RESUMO
BACKGROUND: Sambo is a martial art and combat sport that originated in the Soviet Union. There are two main stiles, Sport Sambo and Combat Sambo which resembles modern mixed martial arts. Very little literature is available about physiological aspects of Sambo and, in particular, on the possible effects on cognitive domains. The purpose of the present research was to determine if there is a correlation between a blood lactate increase and the intensity and/or selectivity of attentions. METHODS: Sixteen male athletes practicing Sambo for at least 5 years participated voluntarily in the study. Each athlete had to sustain, with an interval of one week, both a Sport Sambo match and a Combat Sambo match, each lasting 5 min. Blood lactate levels as well as attentive capacities were evaluated at three different times: at rest, i.e., 5 min before the start of the session (pre), at end of the session and 15 min after its conclusion. Reaction time protocol was used to evaluate the intensity of attention, whereas divided attention was assessed for analyzing the selectivity of attention together with errors and omissions. RESULTS: Concerning Sport Sambo, blood lactate was 1.66 mmol/L (±0.55 SD) before the session, reached a mean value of 3.40 mmol/L (±0.45 SD) at the end of the session (end) and returned to values similar to initial ones (a mean value of 1.98 mmol/L (±0.37 SD) after 15 min (15-end). None of the attentive parameters examined, showed statistically significant differences. Conversely, for Combat Sambo, it was found a significant increase in blood lactate levels that went from 1.66 mmol/L (±0.55 SD) before the session (pre), to 4.76 mmol/L (±0.60 SD) at the end (end) and then back to values similar to those observed before the session 15 min after its conclusion (15-end), i.e., 1.97 mmol/L (±0.37 SD); however, after a Combat Sambo session increases in blood lactate were associated with significant worsening of attentional mechanisms. CONCLUSIONS: In conclusion, in all the participants, the worsening of attentional mechanisms was observed only after the Combat Sambo session in which blood lactate values exceeded 4 mmol/L. This figure, also known as the Onset of Blood Lactate Accumulation (OBLA), is commonly used to determine the anaerobic threshold.
Assuntos
Artes Marciais , Limiar Anaeróbio/fisiologia , Atletas , Atenção , Humanos , Lactatos , Masculino , Artes Marciais/fisiologiaRESUMO
BACKGROUND: Fish oils were studied as ergogenic aids in a number of mixed physical trial designs showing promising results. However, the heterogeneous purity of the studied supplements, combined with the variety of physical tests employed call for more studies to confirm these findings, ideally with standardised supplements. Our aim was to test a supplement highly concentrated in DHA (DHA:EPA ratio equal to approximately 8:1) on a maximal cycling test to elucidate performance improvements mainly due to DHA. METHODS: A double-blind, placebo controlled, randomised balanced, parallel design, in competitive amateur cyclists was employed. They were all male, older than 18 years old, with training routine of 2 to 4 sessions per week lasting at least one hour each. A ramp cycling test to exhaustion with a subsequent 5 min recovery phase was employed before and after treatment to analyse aerobic metabolism and lactate clearance after the bout. After 30 days of supplementation with 975 mg of re-esterified DHA, the thirty-eight cyclist who completed the study were finally included for statistical analysis. RESULTS: Mean power output at ventilatory threshold 2 (VT2) improved after DHA supplementation both as absolute (â³DHA versus â³PLA: 6.33-26.54 Watts; CI 95%) and relative (p=0.006) values, paralleled with higher oxygen consumption at VT2 both for absolute (DHA 2729.4 ±304.5, 3045.9 ±335.0; PLA 2792.3 ±339.5, 2845.5 ±357.1; ml·min-1 baseline versus post p=0.025) and relative values (DHA 36.6 ±5.0, 41.2 ±5.4; PLA 37.2 ±5.7, 38.1 ±5.2; ml·kg-1·min-1 baseline versus post p=0.024). Heart rate recovery rate improved during the recovery phase in the DHA group compared to PLA (p=0.005). CONCLUSION: DHA is capable of improving mean power output at the ventilatory threshold 2 (anaerobic ventilatory threshold) in amateur competitive cyclists. It is unclear if these findings are the result of the specific DHA supplement blend or another factor.
Assuntos
Limiar Anaeróbio/fisiologia , Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Comportamento Competitivo/fisiologia , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Substâncias para Melhoria do Desempenho/administração & dosagem , Adulto , Ácidos Docosa-Hexaenoicos/metabolismo , Método Duplo-Cego , Esterificação , Frequência Cardíaca , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio , Substâncias para Melhoria do Desempenho/metabolismoRESUMO
Mixed Martial Arts (MMA) is a multielement combat sport where fighters need to quickly react to an opponent's movements under fatigued conditions. Research indicates that fast reaction time is important in many sports, but the effect of fatigue has shown negative, null, or even positive influences on reaction time. However, few studies have been conducted in a controlled setting, especially using MMA figthers, whose matches are frequently resolved in a split-second. Therefore, this study investigated whether acute neuromuscular fatigue affects reaction and movement times, and their consistency in MMA fighters (N = 45). Before and after an upper-body Wingate test, a simple visual reaction time task was completed. Results showed a significant negative effect of fatigue on the reaction times and their consistency, with longer reactions (1.5% change) and lower consistency (14.7% change) after the Wingate test. Further, greater amounts of fatigue during the Wingate test seemed to negatively affect the consistency of post-Wingate movement time. Due to cumulative fatigue and the dynamic nature of MMA, our data indicate that not only the decrements in aerobic and anaerobic power likely affect a fighter's performance, but their reaction time and motor time may also be compromised during a fight.
Assuntos
Artes Marciais/fisiologia , Fadiga Muscular/fisiologia , Tempo de Reação/fisiologia , Adolescente , Adulto , Limiar Anaeróbio/fisiologia , República Tcheca , Humanos , Masculino , Adulto JovemRESUMO
The aim of this study was the assessment of progressive low-dose sodium bicarbonate (NaHCO3) supplementation on the anaerobic indices in two bouts of Wingate tests (WT) separated by wrestling-specific performance test and assessing the gender differences in response. Fifty-one (18 F) wrestlers completed a randomized trial of either a NaHCO3 (up to 100 mg·kg-1) or a placebo for 10 days. Before and after treatment, athletes completed an exercise protocol that comprised, in sequence, the first WT1, dummy throw test (DT), and second WT2. The number of completed throws increased significantly in males from 19.3 ± 2.6 NaHCO3pre to 21.7 ± 2.9 NaHCO3post. ΔWT2-WT1 improved particularly in the midsection of 30-s WT on NaHCO3. However, no significant differences were found in peak power (PP), power drop (PD) and average power (AP) (analyzed separately for each WT), and ΔWT2-WT1 in PP and PD. Interaction with gender was significant for AP, PP and PD, every second of WT1 and WT2, as well as DT test. In conclusion, our study suggests that the response to NaHCO3 may be gender-specific and progressive low-dose NaHCO3 supplementation allows the advantageous strengthening of wrestling-specific performance in males. It can also lead to maintenance of high anaerobic power mainly in the midsection of the 30-s Wingate test.
Assuntos
Limiar Anaeróbio/efeitos dos fármacos , Desempenho Atlético/fisiologia , Suplementos Nutricionais , Bicarbonato de Sódio/administração & dosagem , Luta Romana/fisiologia , Adolescente , Limiar Anaeróbio/fisiologia , Atletas , Teste de Esforço/efeitos dos fármacos , Feminino , Humanos , Masculino , Fatores Sexuais , Adulto JovemRESUMO
BACKGROUND: The aim of this study was to determine the relative and absolute test-retest reliability and criterion validity of a new Taekwondo Anaerobic Intermittent Kick Test (TAIKT). METHODS: Twenty Tunisian elite Taekwondo athletes participated in this study (15 males and 5 females). Participants performed the TAIKT and the Running-based Anaerobic Sprint Test (RAST), twice (test and retest), on separate occasions three-week apart. Peak heart rate (HRpeak), blood lactate concentration [LaÖ¾], and rating of perceived exertion (RPE) were measured during each session. RESULTS: There was no significant difference between the test and retest of TAIKT and RAST for all performances and physiological variables, except for the absolute mean power (Pmean) of RAST. Test-retest results showed that the TAIKT and RAST were reliable. All TAIKT and RAST parameters had an ICC>0.90, SEM<5%, with the smallest worthwhile change slightly higher than SEM, with very small limits of concordance. Strong significant correlations were found between TAIKT and RAST parameters (Ppeak (r=0.81; r=0.70), Pmean (r=0.72; r=0.60) in (W and W·Kg-67 respectively), fatigue index (r=0.81), [LaÖ¾] (r=0.89) and RPE (r=0.78) at P<0.01, and HRpeak (r=0.55, at P<0.05)). CONCLUSIONS: The findings showed that the TAIKT can be considered as a valid and reliable specific test for assessing anaerobic power of Taekwondo athletes.
Assuntos
Limiar Anaeróbio/fisiologia , Teste de Esforço/normas , Corrida/fisiologia , Feminino , Frequência Cardíaca/fisiologia , Humanos , Ácido Láctico/sangue , Masculino , Artes Marciais/fisiologia , Reprodutibilidade dos TestesRESUMO
PURPOSE: To determine the effect of dietary nitrate (NO3-) supplementation on physiology and performance in well-trained cyclists after 6-8 d of NO3- supplementation. METHODS: Eight competitive male cyclists (mean ± SD age 26 ± 8 y, body mass 76.7 ± 6.9 kg, VO2peak 63 ± 4 mL · kg-1 · min-1) participated in a double-blind, placebo-controlled, crossover-design study in which participants ingested 70 mL of beetroot juice containing ~4 mmol NO3- (NIT) or a NO3--depleted placebo (PLA), each for 8 d. Replicating pretreatment measures, participants undertook an incremental ramp assessment to determine VO2peak and first (VT1) and second (VT2) ventilatory thresholds on d 6 (NIT6 and PLA6), moderate-intensity cycling economy on d 7 (NIT7 and PLA7), and a 4-km time trial (TT) on d 8 (NIT8 and PLA8). RESULTS: Relative to PLA, 6 d of NIT supplementation produced unclear effects for VO2peak (mean ± 95% confidence limit: 1.8% ± 5.5%) and VT1 (3.7% ± 12.3%) and trivial effects for both VT2 (-1.0% ± 3.0%) and exercise economy on d 7 (-1.0% ± 1.6%). However, effects for TT performance time (-0.7% ± 0.9%) and power (2.4% ± 2.5%) on d 8 were likely beneficial. CONCLUSIONS: Despite mostly unclear outcomes for standard physiological determinants of performance, 8 d of NO3- supplementation resulted in likely beneficial improvements to 4-km TT performance in well-trained male endurance cyclists.
Assuntos
Desempenho Atlético/fisiologia , Ciclismo/fisiologia , Suplementos Nutricionais , Nitratos/administração & dosagem , Adulto , Limiar Anaeróbio/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Metabolismo Energético/fisiologia , Sucos de Frutas e Vegetais , Humanos , Masculino , Nitratos/sangue , Consumo de Oxigênio/fisiologia , Condicionamento Físico HumanoRESUMO
BACKGROUND: Skeletal muscle adenosine triphosphate (ATP) levels are severely depleted during and following prolonged high intensity exercise. Recovery from these lower ATP levels can take days, which can affect performance on subsequent days of exercise. Untrained individuals often suffer the stress and consequences of acute, repeated bouts of exercise by not having the ability to perform or recovery sufficiently to exercise on subsequent days. Conversely, trained individuals may be able to recover more quickly due to their enhanced metabolic systems. D-Ribose (DR) has been shown to enhance the recovery in ATP; however, it is not known if recovery and performance can be benefitted with DR ingestion. Therefore, this study was designed to determine what influence DR might have on muscular performance, recovery, and metabolism during and following a multi-day exercise regimen. METHODS: The study was a double blind, crossover study in 26 healthy subjects compared 10 g/day of DR to 10 g/day of dextrose (DEX, control). All subjects completed 2 days of loading with either DR or DEX, followed by 3 additional days of supplementation and during these 3 days of supplementation, each subject underwent 60 min of high intensity interval exercise in separate daily sessions, which involved cycling (8 min of exercise at 60% and 2 min at 80% VO2max), followed by a 2 min power output (PO) test. Subjects were divided into two groups based on peak VO2 results, lower VO2 (LVO2) and higher peak VO2 (HVO2). RESULTS: Mean and peak PO increased significantly from day 1 to day 3 for the DR trial compared to DEX in the LVO2 group. Rate of perceived exertion (RPE) and creatine kinase (CK) were significantly lower for DR than DEX in the LVO2 group. No differences in PO, RPE, heart rate, CK, blood urea nitrogen, or glucose were found between either supplement for the HVO2 group. CONCLUSION: DR supplementation in the lower VO2 max group resulted in maintenance in exercise performance, as well as lower levels of RPE and CK. Unlike no observed benefits with DEX supplementation.
Assuntos
Trifosfato de Adenosina/metabolismo , Limiar Anaeróbio/efeitos dos fármacos , Desempenho Atlético/fisiologia , Suplementos Nutricionais , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Aptidão Física/fisiologia , Ribose/farmacologia , Adulto , Limiar Anaeróbio/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Metabolismo Energético/efeitos dos fármacos , Feminino , Humanos , Masculino , Fenômenos Fisiológicos da Nutrição EsportivaRESUMO
PURPOSE: The purpose of the present investigation was to study the metabolic demand and cardiovascular response during a typical horse riding session. METHODS: To this aim, 19 (9 male, 10 female) riders, regularly participating in competitions, were enrolled. They underwent a preliminary, incremental exercise test on a cycle-ergometer to assess their anaerobic threshold (AT) and VO2max. Then, participants underwent a riding training session, which comprised periods of walking, trotting, and cantering for a total of 20 min. Oxygen uptake (VO2), carbon dioxide production (VCO2), and heart rate (HR) were obtained throughout the preliminary and riding test by means of a portable metabolic system. Moreover, excess of CO2 production (CO2excess) and oxygen pulse (OP) were also calculated to obtain an estimate of anaerobic glycolysis and stroke volume. RESULTS: The main result was that all collected parameters remained below the AT level throughout the riding session, with the exception of HR that approached the AT level only during cantering. In detail, during cantering, average VO2, VCO2, HR, CO2excess, and OP values were 1289 ± 331 mL min(-1), 1326 ± 266 mL min(-1), 158 ± 22 bpm, 215 ± 119 mL min(-1), and 7.8 ± 1.6 mL/bpm, respectively. CONCLUSIONS: It was concluded that riding imposes only light to moderate stress on the aerobic and anaerobic energy systems. Moreover, cardiovascular reserve is only moderately recruited in terms of inotropism, while chronotropism can be stimulated more.
Assuntos
Limiar Anaeróbio/fisiologia , Frequência Cardíaca/fisiologia , Cavalos , Consumo de Oxigênio/fisiologia , Troca Gasosa Pulmonar/fisiologia , Esportes/fisiologia , Animais , Metabolismo Energético/fisiologia , Terapia Assistida por Cavalos/métodos , Feminino , Humanos , Masculino , Esforço Físico/fisiologia , Aptidão Física/fisiologia , Análise e Desempenho de TarefasRESUMO
BACKGROUND: Consumption of pre-workout dietary supplements by both recreational and competitive athletes has increased dramatically in recent years. The purpose of this study was to determine the acute effects of a caffeine-containing pre-workout dietary supplement on various measures of performance including anaerobic power, upper and lower body power, and upper body strength in recreationally trained males. METHODS: Thirteen males (mean ± SD age = 24 ± 6 yrs; height = 180.3 ± 5 cm; body mass = 83.4 ± 9 kg) participated in this investigation in which they reported to the laboratory on four separate occasions, each separated by one week. Each subject underwent an initial familiarization session on week one followed by baseline (BA) performance testing on week two. Performance testing included a medicine ball put (MBP) to determine upper body explosive power, vertical jump test (VJ) to determine lower body explosive power, one-rep maximum bench press (1-RM) for determining upper body strength, and a Wingate Anaerobic Power Test (WAnT) to determine measures of anaerobic power. On week three, subjects were randomly assigned to ingest either a pre-workout supplement (SUP) or a placebo (PL) and again complete the performance testing protocol. Subjects were provided with the crossover treatment on the fourth and final week. Performance testing commenced 20-minute following ingestion of both treatments, which was similar to previous investigations. RESULTS: Significant differences in anaerobic peak power relative to the WAnT were observed following ingestion of the SUP (782 ± 191 W) in comparison to the PL (722 ± 208 W; p = 0.003; effect size = 0.30) and BA (723 ± 205 W; p = 0.011; effect size = 0.28). Significant differences were also observed for anaerobic mean power following ingestion of the SUP (569 ± 133 W) in comparison to the PL (535 ± 149 W; p = 0.006; effect size = 0.24) and BA (538 ± 148 W; p = 0.020; effect size = 0.22). No significant differences between trials were observed for upper body power, lower body power, or upper body strength. CONCLUSIONS: Ingestion of the pre-workout dietary supplement led to significant improvements in anaerobic peak and mean power values in comparison to the placebo and baseline treatments. No improvements were observed in upper and lower body power or upper body strength. Taken prior to exercise, a caffeine-containing pre-workout dietary supplement may improve anaerobic power performance.
Assuntos
Limiar Anaeróbio/fisiologia , Suplementos Nutricionais , Alimentos Formulados , Força Muscular/fisiologia , Resistência Física/fisiologia , Treinamento Resistido , Limiar Anaeróbio/efeitos dos fármacos , Estudos Cross-Over , Método Duplo-Cego , Exercício Físico , Humanos , Masculino , Força Muscular/efeitos dos fármacos , Músculo Esquelético/fisiologia , Resistência Física/efeitos dos fármacos , Fenômenos Fisiológicos da Nutrição Esportiva , Adulto JovemRESUMO
BACKGROUND: Phosphatidic acid (PA) is a lipid messenger that has been shown to increase muscle protein synthesis via signaling stimulation of the mammalian target of rapamycin (mTOR). MaxxTOR® (MT) is a supplement that contains PA as the main active ingredient but also contains other synergistic mTOR signaling substances including L-Leucine, Beta-Hydroxy-Beta-Methylbutyrate (HMB), and Vitamin D3. METHODS: Eighteen healthy strength-trained males were randomly assigned to a group that either consumed MT (n = 8, 22.0 +/- 2.5 years; 175.8 +/- 11.5 cm; 80.3 +/- 15.1 kg) or a placebo (PLA) (n = 10, 25.6 +/- 4.2 years; 174.8 +/- 9.0 cm; 88.6 +/- 16.6 kg) as part of a double-blind, placebo controlled pre/post experimental design. All participants volunteered to complete the three day per week resistance training protocol for the eight week study duration. To determine the effects of MT, participants were tested on one repetition maximum (1RM) leg press strength (LP), 1RM bench press strength (BP), push-ups to failure (PU), vertical jump (VJ), pro-agility shuttle time (AG), peak power output (P), lean body mass (LBM), fat mass (FM), and thigh muscle mass (TMM). Subjects were placed and monitored on an isocaloric diet consisting of 25 protein, 50 carbohydrates, and 25 % fat by a registered dietitian. Separate two-way mixed factorial repeated measures ANOVA's (time [Pre, Post] x group [MT and PLA] were used to investigate strength, body composition, and other performance changes. Post-hoc tests were applied as appropriate. Analysis were performed via SPSS with significance at (p ≤ 0.05). RESULTS: There was a significant main effect (F(1,16) = 33.30, p < 0.001) for LBM where MT significantly increased LBM when compared to the PLA group (p < 0.001). Additionally, there was a significant main effect for LP (F(1,16) = 666.74, p < 0.001) and BP (F(1,16) = 126.36, p < 0.001) where both increased significantly more in MT than PLA group (p < 0.001). No significant differences between MT and PLA were noted for FM, TMM, VJ, AG, P, or PU. CONCLUSION: The results of this eight week trial suggest that the addition of MaxxTOR® to a 3-day per week resistance training program can positively impact LBM and strength beyond the results found with exercise alone.
Assuntos
Limiar Anaeróbio/efeitos dos fármacos , Composição Corporal/efeitos dos fármacos , Suplementos Nutricionais , Força Muscular/efeitos dos fármacos , Ácidos Fosfatídicos/farmacologia , Resistência Física/efeitos dos fármacos , Treinamento Resistido , Adulto , Limiar Anaeróbio/fisiologia , Composição Corporal/fisiologia , Método Duplo-Cego , Alimentos Formulados , Humanos , Masculino , Força Muscular/fisiologia , Músculo Esquelético/fisiologia , Fenômenos Fisiológicos da Nutrição Esportiva , Serina-Treonina Quinases TOR/metabolismo , Resultado do Tratamento , Levantamento de PesoRESUMO
BACKGROUND: Creatine monohydrate (CrM) and nitrate are popular supplements for improving exercise performance; yet have not been investigated in combination. We performed two studies to determine the safety and exercise performance-characteristics of creatine nitrate (CrN) supplementation. METHODS: Study 1 participants (N = 13) ingested 1.5 g CrN (CrN-Low), 3 g CrN (CrN-High), 5 g CrM or a placebo in a randomized, crossover study (7d washout) to determine supplement safety (hepatorenal and muscle enzymes, heart rate, blood pressure and side effects) measured at time-0 (unsupplemented), 30-min, and then hourly for 5-h post-ingestion. Study 2 participants (N = 48) received the same CrN treatments vs. 3 g CrM in a randomized, double-blind, 28d trial inclusive of a 7-d interim testing period and loading sequence (4 servings/d). Day-7 and d-28 measured Tendo™ bench press performance, Wingate testing and a 6x6-s bicycle ergometer sprint. Data were analyzed using a GLM and results are reported as mean ± SD or mean change ± 95 % CI. RESULTS: In both studies we observed several significant, yet stochastic changes in blood markers that were not indicative of potential harm or consistent for any treatment group. Equally, all treatment groups reported a similar number of minimal side effects. In Study 2, there was a significant increase in plasma nitrates for both CrN groups by d-7, subsequently abating by d-28. Muscle creatine increased significantly by d-7 in the CrM and CrN-High groups, but then decreased by d-28 for CrN-High. By d-28, there were significant increases in bench press lifting volume (kg) for all groups (PLA, 126.6, 95 % CI 26.3, 226.8; CrM, 194.1, 95 % CI 89.0, 299.2; CrN-Low, 118.3, 95 % CI 26.1, 210.5; CrN-High, 267.2, 95 % CI 175.0, 359.4, kg). Only the CrN-High group was significantly greater than PLA (p < 0.05). Similar findings were observed for bench press peak power (PLA, 59.0, 95 % CI 4.5, 113.4; CrM, 68.6, 95 % CI 11.4, 125.8; CrN-Low, 40.9, 95 % CI -9.2, 91.0; CrN-High, 60.9, 95 % CI 10.8, 111.1, W) and average power. CONCLUSIONS: Creatine nitrate delivered at 3 g was well-tolerated, demonstrated similar performance benefits to 3 g CrM, in addition, within the confines of this study, there were no safety concerns.
Assuntos
Limiar Anaeróbio/efeitos dos fármacos , Suplementos Nutricionais , Força Muscular/efeitos dos fármacos , Nitratos/administração & dosagem , Resistência Física/efeitos dos fármacos , Aptidão Física/fisiologia , Levantamento de Peso/fisiologia , Adulto , Limiar Anaeróbio/fisiologia , Desempenho Atlético , Pressão Sanguínea/efeitos dos fármacos , Creatina , Estudos Cross-Over , Relação Dose-Resposta a Droga , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Força Muscular/fisiologia , Músculo Esquelético/efeitos dos fármacosRESUMO
BACKGROUND: Multi-ingredient pre-workout supplements (MIPS) are popular among resistance trained individuals. Previous research has indicated that acute MIPS ingestion may increase muscular endurance when using a hypertrophy-based protocol but less is known in regard to their effects on strength performance and high intensity running capacity. Therefore, the purpose was to determine if short-term, MIPS ingestion influences strength performance and anaerobic running capacity. METHODS: In a double-blind, randomized, placebo controlled, crossover design; 12 males (19 ± 1 yrs.; 180 ± 12 cm; 89.3 ± 11 kg; 13.6 ± 4.9 %BF) had their body composition assessed followed by 5-repetition maximum (5RM) determination of back squat (BS; 119.3 ± 17.7 kg) and bench press (BP; 92.1 ± 17.8 kg) exercises. On two separate occasions subjects ingested a MIPS or a placebo (P) 30-minutes prior to performing a counter movement vertical jump test, 5 sets of 5 repetitions at 85 % of 5RM of BS and BP, followed by a single set to failure, and an anaerobic capacity sprint test to assess peak and mean power. Subjective markers of energy levels and fatigue were also assessed. Subjects returned one week later for a second testing session using counter treatment. RESULTS: MIPS resulted in a greater number of repetitions performed in the final set to failure in the BP (MIPS, 9.8 ± 1.7 repetitions; P, 9.1 ± 2; p = 0.03, d = 0.38), which led to a greater total volume load (set x repetitions x load) in the MIPS (753 ± 211 kg) compared to P (710 ± 226 kg; p =0.03, d = .20). MIPS ingestion improved subjective markers of fatigue (p = 0.01, d = 3.78) and alertness (p = 0.048, d = 2.72) following a bout of resistance training. An increase in mean power was observed in the MIPS condition (p = 0.03, d = 0.25) during the anaerobic sprint test. CONCLUSION: Results suggest that acute ingestion of a MIPS study may increase upper body muscular endurance. In addition, acute MIPS ingestion improved mean power output during an anaerobic capacity sprint test. However, the practical significance of these performance related outcomes may be minimal due to the small effect sizes observed. MIPS ingestion does appear to positively influence subjective markers of fatigue and alertness during high-intensity exercise.
Assuntos
Limiar Anaeróbio/fisiologia , Suplementos Nutricionais , Músculo Esquelético/fisiologia , Resistência Física/fisiologia , Treinamento Resistido , Limiar Anaeróbio/efeitos dos fármacos , Estudos Cross-Over , Método Duplo-Cego , Alimentos Formulados , Humanos , Masculino , Resistência Física/efeitos dos fármacos , Treinamento Resistido/métodos , Fenômenos Fisiológicos da Nutrição Esportiva , Resultado do Tratamento , Adulto JovemRESUMO
Rapid body mass loss (RBML) before competition was found to decrease hemoglobin mass (Hbmass ) in elite boxers. This study aimed to investigate the underlying mechanisms of this observation. Fourteen well-trained combat athletes who reduced body mass before competitions (weight loss group, WLG) and 14 combat athletes who did not practice RBML (control group, CON) were tested during an ordinary training period (t-1), 1-2 days before an official competition (after 5-7 days RBML in WLG, t-2), and after a post-competition period (t-3). In WLG, body mass (-5.5%, range: 2.9-6.8 kg) and Hbmass (-4.1%) were significantly (P < 0.001) reduced after RBML and were still decreased by 1.6% (P < 0.05) and 2.6% (P < 0.001) at t-3 compared with t-1. After RBML, erythropoietin, reticulocytes, haptoglobin, triiodothyronine (FT3 ), and free androgen index (FAI) were decreased compared with t-1 and t-3. An increase occurred in ferritin and bilirubin. Peak treadmill-running performance and VO2peak did not change significantly, but performance at 4-mmol lactate threshold was higher after RBML (P < 0.05). In CON, no significant changes were found in any parameter. Apparently, the significant decrease in Hbmass after RBML in combat athletes was caused by impaired erythropoiesis and increased hemolysis without significant impact on aerobic performance capacity.
Assuntos
Limiar Anaeróbio/fisiologia , Eritropoese , Hemoglobinas/metabolismo , Hemólise , Esportes/fisiologia , Redução de Peso/fisiologia , Adolescente , Adulto , Androgênios/sangue , Boxe/fisiologia , Eritropoetina/sangue , Exercício Físico/fisiologia , Haptoglobinas/metabolismo , Humanos , Masculino , Artes Marciais/fisiologia , Volume Plasmático , Contagem de Reticulócitos , Tri-Iodotironina/sangue , Luta Romana/fisiologia , Adulto JovemRESUMO
Citrulline has been proposed as an ergogenic aid, leading to an interest in watermelon given its high citrulline concentration. The aim of this study was to determine the effects of a single, pre-exercise dose of l-citrulline, watermelon juice, or a placebo on the total maximum number of repetitions completed over 5 sets, time to exhaustion, maximal oxygen consumption (VO2max), anaerobic threshold, and flow-mediated vasodilation. A randomised double-blind within-participants study design was used to examine these effects among 22 participants (n = 11 males). Supplementation included either a 7.5% sucrose drink containing 6 g of l-citrulline, 710 mL of watermelon juice (~1.0 g citrulline), or a 7.5% sucrose placebo drink. Supplementation was administered 1 or 2 h before exercise testing to investigate a timing effect. There was no significant effect between the three supplements for the total number of repetitions, time to exhaustion, VO2max, anaerobic threshold, or flow-mediated vasodilation. There was also no interaction observed relative to gender or supplement timing (P > 0.05). A single dose of l-citrulline or watermelon juice as a pre-exercise supplement appears to be ineffective in improving exercise performance; however, greater doses of l-citrulline have been shown to be safe and are currently left unexamined.
Assuntos
Citrulina/administração & dosagem , Citrullus , Suplementos Nutricionais , Exercício Físico/fisiologia , Limiar Anaeróbio/fisiologia , Estudos Cross-Over , Método Duplo-Cego , Teste de Esforço , Feminino , Humanos , Masculino , Consumo de Oxigênio , Vasodilatação , Levantamento de Peso/fisiologia , Adulto JovemRESUMO
AIM: The purpose of this study was to investigate the physiologic and performance changes with the addition of high-intensity interval training (HIIT) to a traditional judo programme. METHODS: Nine elite judokas (6 males and 3 females; age: 20±4 yrs; body mass: 69±2 kg; height: 172±7 cm; judo practice time: 13±6 yrs; weekly training volume: 13±5 hours, mean±SD) were recruited to perform a 12-week specific aerobic training program, which consisted of 2 session/week of 30-min continuous run at 60% at Vmax and one session/week of high-intensity interval training 15x1-min at 90% of Vmax with 1 min of active recovery at 60% of Vmax. Before and after the intervention all athletes performed a graded maximal exercise Test to measure maximal oxygen consumption (VÌO2max), ventilatory threshold (VT), maximal velocity (Vmax), heart rate (HR) and VÌO2 off kinetics. VÌO2 and HR recovery kinetics were evaluated on a breath-by-breath basis using a single component exponential function. Anaerobic capacity during specific movements was assessed with the Special judo fitness Test (SJFT). RESULTS: The maximal speed reached during the maximal aerobic power test significantly increaseed (P=0.04), but VÌO2max did not change. τ of HR and of VÌO2 recovery significantly decreased by 17.3% (P=0.04) and 22.0% (P<0.01), respectively. VT increased (6.6%; P=0.03) and the SJFT Index improved (12%; P<0.001) 12% after training. CONCLUSION: The aerobic fitness of elite judokas may be improved by adding aerobic routines to the normal training enhancing the recovery capacity.
Assuntos
Frequência Cardíaca/fisiologia , Treinamento Intervalado de Alta Intensidade/educação , Artes Marciais/fisiologia , Consumo de Oxigênio/fisiologia , Aptidão Física/fisiologia , Adolescente , Limiar Anaeróbio/fisiologia , Teste de Esforço , Feminino , Humanos , Masculino , Artes Marciais/educação , Troca Gasosa Pulmonar/fisiologia , Respiração , Dobras Cutâneas , Adulto JovemRESUMO
OBJECTIVE: To test the hypothesis that hybrid functional electrical stimulation (FES) row training would improve aerobic capacity but that it would remain strongly linked to level of spinal cord lesion because of limited maximal ventilation. DESIGN: Longitudinal before-after trial of 6 months of FES row training. SETTING: Exercise for persons with disabilities program in a hospitaL. PARTICIPANTS: Volunteers (N=14; age range, 21-63y) with complete spinal cord injury (SCI) (T3-11) who are >2 years postinjury. INTERVENTION: Six months of FES row training preceded by a variable period of FES strength training. MAIN OUTCOME MEASURES: Peak aerobic capacity and peak exercise ventilation before and after 6 months of FES row training. RESULTS: FES row training significantly increased peak aerobic capacity and peak minute ventilation (both P<.05). Prior to FES row training, there was a close relation between level of SCI and peak aerobic capacity (adjusted R(2)=.40, P=.009) that was markedly reduced after FES row training (adjusted R(2)=.15, P=.10). In contrast, the relation between level of injury and peak minute ventilation was comparable before and after FES row training (adjusted R(2)=.38 vs .32, both P<.05). CONCLUSIONS: The increased aerobic capacity reflects more than increased ventilation; FES row training effectively circumvents the effect of SCI on peak aerobic capacity by engaging more muscle mass for training, independent of the level of injury.
Assuntos
Terapia por Estimulação Elétrica , Terapia por Exercício , Exercício Físico/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Traumatismos da Medula Espinal/reabilitação , Vértebras Torácicas , Adulto , Limiar Anaeróbio/fisiologia , Terapia Combinada , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente , Condicionamento Físico Humano/métodos , Ventilação Pulmonar , Adulto JovemRESUMO
Introducción: El objetivo de estudio fue la evaluación de la relación entre las potencias aeróbica y anaeróbica, así como la prueba especial de aptitud física para el judo en los judokas masculinos de élite. Método: Diecinueve judokas de élite-edad 24,3 (3,1) años, altura 1,78 (0l,06) m, masa corporal 76,4 (11,2) kg, índice de masa corporal 20,2 (3,6) kgm2 y grasa corpora 11,0 (1,8)-realizaron una prueba de esfuerzo en cinta, la prueba anaeróbica de Wingate para brazos, y la prueba especial de aptitud física para el judo. La prueba de esfuerzo en cinta calculó la captación máxima de oxígeno (VO2max) y la prueba anaeróbica de Wingate evaluó la potencia máxima y media, que describen el rendimiento a corto plazo y la resistencia muscular local, respectivamente. Resultados: El índice de la prueba especial de aptitud física para el judo guardó una relación directa inversa al índice VO2max (r = -0,87, p < 0,01), potencia máxima (r = -0,74, p < 0,01) y potencia media (r = -0,62, p < 0,05). Discusión: Basándonos en estos hallazgos se ha demostrado que la prueba especial de aptitud física para el judo es una prueba de campo que describe principalmente la potencia aeróbica, y en menor grado el rendimiento a corto plazo y la fatiga muscular local. Por tanto, se recomienda su uso a los entrenadores de judo y a los monitores de entrenamiento físico como medida de supervisión de la potencia aeróbica, resaltando la necesidad de una prueba de campo que describa la potencia anaeróbica
Introduction: The purpose of this study was to assess the relationship between aerobic and anaerobic power, and special judo fitness test in elite male judokas. Method: Nineteen elite Judokas [age 24.3 (3.1) yr, height 1.78 (.06) m, body mass 76.4 (11.2) kg, body mass index 20.2 (3.6) kgm-2 and body fat 11.0 (1.8)%] performed a graded exercise test in treadmill, the Wingate anaerobic test for arms and the special judo fitness test. The graded exercise test in treadmill estimated maximal oxygen uptake (VO2max) and the Wingate anaerobic test assessed peak and mean power, descriptors of short-term power output and local muscular endurance respectively. Results: The index of special judo fitness test was in inverse direct relationship with VO2max (r = -0.87, p < 0.01), peak power (r = -0.74, p < 0.01) and mean power (r = -0.62, p < 0.05). Discussion: Based on these findings, it was showed that the special judo fitness test is a field test that describes chiefly aerobic power, and in a lesser degree short-term power output and local muscular fatigue. Therefore, its further use from judo coaches and fitness trainers as a measure to monitor aerobic power is recommended, and the need for a field test that will describe anaerobic power is highlighted
Assuntos
Humanos , Limiar Anaeróbio/fisiologia , Exercício Físico/fisiologia , Artes Marciais/fisiologia , Esportes/fisiologia , Teste de Esforço , Esforço Físico/fisiologia , Desempenho Atlético/fisiologiaRESUMO
The aims of the present study were to investigate the effects of IT on lung function power (P) and oxygen uptake (VO2) at peak performance (peak) and ventilatory anaerobic threshold (VAT) in CF patients who were unable to participate in a standard exercise program (SEP) and to compare these IT responses with corresponding effects in CF patients performing SEP. 20 patients (FEV1 25.5 ± 7.5%; pred; SpO2 < 90% at rest or P lower than 0.3 W/kg) who were unable to participate in SEP were allocated to IT (5 × 20 min weekly). 23 patients (FEV1 31.6 ± 4.2%; p < 0.05) did 5 × 45 min per week of SEP. Lung function remained unchanged in both groups. VO2peak and PVAT increased in both groups (p < 0.05). However, only after the SEP an increase in Ppeak (p < 0.05) and only after IT a higher VO2VAT (p < 0.05) were found. Compared to SEP, IT improved submaximal exercise capacity to a greater extent whereas responsiveness on peak performance was higher in SEP. This seems to indicate a specific potential of IT for positive peripheral muscular adaptations in spite of diminishing potential of pulmonary improvement. IT represents an alternative, effective and safe training regimen with patients with CF and severe lung disease, with a greater potential than SEP.
Assuntos
Fibrose Cística/fisiopatologia , Fibrose Cística/reabilitação , Terapia por Exercício/métodos , Exercício Físico/fisiologia , Índice de Gravidade de Doença , Adolescente , Adulto , Limiar Anaeróbio/fisiologia , Tolerância ao Exercício/fisiologia , Volume Expiratório Forçado , Humanos , Consumo de Oxigênio/fisiologia , Modalidades de Fisioterapia , Resultado do Tratamento , Capacidade Vital , Adulto JovemRESUMO
The synergic effect of regular exercise and resveratrol, a polyphenolic compound with potent antioxidant activity, was investigated against kainate-induced seizures and oxidative stress in mice. After 6 weeks of swimming training, the total body weight decreased and the blood concentration of lactate stabilized statistically in comparison with the sedentary mice, indicate that the training program increased the aerobic resistance of mice. Kainate (30 mg/kg) evoked seizure activity 5 min after injection, and seizure activity was measured seizure rating scores every 5 min up to 2 h. As previously well known experiments, regular exercise and resveratrol (40 mg/kg, daily supplementation for 6 weeks) have an inhibitory effect on kainate-induced seizure activity and oxidative stress. In particularly, a synergistic cooperation of regular exercise and resveratrol was observed in seizure activity, mortality and oxidative stress especially in SOD activity. These results suggest that regular exercise along with an anti-convulsant agent such as resveratrol could be a more efficient method for the prevention of seizure development than exercise alone.
Assuntos
Antioxidantes/farmacologia , Ácido Caínico/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Condicionamento Físico Animal/fisiologia , Convulsões/induzido quimicamente , Convulsões/prevenção & controle , Estilbenos/farmacologia , Limiar Anaeróbio/efeitos dos fármacos , Limiar Anaeróbio/fisiologia , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Catalase/metabolismo , Ácido Láctico/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos ICR , Resveratrol , Convulsões/fisiopatologia , Superóxido Dismutase/metabolismo , Natação/fisiologiaRESUMO
Actualmente, es aceptado por la comunidad científica que el sistema respiratorio puede limitar el ejercicio en personas con enfermedad pulmonar y/o cardiovascular. El objetivo del presente artículo es la revisión de algunos estudios realizados en relación al papel limitante del sistema respiratorio en el rendimiento físico de deportistas. Se realiza una breve descripción técnica de los dispositivos más utilizados para el entrenamiento de la musculatura respiratoria. Finalmente, se presentan los resultados más representativos, obtenidos por diversos investigadores y en distintas poblaciones, relacionados con el entrenamiento de la musculatura respiratoria y sus efectos en el rendimiento físico. Los resultados obtenidos en las distintas investigaciones consultadas sobre el entrenamiento de los músculos respiratorios son dispares, puesto que algunos han mostrado mejoras significativas, mientras otros no han mostrado grandes efectos en el rendimiento. En todos ellos se refleja cómo el sistema respiratorio es un factor limitante del rendimiento físico en deportistas y es preciso plantearse nuevas metodologías, protocolos y planificaciones en el entrenamiento deportivo. El entrenamiento de los músculos respiratorios, tanto mediante dispositivos umbral, de resistencia, o isocapnica, puede provocar mejoras en valores como la presión inspiratoria máxima y mejoras en el rendimiento de algunos deportes; sin embargo, son muy escasos los estudios que han encontrado mejoras en el consumo máximo de oxígeno (VO2max). Las discrepancias entre los estudios analizados pueden estar provocadas por diferencias en las intensidades y duración de los ejercicios utilizados, así como por diferencias en el diseño experimental y el nivel de condición física de los sujetos(AU)
It is currently accepted by the scientific community that the respiratory system may limit the exercise in people with lung disease and / or cardiovascular disease. The aim of this study is to review some studies about the limiting role of the respiratory system in the physical performance of athletes and the breath factors that can limit it. We make a brief technical description of the devices used for respiratory muscle training. Finally, we present the most representative results obtained by different researchers in different populations, related to respiratory muscle training and its effects on physical performance. Results obtained in different studies about respiratory muscles training are uneven as some have shown significant improvements, while others have shown no major effects on the performance. All of them reflect that respiratory system is a limiting factor in the physical performance of athletes and it is necessary to consider new methodologies, protocols and plans in sports training. Respiratory muscles training, either by a threshold device, resistance, or isocapnic, may cause improvements in the values of maximum inspiratory pressure and improvements in some sports performance, however, very few studies have found improvements in peak oxygen consumption. Disagreements between the analyzed studies may be caused due to differences in intensity and duration of the exercises used in the tests, as well as by differences between the experimental design and the physical fitness level of subjects(AU)