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1.
Int J Sports Med ; 45(9): 690-697, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38729165

RESUMEN

This study investigated the effects of different resistance training (RT) volumes quantified by weekly sets at high intensity (load and effort) on dynamic strength adaptations and psychophysiological responses in trained individuals. Twenty-four athletes were randomly allocated to three groups that performed three (3 S, n=8), six (6 S, n=8), and nine (9 S, n=8) weekly sets, respectively, three times a week on the barbell back squat and bench press during an 8-week period. While all groups showcased strength gains (p<0.05), post hoc comparisons revealed that 6 S and 9 S elicited greater strength adaptations than 3 S in barbell back squat (p=0.027 and p=0.004, respectively) and bench press (p=0.001 and p=0.044, respectively). There were no differences between 6 S and 9 S conditions for back squat (p=0.999) and bench press (p=0.378). Although a time effect was observed for Session-RPE (p=0.014) and Total Quality Recovery scale (p=0.020), psychophysiological responses were similar among groups. Our findings suggest that performing six and nine weekly sets at high intensities led to greater strength gains compared to three weekly sets in strength-trained individuals, despite similar psychophysiological responses.


Asunto(s)
Adaptación Fisiológica , Fuerza Muscular , Entrenamiento de Fuerza , Humanos , Fuerza Muscular/fisiología , Entrenamiento de Fuerza/métodos , Masculino , Adulto Joven , Percepción/fisiología , Atletas , Levantamiento de Peso/fisiología , Adulto , Esfuerzo Físico/fisiología , Femenino
2.
Int J Sport Nutr Exerc Metab ; 34(3): 179-187, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38266627

RESUMEN

Despite the abundance of research investigating the efficacy of caffeine supplementation on exercise performance, the physiological and biochemical responses to caffeine supplementation during intermittent activities are less evident. This study investigated the acute effects of caffeine supplementation on measures of exercise performance, ratings of perceived exertion, and biomarkers of oxidative stress induced by an acute bout of sprint interval training. In a randomized crossover design, 12 healthy males (age: 26 ± 4 years, height: 177.5 ± 6 cm, body mass: 80.7 ± 7.6 kg) ingested 6 mg/kg of caffeine or placebo 60 min prior to performing sprint interval training (12 × 6 s "all-out sprints" interspersed by 60 s of rest). Performance scores and ratings of perceived exertion were assessed after every sprint. Blood samples were collected before supplementation, prior to and following each sprint, and 5 and 60 min after the last sprint. Caffeine had no effect on any performance measures, ratings of perceived exertion, or biomarkers of oxidative stress (p > .05). In conclusion, caffeine supplementation does not improve performance or decrease oxidative stress after an acute bout of sprint interval training.


Asunto(s)
Rendimiento Atlético , Entrenamiento de Intervalos de Alta Intensidad , Carrera , Adulto , Humanos , Masculino , Adulto Joven , Rendimiento Atlético/fisiología , Biomarcadores , Cafeína/farmacología , Estudios Cruzados , Método Doble Ciego , Estrés Oxidativo , Carrera/fisiología
3.
Med Sci Sports Exerc ; 56(3): 553-563, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-37796222

RESUMEN

PURPOSE: This study investigated the effect of progressively adding sets for the lower limb every 2 wk versus performing a constant set volume in resistance-trained males. METHODS: Thirty-one resistance-trained males (age = 24.4 ± 2.9 yr, height = 175.5 ± 6.5 cm, body mass = 80.1 ± 9.4 kg, body fat = 14.4% ± 3.1%, resistance training [RT] experience = 5.1 ± 2.2 yr; one-repetition maximum [1RM] barbell back squat: body mass ratio = 1.7 ± 0.1 a.u.) were randomly allocated into a constant group (CG, n = 10), a four-set progression group (4SG, n = 10) or a six-set progression group (6SG, n = 11). After a 2-wk washout period and another 2-wk familiarization period, participants performed a lower-limb training program twice a week for 12 wk. Maximum dynamic strength (1RM) in the barbell back squat, vastus lateralis cross-sectional area, and the sum of lateral thigh muscle thickness at 30%, 50%, and 70% of the femur length were assessed at baseline and after the 12-wk training program. RESULTS: Regarding 1RM, multiple comparisons revealed that 6SG elicited higher muscle strength gains than 4SG ( P = 0.002) and CG ( P < 0.0001), and 4SG had greater improvements than CG ( P = 0.023). Cross-sectional area and sum of lateral thigh muscle thickness showed no between-group differences ( P = 0.067 and P = 0.076, respectively). However, an inspection of 95% confidence intervals suggests a potential dose-response relationship, with results appearing to plateau in the higher volume conditions. CONCLUSIONS: Our results suggest that progressively adding four or six sets per week every 2 wk elicited greater lower-limb strength in resistance-trained individuals over a 12-wk training period. Although our findings indicate a possible small benefit for higher volume conditions regarding hypertrophic adaptations in this population, the limited certainty of our findings warrants caution.


Asunto(s)
Músculo Esquelético , Entrenamiento de Fuerza , Masculino , Humanos , Adulto Joven , Adulto , Músculo Esquelético/fisiología , Músculo Cuádriceps , Hipertrofia , Muslo , Fuerza Muscular/fisiología , Entrenamiento de Fuerza/métodos
4.
Percept Mot Skills ; 130(4): 1624-1643, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37197987

RESUMEN

We compared the effects of resistance training (ResisT) to pyramidal and traditional weightlifting sets on men's psychophysiological responses. In a randomized crossover design, 24 resistance-trained males performed drop-set, descending pyramid, and traditional ResisT in the barbell back squat, 45° leg press, and seated knee extension. We assessed participants' rating of perceived exertion (RPE) and feelings of pleasure/displeasure (FPD) at the end of each set and at 10, 15, 20, and 30 minutes post-session. No differences were detected across ResisT Methods in total training volume (p = 0.180). Post hoc comparisons revealed that drop-set training elicited higher RPE (M 8.8 SD 0.7 arbitrary units) and lower FPD (M -1.4 SD 1.5 arbitrary units) values compared to descending pyramid (M Set RPE 8.0 SD 0.9 arbitrary units and M Set FPD 0.4 SD 1.6 arbitrary units) and traditional set (M Set RPE 7.5 SD 1.1 arbitrary units and M Set FPD 1.3 SD 1.2 arbitrary units) schemes (p < 0.05). In addition, drop-set training elicited higher session RPE (M 8.1 SD 0.8 arbitrary units) and lower session FPD (M 0.2 SD 1.4 arbitrary units) values than descending pyramid and traditional ResisT (p < 0.001). Similarly, descending pyramid training elicited higher session RPE (M 6.6 SD 0.9 arbitrary units) and lower session FPD (M 1.2 SD 1.4 arbitrary units) than traditional set (M Session RPE 5.9 SD 0.8 arbitrary units and M Session FPD 1.5 SD 1.2 arbitrary units) training (p = 0.015). No differences were found in the temporality of post-session metrics, suggesting that testing 10 and 15 minutes post-ResisT was sufficient to assess session RPE (p = 0.480) and session FPD (p = 0.855), respectively. In conclusion, even with similar total training volume, drop-set training elicited more pronounced psychophysiological responses than either pyramidal or traditional ResisT in resistance-trained males.


Asunto(s)
Esfuerzo Físico , Entrenamiento de Fuerza , Masculino , Humanos , Esfuerzo Físico/fisiología , Entrenamiento de Fuerza/métodos , Ejercicio Físico , Levantamiento de Peso/fisiología , Placer
5.
Nutrients ; 14(22)2022 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-36432607

RESUMEN

The effects of acute caffeine supplementation on muscular strength remain unclear. We examined the effects of two different doses of caffeine on muscle strength and calcium in plasma compared to placebo using a crossover, randomized, double-blind, placebo-controlled design. Twenty-one (n = 21) recreationally resistance-trained participants were randomly assigned into three experimental conditions: 6 mg·kg bw−1 of caffeine (CF6); 8 mg·kg bw−1 of caffeine (CF8); or placebo (PLA), with a 7-day washout period between conditions. Muscular strength assessments were made for both upper (bench press) and lower body muscles (squat and deadlift). Calcium release in plasma was measured on five different occasions. Bench press (CF8: 100.1 ± 1.9 kg; PLA: 94.2 ± 2.5 kg), deadlift (CF8: 132.8 ± 3.5 kg; PLA: 120.7 ± 5.7 kg), and squat (CF8: 130.1 ± 4.9 kg; PLA 119.4 ± 5.4 kg) strength were all significantly (p < 0.001) improved in CF8 compared to PLA. Calcium release in plasma was significantly increased in CF8, whereas no changes were observed in CF6 or PLA. Overall, 8 mg·kg bw−1 of caffeine appears to be an effective dose to optimize upper and lower body muscular strength and calcium release in recreationally trained participants.


Asunto(s)
Cafeína , Calcio , Masculino , Humanos , Cafeína/farmacología , Calcio/farmacología , Fuerza Muscular , Calcio de la Dieta/farmacología , Poliésteres/farmacología
6.
Sports (Basel) ; 10(6)2022 May 24.
Artículo en Inglés | MEDLINE | ID: mdl-35736820

RESUMEN

This review aimed to analyze the findings in the literature related to Mixed Martial Arts (MMA) through an exploratory systematic review and to present the state of the art from a multifactorial perspective. The review was conducted in accordance with the PRISMA statement, with a search performed in the Scopus, PubMed, and Web of Science databases. Participants were competitive athletes (amateurs or professionals) of regional, national, or international levels. Of the 2763 registries identified, 112 studies met the eligibility criteria. The pooled sample size and age were 20,784 participants, with a mean age of 27.7 ± 6 years for male and 28.9 ± 3 years for female, with the vast majority of athletes being male (94.9%). MMA athletes were 17.2% amateurs, 73.8% professionals, and 9% were not reported. The scientific literature related to MMA reported injuries (n = 28), weight loss (n = 21), technical and tactical analysis (n = 23), physical fitness (n = 8), physiological responses and training characteristics (n = 13), psychobiological parameters (n = 12), and interventions applied to MMA athletes (n = 7). Therefore, this exploratory systematic review presents practitioners and researchers with seven broad summaries of each facet of performance of importance in this population of athletes.

7.
J Strength Cond Res ; 36(6): 1636-1642, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-32833890

RESUMEN

ABSTRACT: Zandona, BA, Ramos, RA, de Oliveira, CdS, McAnulty, SR, Ferreira, LHB, Smolarek, AC, Enes, AAN, Urbinati, KMdSS, Aragon, AA, Schoenfeld, BJ, and de Souza Junior, TP. Reduced Dose of Beta-Alanine Is Sufficient to Maintain Performance in Repeated Sprints. J Strength Cond Res 36(6): 1636-1642, 2022-Beta-alanine (BA) supplementation has been shown to be effective in improving physical performance by increasing carnosine concentration. However, it is still necessary to know the effect of a maintenance dose on performance. Thus, this study aimed to investigate the effects of a maintenance dose of BA supplementation on performance. Forty-four anaerobically trained men with 23.9 ± 3.8 years of age, 176.0 ± 0.05 cm height, 81.2 ± 7.5 kg body mass, and 15.5 ± 2.9% of body fat performed a cycle ergometer test consisting of 4 sprints of 30 s with 4 minutes of active recovery. The study comprised 3 phases: (a) presupplementation, (b) supplementation with 6.4 g·d-1 BA or placebo, and (c) postsupplementation with a maintenance dose of 1.2 g·d-1 of BA or interruption of supplementation. Data were analyzed using generalized estimated equations with a priori 0.05 level of significance. The placebo group and interruption group presented a lower power (7.28 ± 0.66 and 7.71 ± 0.42 W·kg-1 vs. 8.04 ± 0.84 and 9.25 ± 1.18 W·kg-1, respectively; p < 0.05) during the third sprint in postsupplementation, whereas the maintenance group maintained the required power (7.47 ± 1.03 vs. 8.74 ± 1.07 W·kg-1; p > 0.05). The placebo group also presented higher percentage of fatigue (44.5% ± 12.3 and 44.8% ± 7.7 vs. 37.6 ± 7.2%; p = 0.021) and higher subjective perception of exertion (8.92 ± 0.90 vs. 8.00 ± 1.60; p = 0.028). Therefore, the maintenance dose of 1.2 g·d-1 BA was effective in maintaining performance, whereas a reduction in performance was observed after supplementation interruption.


Asunto(s)
Rendimiento Atlético , Carnosina , Suplementos Dietéticos , Fatiga , Humanos , Masculino , beta-Alanina/farmacología
8.
Appl Physiol Nutr Metab ; 46(11): 1417-1424, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34260860

RESUMEN

This paper aimed to compare the effect of drop-set (DS) and rest-pause (RP) systems versus traditional resistance training (TRT) with equalized total training volume on maximum dynamic strength (1RM) and thigh muscle thickness (MT). Twenty-eight resistance-trained males were randomly assigned to either RP (n = 10), DS (n = 9) or TRT (n = 9) protocols performed twice a week for 8 weeks. 1RM and MT of the proximal, middle and distal portions of the lateral thigh were assessed at baseline and post-intervention. A significant time × group interaction was observed for 1RM (P = 0.001) in the barbell back squat after 8-weeks. Post hoc comparisons revealed that RP promoted higher 1RM than TRT (P = 0.001); no statistical differences in strength were observed between the other conditions. A significant main effect of time was revealed for MT at the proximal (P = 0.0001) and middle (P = 0.0001) aspects of the lateral thigh for all training groups; however, the distal portion did not show a time effect (P = 0.190). There were no between-group interactions for MT. Our findings suggest that RP promotes slightly superior strength-related improvements compared with TRT, but hypertrophic adaptations are similar between conditions. Novelty: Rest-pause elicited a slightly superior benefit for strength adaptations compared with traditional resistance training. Resistance training systems do not promote superior hypertrophic adaptations when total training volume is equalized. Muscle thickness in distal portion of thigh is similar to baseline. Although modest, effect sizes tended to favor rest-pause.


Asunto(s)
Adaptación Fisiológica , Fuerza Muscular/fisiología , Entrenamiento de Fuerza/métodos , Crecimiento del Músculo Esquelético , Adulto , Registros de Dieta , Humanos , Masculino , Músculo Esquelético/anatomía & histología , Músculo Esquelético/fisiología , Descanso , Muslo/anatomía & histología , Adulto Joven
9.
Nutrients ; 14(1)2021 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-35010928

RESUMEN

Sarcopenia is one of the main issues associated with the process of aging. Characterized by muscle mass loss, it is triggered by several conditions, including sedentary habits and negative net protein balance. According to World Health Organization, it is expected a 38% increase in older individuals by 2025. Therefore, it is noteworthy to establish recommendations to prevent sarcopenia and several events and comorbidities associated with this health issue condition. In this review, we discuss the role of these factors, prevention strategies, and recommendations, with a focus on protein intake and exercise.


Asunto(s)
Envejecimiento , Proteínas en la Dieta/administración & dosificación , Ejercicio Físico , Sarcopenia/prevención & control , Anciano , Anciano de 80 o más Años , Dieta/métodos , Femenino , Microbioma Gastrointestinal , Humanos , Estilo de Vida , Masculino , Fuerza Muscular , Músculo Esquelético/metabolismo , Estado Nutricional , Ingesta Diaria Recomendada , Conducta Sedentaria
10.
Rejuvenation Res ; 24(3): 191-197, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33115319

RESUMEN

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


Asunto(s)
Entrenamiento de Fuerza , Anciano , Brasil , Femenino , Humanos , Persona de Mediana Edad , Fuerza Muscular , Equilibrio Postural
11.
Physiol Genomics ; 53(2): 47-50, 2021 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-33346691

RESUMEN

Combat sports are an intermittent sport, with mixed anaerobic and aerobic energy production. Here, we investigated whether the polymorphisms that have been previously suggested as genetic markers for endurance or power phenotypes were associated with combat-sport athletic status. A total of 23 previously reported performance-related polymorphisms were examined in a cohort of 1,129 Brazilian individuals (164 combat-sport athletes and 965 controls), using a case-control association study. We found that the GA-binding protein transcription factor subunit beta 1 (GABPß1) gene (also known as nuclear respiratory factor 2; NRF2) was associated with athletic status, with the minor G (rs7181866) and T (rs8031031) alleles overrepresented in athletes (P ≤ 0.003), especially among world-class athletes (P ≤ 0.0002). These findings indicate that single-nucleotide polymorphisms (SNPs) within the GABPß1 gene increase the likelihood of an individual being a combat-sport athlete, possibly because of a better mitochondrial response to intermittent exercises.


Asunto(s)
Atletas , Factor de Transcripción de la Proteína de Unión a GA/genética , Resistencia Física/genética , Polimorfismo de Nucleótido Simple , Adolescente , Adulto , Alelos , Brasil , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Frecuencia de los Genes , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Adulto Joven
12.
Sports (Basel) ; 8(11)2020 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-33218168

RESUMEN

Bodybuilding is a sport that requires adequate training strategies in order to maximize skeletal muscle hypertrophy. The purpose of the present review was to perform a narrative assessment of the training routines designed for muscle hypertrophy used by bodybuilders. A search was carried out in the databases Pubmed/MEDLINE, Scielo, EBSCO, LILACS, SportDiscus, Web of Science, and CINAHL with the words "Resistance training" and "hypertrophy" in bodybuilders and their variations that involve the respective outcomes. Fourteen studies were identified that investigated the long-term training routines of bodybuilders. These studies demonstrate a pattern in the training organization, whereby there is a separation of training into four distinct periods: off-season, pre-contest, peak week, and post-contest. Each period has a specific spectrum of intensity load, total training volume, and exercise type (multi- or single-joint). We conclude that bodybuilding competitors employed a higher intensity load, lower number of repetitions, and longer rest intervals in the off-season than pre-contest.

13.
J Hum Kinet ; 70: 115-124, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31915481

RESUMEN

The objective of the study was to characterize immunological responses to a Brazilian Jiu-Jitsu high-intensity interval training session. Neuromuscular function, blood, and salivary samples were obtained after a Brazilian Jiu-Jitsu high-intensity interval training session. Saliva and blood samples were collected at Pre- (before the warm-up) and immediately Post-training. Neuromuscular function was evaluated by lower body muscle testing. The horizontal countermovement jump was performed at Pre (after the warm-up) and immediately Post blood and saliva collection, and approximately 5 minutes Post-training. The horizontal countermovement jump performance did not present any significant changes Post-training, while blood leukocytes, urea, IgA and salivary alpha-amylase showed a significant increase. Salivary alpha-amylase activity increased more than six times immediately Post compared to Pre-training. Saliva volume, secretion rate, and uric acid were not significantly different between Pre and Post condition. A Brazilian Jiu-Jitsu high-intensity interval training session elicited an increase in the blood cells responsible for antibody production and muscle damage adaptation after exercise. On the other hand, neuromuscular performance was not significantly affected Post-training, suggesting that immunological and performance responses were not necessarily associated.

14.
Conscientiae saúde (Impr.) ; 17(3): 293-301, set. 2018.
Artículo en Portugués | LILACS | ID: biblio-965056

RESUMEN

Introdução: Atualmente, vem crescendo a utilização de diferentes métodos de treinamento de força (TF) como drop-set e bi-set, com intuito de maximizar gasto energético (GE). Porém, não há evidências que comprovem este fato. Objetivos: Mensurar e comparar o gasto energético (GE) em sessões de TF empregando os métodos drop-set, bi-set e TF tradicional (TRAD). Métodos: Nove homens recreacionalmente ativos realizaram três protocolos de exercícios em dias distintos, separados por intervalos de uma semana. O drop-set e o TRAD seguiram ordem fixa de execução dos exercícios; o bi-set foi realizado com dois exercícios sem intervalo entre eles. Todos os protocolos foram desempenhados a 80% de 1RM e, durante as sessões de treinamento, foi mensurado o consumo de oxigênio (VO2) e o GE. Resultados: Os resultados indicam que, durante a sessão de treino, o método drop-set gerou maiores valores de VO2 (13,6 ± 6,8 > 11,2 ± 5,9 kg/ml/min), GE (5,2 ± 2,3 > 4,5 ± 2,3 kcal/min -1), frequência cardíaca (128 ± 27,1 > 113 ± 22,4 bpm -1) e razão de trocas gasosas (1,2 ± 0,2 > 1,1 ± 0,1) quando comparado ao bi-set e TRAD (p<0,05). Conclusão: Maiores valores de frequência cardíaca durante o treino e gasto calórico superior foram observados no TF realizado com o método drop-set em relação ao bi-set e TRAD.


Introduction: It is currently growing use of different strength training methods (ST) as a drop-set and bi-set, in order to maximize energy expenditure (EE). However, there is no evidence to prove this fact. Objective: The aim of this study was to compare the EE of training sessions of methods drop-set, bi-set and traditional ST (TRAD). Methods: Nine men recreationally assets had performed three protocols of exercises on different days separated by a break of week between each. The drop-set and the TRAD followed a fixed order of the exercises; the bi-set were two exercises without a break followed the other, forming combinations which were: squat-flexor and extensor chair - plantar flexion. All protocols were performed at 80% of 1RM and during the training sessions were measured oxygen consumption and the calorie expenditure. Results: The results indicate during the training session the drop-set promoted higher values of VO2 (13.6 ± 6.8> 11.2 ± 5.9 kg / ml / min), EE (5.2 ± 2.3 ± 4.5 ± 2.3 kcal / min-1), heart rate (128 ± 27.1> 113 ± 22.4 bpm-1) and gas exchange ratio (1.2 ± 0.2> 1.1 ± 0.1) when compared to bi-set and TRAD (p<0.05). Conclusion: Briefly, the incorporation of the protocol drop-set can benefit the practitioners that aim at maximizing the consumption of EE.


Asunto(s)
Humanos , Masculino , Adolescente , Adulto , Adulto Joven , Metabolismo Energético , Entrenamiento de Fuerza/métodos , Estudios Transversales
15.
Artículo en Inglés | MEDLINE | ID: mdl-28190980

RESUMEN

BACKGROUND: To determine the effects of a low dose, short-term Creatine monohydrate (Cr) supplementation (0.03 g.kg.d-1 during 14 d) on muscle power output in elite youth soccer players. METHODS: Using a two-group matched, double blind, placebo-controlled design, nineteen male soccer players (mean age = 17.0 ± 0.5 years) were randomly assigned to either Cr (N = 9) or placebo (N = 10) group. Before and after supplementation, participants performed a 30s Wingate Anaerobic Test (WAnT) to assess peak power output (PPO), mean power output (MPO), fatigue index (FI), and total work. RESULTS: There were significant increases in both PPO and MPO after the Cr supplementation period (P ≤ 0.05) but not the placebo period. There were also significant increases in total work, but not FI, after the Cr supplementation and placebo periods (P ≤ 0.05). Notably, there were differences in total work between the Cr and placebo groups after (P ≤ 0.05) but not before the 14 d supplementation period. CONCLUSION: There is substantial evidence to indicate that a low-dose, short-term oral Cr supplementation beneficially affected muscle power output in elite youth soccer players.


Asunto(s)
Creatina/administración & dosificación , Suplementos Dietéticos , Músculo Esquelético/fisiología , Fútbol , Adolescente , Creatina/farmacología , Método Doble Ciego , Humanos , Masculino , Músculo Esquelético/efectos de los fármacos , Resistencia Física/efectos de los fármacos , Fenómenos Fisiológicos en la Nutrición Deportiva , Análisis y Desempeño de Tareas
16.
Clin Interv Aging ; 11: 749-54, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27330282

RESUMEN

Aging is a degenerative process marked by recognized functional, physiological, and metabolic impairments, such as dynapenia and diminished cognitive capacity. Therefore, the search for innovative strategies to prevent/delay these physiological and cognitive disorders is essential to guarantee the independence and life quality of an elderly population. The aim of this work is to verify the effect of a 12-week resistance exercise program on the general physical aptitude and cognitive capacities of elderly and sedentary women. Twenty-nine women (65.87±5.69 years) were divided into two groups. The control group was composed of eight elderly women who met the same inclusion criteria of the study and the strength training group was composed of 29 elderly women who were subjected to a resistance exercise program defined by 12 upper and lower limb exercises combined in 3×10 repetitions with 1-minute interval between repetitions and two resting minutes between exercises (three times/week). Weight loads were fixed between 60% and 75% of the apparent 1 repetition maximum, which was estimated by the test of 10 maximum repetitions. The direct curl was performed for upper body strength evaluation with 2.3 kg dumbbells for 30 seconds, whereas the chair test was used for lower body evaluation (total sit-stand movements in 30 seconds). The cognitive capacities of subjects were evaluated by "The Montreal Cognitive Assessment" questionnaire. After 12 weeks, the elderly group showed significant increases in the average upper body strength (58%), lower body strength (68%), and cognitive capacity (19%). The present study demonstrated that regular resistance exercises could provide significant gains on the upper and lower body strength concomitant to positive improvements on cognitive capacities of elderly women, bringing enhanced life quality.


Asunto(s)
Envejecimiento/psicología , Cognición , Fuerza Muscular , Entrenamiento de Fuerza/métodos , Anciano , Brasil , Femenino , Humanos , Modelos Logísticos , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica
17.
J Aging Res ; 2014: 749317, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24834354

RESUMEN

The rating of perceived exertion (RPE) is ability to detect and interpret organic sensations while performing exercises. This method has been used to measure the level of effort that is felt during weight-training at a given intensity. The purpose of this investigation was to compare session RPE values with those of traditional RPE measurements for different weight-training muscle actions, performed together or separately. Fourteen women with no former weight-training experience were recruited for the investigation. All participants completed five sessions of exercise: familiarization, maximum force, concentric-only (CONC-only), eccentric-only (ECC-only), and dynamic (DYN = CONC + ECC). The traditional RPE method was measured after each series of exercises, and the session RPE was measured 30 min after the end of the training session. The statistical analyses used were the paired t-test, one-way analysis of variance, and repeated measures analysis of variance. Significant differences between traditional RPE and session RPE for DYN, CONC, and ECC exercises were not found. This investigation demonstrated that session RPE is similar to traditional RPE in terms of weight-training involving concentric, eccentric, or dynamic muscle exercises, and that it can be used to prescribe and monitor weight-training sessions in older subjects.

18.
J Int Soc Sports Nutr ; 9(1): 25, 2012 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-22691230

RESUMEN

BACKGROUND: Dietary creatine has been largely used as an ergogenic aid to improve strength and athletic performance, especially in short-term and high energy-demanding anaerobic exercise. Recent findings have also suggested a possible antioxidant role for creatine in muscle tissues during exercise. Here we evaluate the effects of a 1-week regimen of 20 g/day creatine supplementation on the plasma antioxidant capacity, free and heme iron content, and uric acid and lipid peroxidation levels of young subjects (23.1 ± 5.8 years old) immediately before and 5 and 60 min after the exhaustive Wingate test. RESULTS: Maximum anaerobic power was improved by acute creatine supplementation (10.5 %), but it was accompanied by a 2.4-fold increase in pro-oxidant free iron ions in the plasma. However, potential iron-driven oxidative insult was adequately counterbalanced by proportional increases in antioxidant ferric-reducing activity in plasma (FRAP), leading to unaltered lipid peroxidation levels. Interestingly, the FRAP index, found to be highly dependent on uric acid levels in the placebo group, also had an additional contribution from other circulating metabolites in creatine-fed subjects. CONCLUSIONS: Our data suggest that acute creatine supplementation improved the anaerobic performance of athletes and limited short-term oxidative insults, since creatine-induced iron overload was efficiently circumvented by acquired FRAP capacity attributed to: overproduction of uric acid in energy-depleted muscles (as an end-product of purine metabolism and a powerful iron chelating agent) and inherent antioxidant activity of creatine.

19.
J Int Soc Sports Nutr ; 8(1): 17, 2011 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-22032491

RESUMEN

BACKGROUND: The purpose of the current study was to compare strength and hypertrophy responses to resistance training programs that instituted constant rest intervals (CI) and decreasing rest intervals (DI) between sets over the course of eight weeks by trained men who supplemented with creatine monohydrate (CR). METHODS: Twenty-two recreationally trained men were randomly assigned to a CI group (n = 11; 22.3 ± 1 years; 77.7 ± 5.4 kg; 180 ± 2.2 cm) or a DI group (n = 11; 22 ± 2.5 years; 75.8 ± 4.9 kg; 178.8 ± 3.4 cm). Subjects in both groups supplemented with CR; the only difference between groups was the rest interval instituted between sets; the CI group used 2 minutes rest intervals between sets and exercises for the entire 8-weeks of training, while the DI group started with a 2 minute rest interval the first two weeks; after which the rest interval between sets was decreased 15 seconds per week (i.e. 2 minutes decreasing to 30 seconds between sets). Pre- and post-intervention maximal strength for the free weight back squat and bench press exercises and isokinetic peak torque were assessed for the knee extensors and flexors. Additionally, muscle cross-sectional area (CSA) of the right thigh and upper arm was measured using magnetic resonance imaging. RESULTS: Both groups demonstrated significant increases in back squat and bench press maximal strength, knee extensor and flexor isokinetic peak torque, and upper arm and right thigh CSA from pre- to post-training (p ≤ 0.0001); however, there were no significant differences between groups for any of these variables. The total volume for the bench press and back squat were significantly greater for CI group versus the DI group. CONCLUSIONS: We report that the combination of CR supplementation and resistance training can increase muscular strength, isokinetic peak torque, and muscle CSA, irrespective of the rest interval length between sets. Because the volume of training was greater for the CI group versus the DI group, yet strength gains were similar, the creatine supplementation appeared to bolster adaptations for the DI group, even in the presence of significantly less volume. However, further research is needed with the inclusion of a control group not receiving supplementation combined and resistance training with decreasing rest intervals to further elucidate such hypotheses.

20.
Rev. bras. farmacogn ; 21(2): 283-289, mar.-abr. 2011. graf, tab
Artículo en Inglés | LILACS | ID: lil-590193

RESUMEN

Astaxanthin (ASTA) is a pinkish-orange carotenoid produced by microalgae, but also commonly found in shrimp, lobster and salmon, which accumulate ASTA from the aquatic food chain. Numerous studies have addressed the benefits of ASTA for human health, including the inhibition of LDL oxidation, UV-photoprotection and prophylaxis of bacterial stomach ulcers. ASTA is recognized as a powerful scavenger of reactive oxygen species (ROS), especially those involved in lipid peroxidation. Both aerobic and anaerobic exercise are closely related to overproduction of ROS in muscle tissue. Post-exercise inflammatory processes can even exacerbate the oxidative stress imposed by exercise. Thus, ASTA is suggested here as a putative nutritional alternative/coadjutant for antioxidant therapy to afford additional protection to muscle tissues against oxidative damage induced by exercise, as well as for an (overall) integrative redox re-balance and general human health.

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