power (AP) and peak power (PP) and those same values normalized to body mass (BM) and fat-free mass (AP/BM, PP/BM, AP/FFM, PP/FFM) were each analyzed with 2 (gender) × 4 (load) analysis of variances, with repeated measures for load. We assessed relationships between normalized loads and AP and PP values with correlation coefficients. Average power results revealed a significant interaction, with men > women at 9 kg. Peak power/body mass also yielded an interaction, with women > men at 6.7 and 9 kg. Average power/fat-free mass and PP/FFM each produced interactions, with women > men at 4.4, 6.7, and 9 kg. Correlation coefficients showed significant (r = 0.80-0.82) relationships between normalized loads and AP and PP values. In conclusion, the very low inertial resistance to initiate each repetition on this novel device may in part explain our PP/BM, AP/FFM, PP/FFM results, in which higher values were achieved by women. Our practical applications imply that the low inertial resistance for HST repetitions negates male size and strength advantages typically seen when power is measured.


Subject(s)
Exercise Test/instrumentation , Muscle Strength , Quadriceps Muscle/physiology , Adolescent , Body Weight , Female , Humans , Knee Joint , Male , Resistance Training/instrumentation , Young Adult
9.
Int J Sports Med ; 39(10): 791-801, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30025418

ABSTRACT

While bones and muscles adapt to mechanical loading, it appears that very specific types of stimuli must be applied to achieve osteogenesis. Our study assessed musculoskeletal outcomes to 30 training sessions on an Inertial Exercise Trainer (Newnan, GA). Subjects (n=13) performed workouts with their left leg, while their right served as an untreated control. Workouts entailed three 60-s sets each of knee extension, hip extension and calf press exercises, separated by 90-s rests. Before and after the 30 training sessions, subjects underwent strength tests (knee and ankle extensors of both legs), DEXA scans (hip, knee and ankles of both legs), and blood draws. After 30 training sessions 2×2 ANOVAs showed left leg peak torques rose significantly. 2×2 ANCOVAs, with bone scan area as a covariate, showed significant left leg calcaneal bone mineral content (+29%) and density (+33%) increases after 30 training sessions. A significant decline in C-terminal telopeptides of type I collagen, a blood marker of bone resorption, also occurred after 30 training sessions. The Inertial Exercise Trainer's large volume of training session repetitions elicited high peak force, peak acceleration and impulses that likely provided a mechanical loading stimulus that evoked calcaneal accretion.


Subject(s)
Muscle Strength/physiology , Osteogenesis/physiology , Resistance Training/methods , Absorptiometry, Photon , Adolescent , Adult , Biomarkers/blood , Bone Density , Bone Resorption , Diet , Female , Hip/physiology , Humans , Knee/physiology , Leg/physiology , Male , Young Adult
11.
Acad Med ; 92(7): 1022-1027, 2017 07.
Article in English | MEDLINE | ID: mdl-28657557

ABSTRACT

PURPOSE: To examine whether an intervention on proper use of electronic medical records (EMRs) in patient care could help improve medical students' empathic engagement, and to test the hypothesis that the training would reduce communication hurdles in clinical encounters. METHOD: Seventy third-year medical students from the Sidney Kimmel Medical College at Thomas Jefferson University were randomly divided into intervention and control groups during their six-week pediatric clerkship in 2012-2013. The intervention group received a one-hour training session on EMR-specific communication skills, including discussion of EMR use, the SALTED mnemonic and technique (Set-up, Ask, Listen, Type, Exceptions, Documentation), and role-plays. Both groups completed the Jefferson Scale of Empathy (JSE) at the clerkship's start and end. At clerkship's end, faculty and standardized patients (SPs) rated students' empathic engagement in SP encounters, using the Jefferson Scale of Patient Perceptions of Physician Empathy (JSPPPE), and their history-taking and communication skills. RESULTS: Faculty mean ratings on the JSPPPE, history-taking skills, and communication skills were significantly higher for the intervention group than the control group. SP mean ratings on history-taking skills were significantly higher for the intervention group than the control group. Both groups' JSE mean scores increased pretest to posttest, but the changes were not significant. The intervention group's posttest JSE mean score was higher than the control group's, but the difference was not significant. CONCLUSIONS: The findings suggest that a simple intervention providing specialized training in EMR-specific communication can improve medical students' empathic engagement in patient care, history-taking skills, and communication skills.


Subject(s)
Education, Medical/methods , Electronic Health Records , Empathy , Patient Care/psychology , Students, Medical/psychology , Communication , Female , Humans , Male , Medical History Taking/methods , Patient Care/methods , Pediatrics/education , Pediatrics/methods , Physician-Patient Relations
12.
Nurse Educ ; 42(1): 28-32, 2017.
Article in English | MEDLINE | ID: mdl-27391244

ABSTRACT

Stress, in the form of test anxiety, inhibits examination performance essential to nursing success. Salivary cortisol, a biomarker of stress, was obtained before 3 examinations and 1 nursing didactic class from a sample of baccalaureate nursing students in a midwestern US university. Significant differences were found between cortisol sampling events and by junior or senior status. These findings suggest that diverse examinations and program level yield differences in stress for students.


Subject(s)
Education, Nursing, Baccalaureate , Hydrocortisone/analysis , Saliva/chemistry , Students, Nursing/psychology , Test Anxiety Scale , Adult , Biomarkers/analysis , Educational Measurement , Female , Humans , Male , United States
13.
Dis Aquat Organ ; 109(3): 257-61, 2014 Jul 03.
Article in English | MEDLINE | ID: mdl-24991852

ABSTRACT

The octocoral disease aspergillosis is caused by the terrestrial fungus Aspergillus sydowii. The possibility of secondary (horizontal) transmission of aspergillosis among common sea fans Gorgonia ventalina would require waterborne transmission of hyphae and/or spores. A laboratory filtration experiment confirmed that fungal hyphae and spores were shed into the water by infected fans. This suggests that secondary infection might be possible in this species. It remains to be determined whether healthy fans actually develop aspergillosis after contact with hyphae-laden water.


Subject(s)
Anthozoa/microbiology , Aspergillus/physiology , Hyphae/isolation & purification , Spores, Fungal/isolation & purification , Animals , Caribbean Region , Ecosystem , Environmental Monitoring , Host-Pathogen Interactions , Hyphae/physiology , Spores, Fungal/physiology
14.
Nutrients ; 4(7): 585-601, 2012 07.
Article in English | MEDLINE | ID: mdl-22852051

ABSTRACT

ß-alanine is an amino acid that, when combined with histidine, forms the dipeptide carnosine within skeletal muscle. Carnosine and ß-alanine each have multiple purposes within the human body; this review focuses on their roles as ergogenic aids to exercise performance and suggests how to best quantify the former's merits as a buffer. Carnosine normally makes a small contribution to a cell's total buffer capacity; yet ß-alanine supplementation raises intracellular carnosine concentrations that in turn improve a muscle's ability to buffer protons. Numerous studies assessed the impact of oral ß-alanine intake on muscle carnosine levels and exercise performance. ß-alanine may best act as an ergogenic aid when metabolic acidosis is the primary factor for compromised exercise performance. Blood lactate kinetics, whereby the concentration of the metabolite is measured as it enters and leaves the vasculature over time, affords the best opportunity to assess the merits of ß-alanine supplementation's ergogenic effect. Optimal ß-alanine dosages have not been determined for persons of different ages, genders and nutritional/health conditions. Doses as high as 6.4 g day(-1), for ten weeks have been administered to healthy subjects. Paraesthesia is to date the only side effect from oral ß-alanine ingestion. The severity and duration of paraesthesia episodes are dose-dependent. It may be unwise for persons with a history of paraesthesia to ingest ß-alanine. As for any supplement, caution should be exercised with ß-alanine supplementation.


Subject(s)
Carnosine/metabolism , Dietary Supplements , beta-Alanine/administration & dosage , Acidosis, Lactic/metabolism , Exercise/physiology , Fatigue , Humans , Lactic Acid/blood , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism
15.
J Strength Cond Res ; 26(3): 625-32, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22310520

ABSTRACT

Our study purpose examined salivary hormonal responses to high-speed resistive exercise. Healthy subjects (n = 45) performed 2 elbow flexor workouts on a novel (inertial kinetic exercise; Oconomowoc, WI, USA) strength training device. Our methods included saliva sample collection at both preexercise and immediately postexercise; workouts entailed two 60-second sets separated by a 90-second rest period. The samples were analyzed in duplicate for their testosterone and cortisol concentrations ([T], [C]). Average and maximum elbow flexor torque were measured from each exercise bout; they were later analyzed with a 2(gender) × 2(workout) analysis of variance (ANOVA) with repeated measures for workout. The [T] and [C] each underwent a 2(gender) × 2(time) ANOVA with repeated measures for time. A within-subject design was used to limit error variance. Average and maximum torque each had gender (men > women; p < 0.05) effects. The [T] elicited a 2-way interaction (p < 0.05), as men incurred a significant 14% increase over time, but women's values were unchanged. Yet multivariate regression revealed that 3 predictor variables (body mass and average and maximum torques) did not account for a significant amount of variance associated with the rise in male [T]. Changes in [C] were not significant. In conclusion, changes in [T] concur with the results from other studies that showed significant elevations in male [T], despite the brevity of current workouts and the rather modest volume of muscle mass engaged. Practical applications imply that salivary assays may be a viable alternative to blood draws from athletes, yet coaches and others who may administer this treatment should know that our results may have produced greater pre-post hormonal changes if postexercise sample collection had occurred at a later time point.


Subject(s)
Hydrocortisone/physiology , Physical Exertion/physiology , Resistance Training , Saliva/chemistry , Testosterone/physiology , Female , Humans , Hydrocortisone/analysis , Male , Sex Factors , Testosterone/analysis
16.
Aviat Space Environ Med ; 83(2): 111-7, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22303589

ABSTRACT

INTRODUCTION: Elevated metabolism is common to spaceflight while exercise in microgravity exacerbates energy costs. Thus in-flight exercise countermeasures must be devised that minimize energy costs as they are performed on hardware operable in microgravity. METHODS: Female subjects (N = 28), subdivided into athletic and sedentary groups, each performed two workouts on a resistive exercise device (Impulse Training Systems; Newnan, GA). Comprised exclusively of either tonic or phasic repetitions, each exercise bout entailed two 1 -min sets interspersed by a 90-s rest from which the work volume was determined. Oxygen consumption was measured before, during, and after workouts until gas uptake returned to pre-exercise levels. Net oxygen consumption was converted to net energy expenditures via indirect calorimetry. Mean net energy expenditure and work volume values were each compared with 2 (athletes, sedentaries) x 2 (tonic, phasic) ANOVAs, with repeated measures for workout. In addition, multivariate regression employed three predictor (body mass, body fat percentage, work volume) variables to account for the net energy expenditure variance. RESULTS: Workouts yielded a metabolic cost of approximately 14 kcal, yet the data produced no significant intergroup or workout differences. However, work volume analysis yielded a significant (tonic > phasic) effect. The multivariate analysis explained small yet significant amounts of net energy expenditure variance. DISCUSSION: Current results: 1) are partly attributable to higher series elastic element activity seen with Impulse repetitions; and 2) offer new information with respect to in-flight exercise protocols for female astronauts.


Subject(s)
Energy Metabolism/physiology , Resistance Training , Analysis of Variance , Athletes , Calorimetry, Indirect , Female , Humans , Multivariate Analysis , Oxygen Consumption/physiology , Sedentary Behavior , Young Adult
17.
J Strength Cond Res ; 26(1): 40-6, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22090003

ABSTRACT

The purpose of our study was to assess data reproducibility from 2 consecutive front squat workouts, spaced 1 week apart, performed by American college football players (n = 18) as they prepared for their competitive season. For each workout, our methods entailed the performance of 3-6 front squat repetitions per set at 55, 65, and 75% of subject's 1 repetition maximum (1RM) load. In addition, a fourth set was done at a heavier load, with a resistance equal to 80 and 83% of their 1RM values, for the first and second workouts, respectively. A triple-axis accelerometer was affixed to a barbell to quantify exercise performance. Per load, the accelerometer measures peak values for the following indices: force, velocity, and power. To assess data reproducibility, inter-workout comparisons were made for 12 performance indices with 4 statistical test-retest measures: intraclass correlation coefficients, coefficients of variation (CVs), and the SEM expressed in both absolute and relative terms. Current results show that the majority of performance indices exceeded intraclass correlation (0.75-0.80) and CV (10-15%) values previously deemed as acceptable levels of data reproducibility. The 2 indices with the greatest variability were power and velocity values obtained at 55% of the 1RM load; thus, it was concluded that higher movement rates at the lightest load were the most difficult aspect of front squat performance to repeat successfully over time. Our practical applications imply lighter loads, with inherently higher rates of barbell movement, yield lower data reproducibility values.


Subject(s)
Resistance Training , Athletes , Football/physiology , Humans , Movement/physiology , Muscle, Skeletal/physiology , Reproducibility of Results , Resistance Training/instrumentation , Resistance Training/methods
18.
J Strength Cond Res ; 26(1): 284-92, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22090004

ABSTRACT

The current study purpose examined the vertical height-anthropometry relationship with jump data obtained from an instrumented platform. Our methods required college-aged (n = 177) subjects to make 3 visits to our laboratory to measure the following anthropometric variables: height, body mass, upper arm length (UAL), lower arm length, upper leg length, and lower leg length. Per jump, maximum height was measured in 3 ways: from the subjects' takeoff, hang times, and as they landed on the platform. Standard multivariate regression assessed how well anthropometry predicted the criterion variance per gender (men, women, pooled) and jump height method (takeoff, hang time, landing) combination. Z-scores indicated that small amounts of the total data were outliers. The results showed that the majority of outliers were from jump heights calculated as women landed on the platform. With the genders pooled, anthropometry predicted a significant (p < 0.05) amount of variance from jump heights calculated from both takeoff and hang time. The anthropometry-vertical jump relationship was not significant from heights calculated as subjects landed on the platform, likely due to the female outliers. Yet anthropometric data of men did predict a significant amount of variance from heights calculated when they landed on the platform; univariate correlations of men's data revealed that UAL was the best predictor. It was concluded that the large sample of men's data led to greater data heterogeneity and a higher univariate correlation. Because of our sample size and data heterogeneity, practical applications suggest that coaches may find our results best predict performance for a variety of college-aged athletes and vertical jump enthusiasts.


Subject(s)
Anthropometry , Athletic Performance , Arm/anatomy & histology , Body Height , Body Mass Index , Female , Humans , Leg/anatomy & histology , Male , Movement
19.
J Strength Cond Res ; 26(9): 2460-7, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22027858

ABSTRACT

The purpose of our study was to examine the ability of anthropometric variables (body mass, total arm length, biacromial width) to predict bench press performance at both maximal and submaximal loads. Our methods required 36 men to visit our laboratory and submit to anthropometric measurements, followed by lifting as much weight as possible in good form one time (1 repetition maximum, 1RM) in the exercise. They made 3 more visits in which they performed 4 sets of bench presses to volitional failure at 1 of 3 (40, 55, or 75% 1RM) submaximal loads. An accelerometer (Myotest Inc., Royal Oak MI) measured peak force, velocity, and power after each submaximal load set. With stepwise multivariate regression, our 3 anthropometric variables attempted to explain significant amounts of variance for 13 bench press performance indices. For criterion measures that reached significance, separate Pearson product moment correlation coefficients further assessed if the strength of association each anthropometric variable had with the criterion was also significant. Our analyses showed that anthropometry explained significant amounts (p < 0.05) of variance for 8 criterion measures. It was concluded that body mass had strong univariate correlations with 1RM and force-related measures, total arm length was moderately associated with 1RM and criterion variables at the lightest load, whereas biacromial width had an inverse relationship with the peak number of repetitions performed per set at the 2 lighter loads. Practical applications suggest results may help coaches and practitioners identify anthropometric features that may best predict various measures of bench press prowess in athletes.


Subject(s)
Anthropometry , Muscle Strength , Weight Lifting , Accelerometry , Adult , Arm/anatomy & histology , Body Height , Body Weight , Humans , Male , Young Adult
20.
Aviat Space Environ Med ; 81(9): 825-32, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20824988

ABSTRACT

INTRODUCTION: Numerous variables impact resultant testosterone concentrations (TC) that foretell the efficacy of workouts. Identifying variables may aid the development of in-flight exercise prescription. METHODS: To identify variables that predict the variance in TC from flywheel ergometer exercise, 17 subjects did 3 workouts in a randomized order. Comprised of 10-repetition leg press sets, workouts entailed either: 1) 3 sets of both concentric and eccentric muscle actions (CE3), and concentric-only actions done for 2) three (CO3), or 3) six (CO6) sets. Venous plasma TC were collected before and at 1 and 30 min postexercise. The last two collection points served as criterion measures. Body mass, delta blood lactate levels, peak angular velocity, average power, and total work from workouts were used to predict the variance in TC. RESULTS: Predictor variables accounted for significant levels of variance at both 1 and 30 min post-exercise for both the CE3 and the concentric-only (CO3 and CO6 bouts combined) workouts using multivariate regression. Inclusion of eccentric variables (only collected from the CE3 bout; r2 = 0.90) predicted nearly twice the variance than the concentric-only (r2 = 0.54) workouts. CONCLUSIONS: Body mass and average power indices were the best predictors of the variance in post-workout TC. Since a flywheel-based device is used to abate in-flight muscle atrophy and strength losses, exercise prescriptions may wish to monitor these indices as they impacted post-workout TC to the greatest extent. Future research should assess why eccentric variables increased the amount of explained variance from flywheel ergometer workouts.


Subject(s)
Exercise Test/instrumentation , Exercise/physiology , Resistance Training , Testosterone/blood , Biomarkers/blood , Body Mass Index , Female , Humans , Male , Young Adult
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