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1.
J Strength Cond Res ; 37(12): 2467-2476, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38015736

RESUMO

ABSTRACT: Boffey, D, DiPrima, JA, Kendall, KL, Hill, EC, Stout, JR, and Fukuda, DH. Influence of body composition, load-velocity profiles, and sex-related differences on army combat fitness test performance. J Strength Cond Res 37(12): 2467-2476, 2023-The Army Combat Fitness Test (ACFT) became the U.S. Army's mandatory physical fitness test in April of 2022. The purpose of this study was to determine the relationship between ACFT performance and both body composition and velocity profiles and to determine sex differences for these variables. Data were collected at 2 timepoints 4 months apart, from male (n = 55) and female (n = 17) Army Reserve Officers' Training Corps (ROTC) cadets. Body composition was assessed with a bioelectrical impedance spectroscopy device, and cadets completed a hex bar deadlift load-velocity profile (LVP) and ACFT on separate days. Stepwise multiple regressions were used to explain the amount of variance in ACFT total score and individual event performance. Significance for statistical tests was defined as an alpha level of p ≤ 0.05. Muscle mass and body fat percentage accounted for 49% of shared variance of total ACFT score, and deadlift maximal power and maximal velocity accounted for 67% of shared variance of total ACFT score. The 3 repetition maximum deadlift, standing power throw, hand-release push-up, and sprint-drag-carry events favored cadets with more muscle mass, whereas the leg tuck was influenced by the body fat percentage and the 2-mile run was affected by fat mass. Sex had greater predictive capability for the 2-mile run than body composition. Men outperformed women on all individual events, with the greatest differences on standing power throw and sprint-drag-carry. It is recommended that Army ROTC cadets taking the ACFT maximize lower-body power production and increase muscle mass.


Assuntos
Teste de Esforço , Militares , Humanos , Masculino , Feminino , Teste de Esforço/métodos , Caracteres Sexuais , Aptidão Física/fisiologia , Exercício Físico , Composição Corporal
2.
J Strength Cond Res ; 37(10): 1929-1938, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37729510

RESUMO

ABSTRACT: Nagatani, T, Kendall, KL, Guppy, SN, Poon, WCK, and Haff, GG. Effect of 3 different set configurations on kinematic variables and internal loads during a power snatch session. J Strength Cond Res 37(10): 1929-1938, 2023-The aim of this study was to investigate the effect of 3 different set configurations on kinematic variables and internal loads during multiple sets performed with the power snatch. Ten strength-power athletes with at least 6 months of training experience performing the power snatch participated in this study, which consisted of 3 experimental protocols performed in a randomized repeated-measures design. The 3 protocols involved performing the power snatch for 3 sets of 5 repetitions at an average load of 75% 1 repetition maximum with a traditional (TRAD), cluster (CLU), or ascending cluster (A-CLU) protocol, where the training load was progressively increased across the set. Kinematic variables and internal loads (heart rate, blood lactate, and rate of perceived exertion) were measured during each protocol. The athletes maintained peak velocity (PV) and peak power (PP) and exhibited lower internal loads during CLU sets when compared with TRAD sets, whereas they displayed significant decreases in PV during TRAD sets. However, there were no statistically significant differences in PV and PP responses between the TRAD and CLU protocol. The athletes exhibited a significant decrease in PV, whereas PP was increased across each set in the A-CLU protocol, with lower internal loads observed compared with the TRAD protocol. Overall, the training loads used in this study do not appear to maximize the benefits of using CLU set during 3 sets of power snatches performed for 5 repetitions. In addition, A-CLU sets may potentially be useful as a means of maximizing the power output of the athlete.


Assuntos
Atletas , Humanos , Fenômenos Biomecânicos , Frequência Cardíaca
3.
Int J Exerc Sci ; 15(1): 632-644, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35989700

RESUMO

Force plates are commonly used when assessing vertical jumping performance but are not always affordable or practical tools for all testing situations. Twenty-four participants volunteered to take part in a study investigating the agreement between bilateral force plates and a new commercially available contact mat that records jump height, flight-time (FT), and FT of individual limbs during both countermovement (CMJ) and squat (SJ) jumps. Each participant performed six jumps of each type while standing on a contact mat placed upon a pair of in-ground force plates. When compared to the force plate via ordinary least products regression, the contact mat agreed with force plate CMJ and SJ jump height, individual limb FT during CMJs, and left-leg FT during SJs. The bilateral contact mat provided valid assessment of individual limb FT during CMJs, but not SJs. Practitioners can therefore use a bilateral contact mat interchangeably with bilateral force plates to measure SJ and CMJ performance.

4.
J Strength Cond Res ; 35(6): 1535-1541, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34027920

RESUMO

ABSTRACT: Herda, AA, Smith-Ryan, AE, Kendall, KL, Cramer, JT, and Stout, JR. Evaluation of high-intensity interval training and beta-alanine supplementation on efficiency of electrical activity and electromyographic fatigue threshold. J Strength Cond Res 35(6): 1535-1541, 2021-The purpose of this study was to determine the effects of high-intensity interval training (HIIT) with or without ß-alanine (BA) supplementation on the electromyographic fatigue threshold (EMGFT) and efficiency of electrical activity (EEA) in young women. Forty-four women (mean ± SD; age [yrs]: 21.7 ± 3.7; height [cm]: 166.3 ± 6.4; body mass [kg]: 66.1 ± 10.3) were randomly assigned to one of 3 treatment groups. The supplement groups performed HIIT on the cycle ergometer 3 times·wk-1 for 6 weeks. Electromyographic fatigue threshold and EEA were assessed at baseline (PRE), after 3 weeks of training (MID), and after 6 weeks of HIIT (POST). Two 2-way mixed factorial analyses of variance (time [PRE vs. MID vs. POST] × treatment (BA vs. PL vs. CON)] were used to analyze EMGFT and EEA with a predetermined level of significance α of 0.05. For EMGFT, there was no interaction (p = 0.26) and no main effect for time (p = 0.28) nor treatment (p = 0.86); thus, there were no changes in EMGFT regardless of training or supplementation status. For EEA, there was no interaction (p = 0.70) nor treatment (p = 0.79); however, there was a main effect for time (p < 0.01). Our findings indicated that neither training nor supplementation was effective in improving EMGFT in women. Efficiency of electrical activity was altered, potentially because of a learning effect. Coaches and practitioners may not use these tests to monitor training status; however, they may find EEA as a useful tool to track cycling efficiency.


Assuntos
Treinamento Intervalado de Alta Intensidade , Suplementos Nutricionais , Eletromiografia , Teste de Esforço , Fadiga , Feminino , Humanos , Fadiga Muscular , Consumo de Oxigênio , beta-Alanina
6.
J Diet Suppl ; 14(6): 653-666, 2017 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-28388294

RESUMO

The increasing interest in weight loss has seen a concurrent rise in the supplemental use of thermogenics to aid weight loss efforts. To date, the effectiveness and safety of supplemental proprietary blend thermogenics, in conjunction with high-protein energy-restricted diets have not been thoroughly evaluated. The purpose of this study was to investigate the efficacy of a low-calorie, high-protein diet with and without the concomitant use of a thermogenic supplement on body weight and body composition in apparently healthy females. Subjects were divided into three groups, Bizzy Diet+FitMiss Burn (BURN, N = 12), Bizzy Diet+Placebo (PLA, N = 13), and Control (CON, N = 14), and underwent two testing sessions separated by approximately 3 weeks. Resting blood pressure (BP), resting heart rate (RHR), clinical safety markers, body weight (BW), and body composition were assessed during each testing session. Repeated measures analysis of variance (ANOVA) revealed a significant effect for time relative to BW, total body fat mass (FM), leg FM, and trunk FM. Post hoc analysis revealed that the BURN and PLA groups experienced significant decreases in both BW and total body FM compared to CON (p <.05). There were no significant interactions for BP, RHR, or clinical safety markers over the course of the study. The Bizzy Diet, both with and without the addition of FitMiss Burn thermogenic, appears to be safe for short-term use and may lead to greater improvement in body composition and BW in an apparently healthy female population.


Assuntos
Restrição Calórica , Dieta Redutora , Suplementos Nutricionais , Micronutrientes/administração & dosagem , Adolescente , Adulto , Pressão Sanguínea/efeitos dos fármacos , Composição Corporal , Índice de Massa Corporal , Dieta Rica em Proteínas , Método Duplo-Cego , Exercício Físico , Feminino , Humanos , Termogênese , Adulto Jovem
7.
Clin Physiol Funct Imaging ; 37(4): 456-458, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26667901

RESUMO

This investigation aimed to compare hydrostatic weighing (HW) with near-infrared interactance (NIR) and skinfold measurements (SKF) in estimating body fat percentage (FAT%) in rowing athletes. FAT% was estimated in 20 elite male rowers (mean ± SD: age = 24·8 ± 2·2 years, height = 191·0 ± 6·8 cm, weight = 86·8 ± 11·3 kg, HW FAT% = 11·50 ± 3·16%) using HW with residual volume, 3-site SKF and NIR on the biceps brachii. Predicted FAT% values for NIR and SKF were validated against the criterion method of HW. Constant error was not significant for NIR (-0·06, P = 0·955) or SKF (-0·20, P = 0·813). Neither NIR (r = 0·045) nor SKF (r = 0·229) demonstrated significant validity coefficients when compared to HW. The standard error of the estimate values for NIR and SKF were both less than 3·5%, while total error was 4·34% and 3·60%, respectively. When compared to HW, SKF and NIR provide similar mean values when compared to HW, but the lack of apparent relationships between individual values and borderline unacceptable total error may limit their application in this population.


Assuntos
Adiposidade , Atletas , Aptidão Física , Espectroscopia de Luz Próxima ao Infravermelho/instrumentação , Esportes Aquáticos , Adulto , Desenho de Equipamento , Humanos , Masculino , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Dobras Cutâneas , Adulto Jovem
8.
J Strength Cond Res ; 31(2): 395-402, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27359205

RESUMO

Hemmings, TJ, Kendall, KL, and Dobson, JL. Identifying dosage effect of light-emitting diode therapy on muscular fatigue in quadriceps. J Strength Cond Res 31(2): 395-402, 2017-The purpose of this study was to compare the effects of various dosages of light-emitting diode therapy (LEDT) on muscle fatigue while performing a single-leg extension to exhaustion. A total of 34 recreationally resistance-trained athletes between the ages of 18 and 26 participated in 4 trials. Each trial included pre-exercise/postexercise blood lactate measurements and 2 sets of 3 maximal voluntary isometric contractions (MVICs), followed by LEDT on 6 points across the superficial quadriceps. Each randomized trial consisted of a placebo, 30, 60, or 120 seconds on each point on the quadriceps. Three minutes after LEDT, the participants performed an eccentric leg extension with 120% of MVIC until fatigue. There was significant increase in the number of repetitions performed between the placebo treatment and 60 seconds (p = 0.023), as well as placebo and 120 seconds (p = 0.004) of irradiation on each point. There were no significant differences in blood lactate levels between any of the 4 trials. In conclusion, LEDT had a positive effect on performance when irradiating 6 points on the superficial quadriceps for 60 and 120 seconds before an eccentric leg extension.


Assuntos
Exercício Físico/fisiologia , Terapia com Luz de Baixa Intensidade/métodos , Fadiga Muscular/fisiologia , Músculo Quadríceps/fisiologia , Adolescente , Adulto , Atletas , Método Duplo-Cego , Feminino , Humanos , Contração Isométrica , Ácido Láctico/sangue , Masculino , Adulto Jovem
9.
J Sports Sci ; 35(7): 624-633, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27159216

RESUMO

The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.


Assuntos
Composição Corporal , Compartimentos de Líquidos Corporais/metabolismo , Pesos e Medidas Corporais/métodos , Modelos Biológicos , Esportes , Absorciometria de Fóton , Tecido Adiposo/metabolismo , Adulto , Atletas , Água Corporal , Densidade Óssea , Impedância Elétrica , Humanos , Masculino , Pletismografia , Reprodutibilidade dos Testes , Dobras Cutâneas , Ultrassonografia , Água , Adulto Jovem
10.
J Am Coll Nutr ; 36(1): 16-27, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27710436

RESUMO

OBJECTIVE: The objective of this study was to compare the chronic effects of different whey protein forms on body composition and performance when supplemented with resistance training. METHODS: Resistance-trained men (N = 56, 21.4 ± 0.4 years, 79.5 ± 1.0 kg) participated in an 8-week resistance training regimen (2 upper-body sessions and 2 lower-body sessions per week) and received one of 4 double-blinded treatments: 30 g/serving carbohydrate placebo (PLA) or 30 g/serving protein from either (a) 80% whey protein concentrate (WPC), (b) high-lactoferrin-containing WPC (WPC-L), or (c) extensively hydrolyzed WPC (WPH). All subjects consumed 2 servings of treatment per day; specifically, once immediately before and after training and between meals on nontraining days. Blood collection, one repetition maximum (1RM) testing for bench press and hack squat, and body composition assessment using dual-energy x-ray absorptiometry (DXA) occurred prior to training and 48 hours following the last training session. RESULTS: Total body skeletal muscle mass increased in all groups (p < 0.0125). There were similar between-group increases in upper-body (4%-7%, analysis of covariance [ANCOVA] interaction p = 0.73) and lower-body (24%-35%, ANCOVA interaction p = 0.85) 1RM strength following the intervention. Remarkably, WPH reduced fat mass (-6%), which was significantly different from PLA (+4.4%, p < 0.0125). No time or between-group differences were present for serum markers of health, metabolism, or muscle damage, with the exception of blood urea nitrogen being significantly lower for WPH than WPC (p < 0.05) following the intervention. CONCLUSIONS: WPH may augment fat loss but did not provide any other advantages when used in combination with resistance training. More mechanistic research is needed to examine how WPH affects adipose tissue physiology.


Assuntos
Exercício Físico/fisiologia , Treinamento Resistido , Proteínas do Soro do Leite/administração & dosagem , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/fisiologia , Adulto , Composição Corporal/efeitos dos fármacos , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Lactoferrina/administração & dosagem , Masculino , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/fisiologia , Hidrolisados de Proteína/administração & dosagem , Adulto Jovem
11.
J Strength Cond Res ; 30(12): 3525-3530, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27861264

RESUMO

Hyde, PN, Kendall, KL, Fairman, CM, Coker, NA, Yarbrough, ME, and Rossi, SJ. Utilization of B-mode ultrasound as a body fat estimate in collegiate football players. J Strength Cond Res 30(12): 3525-3530, 2016-The purpose of the present study was to validate a 7-site ultrasound imaging protocol to predict the percent body fat (%BF) in a division I football team. Body composition was estimated by ultrasound, 7-site skinfolds, and the 3-compartment-water (3C-W) model of Siri, using bioimpedance spectroscopy to estimate the total body water and air displacement plethysmography (using BODPOD) to determine the body density. Pearson's product-moment correlation analyses were run to determine correlations between ΣUltrasound and the criterion 3C-W, and between the ΣSkinfold and ΣUltrasound. Strong positive correlations were observed between ΣSkinfold and ΣUltrasound (r = 0.984; p < 0.001). Furthermore, a strong positive correlation was observed between ΣUltrasound and %BF from 3C-W (r = 0.878; p < 0.001). Based on the significant correlation analysis, a linear regression equation was developed to predict the %BF from ΣUltrasound, using %BF from the 3C-W model as the dependent variable: %BF = 6.194 + (0.096 × ΣUltrasound); standard error of the estimate (SEE) = 2.97%. Cross-validation analyses were performed using an independent sample of 29 players. The mean observed %BF from the 3C-W model and the mean predicted %BF were 18.32 ± 6.26% and 18.78 ± 6.22%, respectively. The constant error, SEE, and validity coefficient (r) were 0.87%, 2.64%, and 0.91%, respectively. The total error was 2.87%. The positive relationship between ultrasound measurements and the 3C-W model suggests that ultrasound imaging may be a practical alternative to predicting %BF in division I football players.


Assuntos
Atletas , Composição Corporal , Dobras Cutâneas , Gordura Subcutânea/diagnóstico por imagem , Água Corporal , Estudos Transversais , Futebol Americano , Humanos , Masculino , Pletismografia de Impedância , Reprodutibilidade dos Testes , Ultrassonografia , Adulto Jovem
12.
Int J Exerc Sci ; 9(1): 101-109, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27293508

RESUMO

Breast Cancer survivors can experience a myriad of physical and psychological benefits as a result of regular exercise. This study aimed to build on previous research using lower impact exercise programs by using an antigravity (Alter-G®) treadmill to administer cardiovascular training. The purpose of this study was to determine the effectiveness a physical activity program, including an Alter-G® treadmill, for improving physiological and psychosocial measures in female breast cancer survivors. A 14-week intervention using an AB-AB study design was employed. Six female breast cancer survivors were recruited to participate in the study. Participants attended three 60-minute sessions per week, consisting of a combination of muscular strength/endurance, and cardiovascular endurance exercises. Consistent with current literature and guidelines, exercise interventions were individualized and tailored to suit individuals. Data was collected and analyzed in 2013. Visual inspection of results found improvements in cardiovascular endurance and measures of body composition. Quality of life was maintained and in some cases, improved. Finally, no adverse effects were reported from the participants, and adherence to the program for those who completed the study was 97%. The results of this study suggest that the use of a physical activity program in combination with an Alter-G® treadmill may provide practical and meaningful improvements in measures of cardiovascular endurance and body composition.

13.
Exp Gerontol ; 74: 9-12, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26657810

RESUMO

Raw bioelectrical impedance analysis (BIA) data [resistance (R); reactance (Xc)] through bioelectrical impedance vector analysis (BIVA) and phase angle (PhA) have been used to evaluate cellular function and hydration status. The purpose of this investigation was to examine the effects of resistance training (RT) on classic and specific BIVA in elderly women. Twenty women (mean ± SD; age: 71.9 ± 6.9 years; BMI: 24.5 ± 3.0 kg m(-2)) completed a 6-month RT program. Whole-body, single-frequency BIA, body geometry, and leg strength (5RM) measures were completed at baseline (t0), 3 months (t3), and 6 months (t6). The mean impedance vector displacements were compared using Hotelling's T(2) test to evaluate changes in R and Xc relative to height (R/ht; Xc/ht) or body volume (Rsp; Xcsp) estimated from the arms, legs, and trunk. 5RM, PhA, and BIVA variables were compared using ANOVA. PhA improved at t6 (p < 0.01), while 5RM improved at t3 and t6 (p < 0.01). Using classic BIVA, 6 months (T(2) = 31.6; p < 0.01), but not 3 months of RT (T(2) = 4.5; p = 0.20), resulted in significant vector migration. Using specific BIVA, 6 months (T(2) = 24.4; p < 0.01), but not 3 months of RT (T(2) = 5.5; p = 0.10), also resulted in significant vector migration. 5RM was correlated to both PhA (r = 0.48-56) and Xcsp (r = 0.45-53) at all time points. Vector displacements were likely the result of improved cellular integrity (Xcsp) and cellular health (PhA).


Assuntos
Composição Corporal , Treinamento Resistido , Adaptação Fisiológica , Fatores Etários , Idoso , Envelhecimento , Antropometria , Impedância Elétrica , Feminino , Avaliação Geriátrica , Humanos , Estudos Longitudinais , Força Muscular , Fatores de Tempo , Resultado do Tratamento , Equilíbrio Hidroeletrolítico
14.
Exp Gerontol ; 64: 33-4, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25700845

RESUMO

The effects of 12-weeks of HMB ingestion and resistance training (RT) on abdominal adiposity were examined in 48 men (66-78 yrs). All participants were randomly assigned to 1 of 4 groups: no-training placebo (NT-PL), HMB only (NT-HMB), RT with PL (RT-PL), or HMB with RT (RT-HMB). DXA was used to estimate abdominal fat mass (AFM) by placing the region of interest over the L1-L4 region of the spine. Outcomes were assessed by ANCOVA, with Bonferroni-corrected pairwise comparisons. Baseline AFM values were used as the covariate. The ANCOVA indicated a significant difference (p = 0.013) between group means for the adjusted posttest AFM values (mean (kg) ± SE: NT-PL = 2.59 ± 0.06; NT-HMB = 2.59 ± 0.61; RT-PL = 2.59 ± 0.62; RT-HMB = 2.34 ± 0.61). The pairwise comparisons indicated that AFM following the intervention period in the RT-HMB group was significantly less than NT-PL (p = 0.013), NT-HMB (p = 0.011), and RT-PL (p = 0.010). These data suggested that HMB in combination with 12 weeks of RT decreased AFM in elderly men.


Assuntos
Gordura Abdominal , Adiposidade/efeitos dos fármacos , Treinamento Resistido , Valeratos/farmacologia , Idoso , Suplementos Nutricionais , Método Duplo-Cego , Humanos , Masculino
15.
Nutr Res ; 34(5): 442-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24916558

RESUMO

The purpose of this study was to determine the safety and efficacy of consuming a preworkout supplement (SUP) containing caffeine, creatine, ß-alanine, amino acids, and B vitamins for 28 days. We hypothesized that little to no changes in kidney and liver clinical blood markers or resting heart rate and blood pressure (BP) would be observed. In addition, we hypothesized that body composition and performance would improve in recreationally active males after 28 days of supplementation. In a double-blind, placebo-controlled study, participants were randomly assigned to ingest one scoop of either the SUP or placebo every day for 28 days, either 20 minutes before exercise or ad libitum on nonexercise days. Resting heart rate and BP, body composition, and fasting blood samples were collected before and after supplementation. Aerobic capacity as well as muscular strength and endurance were also measured. Significant (P < .05) main effects for time were observed for resting heart rate (presupplementation, 67.59 ± 7.90 beats per minute; postsupplementation, 66.18 ± 7.63 beats per minute), systolic BP (presupplementation, 122.41 ± 11.25 mm Hg; postsupplementation, 118.35 ± 11.58 mm Hg), blood urea nitrogen (presupplementation, 13.12 ± 2.55 mg/dL; postsupplementation, 15.24 ± 4.47 mg/dL), aspartate aminotransferase (presupplementation, 34.29 ± 16.48 IU/L; postsupplementation, 24.76 ± 4.71 IU/L), and alanine aminotransferase (presupplementation, 32.76 ± 19.72 IU/L; postsupplementation, 24.88 ± 9.68 IU/L). Significant main effects for time were observed for body fat percentage (presupplementation, 15.55% ± 5.79%; postsupplementation, 14.21% ± 5.38%; P = .004) and fat-free mass (presupplementation, 70.80 ± 9.21 kg; postsupplementation, 71.98 ± 9.27 kg; P = .006). A significant decrease in maximal oxygen consumption (presupplementation, 47.28 ± 2.69 mL/kg per minute; postsupplementation, 45.60 ± 2.81 mL/kg per minute) and a significant increase in percentage of oxygen consumption per unit time at which ventilatory threshold occurred (presupplementation, 64.38% ± 6.63%; postsupplementation, 70.63% ± 6.39%) and leg press one-repetition maximum (presupplementation, 218.75 ± 38.43 kg; postsupplementation, 228.75 ± 44.79 kg) were observed in the SUP only. No adverse effects were noted for renal and hepatic clinical blood markers, resting heart rate, or BP. Supplements containing similar ingredients and doses should be safe for ingestion periods lasting up to 28 days in healthy, recreationally trained, college-aged men.


Assuntos
Aminoácidos/farmacologia , Cafeína/farmacologia , Suplementos Nutricionais , Exercício Físico/fisiologia , Força Muscular/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Complexo Vitamínico B/farmacologia , Adolescente , Pressão Sanguínea/efeitos dos fármacos , Nitrogênio da Ureia Sanguínea , Composição Corporal/efeitos dos fármacos , Creatina/farmacologia , Suplementos Nutricionais/efeitos adversos , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Consumo de Oxigênio/efeitos dos fármacos , Resistência Física/fisiologia , Recreação , Transaminases/sangue , Resultado do Tratamento , Adulto Jovem , beta-Alanina/farmacologia
16.
Int J Sports Physiol Perform ; 9(6): 966-72, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24622942

RESUMO

PURPOSE: To assess changes in body composition, lumbar-spine bone mineral density (BMD), and rowing performance in college-level rowers over a competition season. METHODS: Eleven Division I college rowers (mean ± SD 21.4 ± 3.7 y) completed 6 testing sessions throughout the course of their competition season. Testing included measurements of fat mass, bone-free lean mass (BFLM), body fat (%BF), lumbar-spine BMD, and 2000-m time-trial performance. After preseason testing, rowers participated in a periodized training program, with the addition of resistance training to the traditional aerobic-training program. RESULTS: Significant (P < .05) improvements in %BF, total mass, and BFLM were observed at midseason and postseason compared with preseason. Neither lumbar-spine BMD nor BMC significantly changed over the competitive season (P > .05). Finally, rowing performance (as measured by 2000-m time and average watts achieved) significantly improved at midseason and postseason compared with preseason. CONCLUSION: Our results highlight the efficacy of a seasonal concurrent training program serving to improve body composition and rowing performance, as measured by 2000-m times and average watts, among college-level rowers. Our findings offer practical applications for coaches and athletes looking to design a concurrent strength and aerobic training program to improve rowing performance across a season.


Assuntos
Composição Corporal , Densidade Óssea , Educação Física e Treinamento/métodos , Esportes/fisiologia , Adolescente , Feminino , Humanos , Vértebras Lombares , Masculino , Força Muscular/fisiologia , Resistência Física/fisiologia , Treinamento Resistido , Adulto Jovem
17.
Appl Physiol Nutr Metab ; 39(1): 38-46, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24383505

RESUMO

ß-Alanine (BA) has been linked with oxidative protection. This study evaluated antioxidant properties of BA. Twenty-five men consumed BA or placebo for 4 weeks, and completed a 40-min run to induce oxidative stress. Blood draws were taken to measure 8-isoprostane, total antioxidant capacity, superoxide dismutase, and glutathione. BA had no significant influence on reducing exercise-induced oxidative stress. Confidence intervals suggest a reduction in lipid peroxidation. BA supplementation may have little influence as an antioxidant.


Assuntos
Antioxidantes/farmacologia , Suplementos Nutricionais , Exercício Físico/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , beta-Alanina/farmacologia , Biomarcadores/sangue , Humanos , Masculino , Adulto Jovem
18.
Exp Gerontol ; 48(12): 1479-88, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24140621

RESUMO

The purpose of this investigation was to determine body composition classification using field-based testing measurements in healthy elderly men and women. The use of isoperformance curves is presented as a method for this determination. Baseline values from 107 healthy Caucasian men and women, over the age of 65years old, who participated in a separate longitudinal study, were used for this investigation. Field-based measurements of age, height, weight, body mass index (BMI), and handgrip strength were recorded on an individual basis. Relative skeletal muscle index (RSMI) and body fat percentage (FAT%) were determined by dual-energy X-ray absorptiometry (DXA) for each participant. Sarcopenia cut-off values for RSMI of 7.26kg·m(-2) for men and 5.45kg·m(-2) for women and elderly obesity cut-off values for FAT% of 27% for men and 38% for women were used. Individuals above the RSMI cut-off and below the FAT% cut-off were classified in the normal phenotype category, while individuals below the RSMI cut-off and above the FAT% cut-off were classified in the sarcopenic-obese phenotype category. Prediction equations for RSMI and FAT% from sex, BMI, and handgrip strength values were developed using multiple regression analysis. The prediction equations were validated using double cross-validation. The final regression equation developed to predict FAT% from sex, BMI, and handgrip strength resulted in a strong relationship (adjusted R(2)=0.741) to DXA values with a low standard error of the estimate (SEE=3.994%). The final regression equation developed to predict RSMI from the field-based testing measures also resulted in a strong relationship (adjusted R(2)=0.841) to DXA values with a low standard error of the estimate (SEE=0.544kg·m(-2)). Isoperformance curves were developed from the relationship between BMI and handgrip strength for men and women with the aforementioned clinical phenotype classification criteria. These visual representations were used to aid in the classification and evaluation of sarcopenia, obesity, and sarcopenic-obesity in elderly individuals. Future research should replicate the current findings with an increased sample size and the development of tailored interventions for each body composition category.


Assuntos
Envelhecimento , Composição Corporal , Obesidade/diagnóstico , Sarcopenia/diagnóstico , Absorciometria de Fóton , Adiposidade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Estatura , Índice de Massa Corporal , Peso Corporal , Feminino , Força da Mão , Humanos , Modelos Lineares , Masculino , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/fisiopatologia , Obesidade/diagnóstico por imagem , Obesidade/fisiopatologia , Fenótipo , Valor Preditivo dos Testes , Valores de Referência , Reprodutibilidade dos Testes , Sarcopenia/diagnóstico por imagem , Sarcopenia/fisiopatologia , Fatores Sexuais
19.
Exp Gerontol ; 48(11): 1303-10, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23981904

RESUMO

BACKGROUND: Evidence suggests CaHMB may impact muscle mass and/or strength in older adults, yet no long-term studies have compared its effectiveness in sedentary and resistance training conditions. The purpose of this study was to evaluate the effects of 24 weeks of CaHMB supplementation and resistance training (3 d wk(-1)) or CaHMB supplementation only in ≥65 yr old adults. METHODS: This double-blinded, placebo-controlled, trial occurred in two phases under ad libitum conditions. Phase I consisted of two non-exercise groups: (a) placebo and (b) 3 g CaHMB consumed twice daily. Phase II consisted of two resistance exercise groups: (a) placebo and resistance exercise and (b) 3 g CaHMB consumed twice daily and resistance exercise (RE). Strength and functionality were assessed in both phases with isokinetic leg extension and flexion at 60°·s(-1) and 180°·s(-1) (LE60, LF60, LE180, LF180), hand grip strength (HG) and get-up-and-go (GUG). Dual X-Ray Absorptiometry (DXA) was used to measure arm, leg, and total body lean mass (LM) as well as total fat mass (FM). Muscle Quality was measured for arm (MQ(HG)=HG/arm LM) and Leg (MQ60=LE60/leg LM) (MQ180=LE180/leg LM). RESULTS: At 24 weeks of Phase I, change in LE60 (+8.8%) and MQ180 (+20.8%) for CaHMB was significantly (p<0.05) greater than that for placebo group. Additionally, only CaHMB showed significant (p<0.05) improvements in total LM (2.2%), leg LM (2.1%), and LE180 (+17.3%), though no treatment effect was observed. Phase II demonstrated that RE significantly improved total LM (4.3%), LE60 (22.8%), LE180 (21.4%), HG (9.8%), and GUG (10.2%) with no difference between treatment groups. At week 24, only CaHMB group significantly improved FM (-3.8%) and MQHG (7.3%); however there was no treatment main effect for these variables. CONCLUSION: CaHMB improved strength and MQ without RE. Further, RE is an effective intervention for improving all measures of body composition and functionality.


Assuntos
Envelhecimento/fisiologia , Treinamento Resistido , Valeratos/uso terapêutico , Idoso , Envelhecimento/patologia , Composição Corporal/efeitos dos fármacos , Composição Corporal/fisiologia , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Força da Mão/fisiologia , Humanos , Masculino , Força Muscular/efeitos dos fármacos , Força Muscular/fisiologia , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/patologia , Músculo Esquelético/fisiologia , Atrofia Muscular/patologia , Atrofia Muscular/fisiopatologia , Atrofia Muscular/terapia , Projetos Piloto , Valeratos/administração & dosagem
20.
J Strength Cond Res ; 27(2): 331-9, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22476167

RESUMO

The purpose of this study was to characterize the adaptations imposed by 4 weeks of precompetition judo training in youth athletes. It was hypothesized that anthropometric and sport-specific performance would improve during the preparation for a junior national championship event. Twenty youth athletes (mean ± SD; chronological age: 13.1 ± 3.2 years; training age: 5.3 ± 3.5 years; judo experience: 7.8 ± 2.5 hours per week) completed pretesting and posttesting procedures. Child (12 years old; n = 8) and adolescent (13 years old; n = 12) groups were evaluated to determine the anthropometric and sport-specific performance changes caused by 4 weeks of judo training conducted in preparation for the junior national championships. The child group showed an increase in flexibility (11.5%), and the adolescent group showed a decrease in skinfold thickness (-12.2%); increased jumping power (26.7%), force (7.7%), and velocity (19.0%); and improved judo-specific ability (-5.9%), as measured by the Special Judo Fitness Test (SJFT) index. Additionally, the SJFT index for all the study participants was shown to be inversely correlated to handgrip strength (r = -0.681), rope pull performance (r = -0.545), and jump height (r = -0.503). These results support the use of preparatory judo training in the improvement of anthropometric and sport-specific measures in adolescent athletes. Furthermore, the outcomes from this study provide direction for coaches and trainers in their efforts to impact physical performance and judo skills in children and adolescents through precompetition training.


Assuntos
Desempenho Atlético/fisiologia , Exercício Físico/fisiologia , Artes Marciais/fisiologia , Adolescente , Estatura , Peso Corporal , Criança , Feminino , Força da Mão/fisiologia , Humanos , Extremidade Inferior , Masculino , Destreza Motora/fisiologia , Movimento , Força Muscular , Músculo Esquelético/fisiologia , Amplitude de Movimento Articular , Dobras Cutâneas
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