Energetic responses of head-out water immersion at different temperatures during post-exercise recovery and its consequence on anaerobic mechanical power.

PURPOSE: While exercise recovery may be beneficial from a physiological point of view, it may be detrimental to subsequent anaerobic performance. To investigate the energetic responses of water immersion at different temperatures during post-exercise recovery and its consequences on subsequent anaerobic performance, a randomized and controlled crossover experimental design was performed with 21 trained cyclists. METHOD: Participants were assigned to receive three passive recovery strategies during 10 min after a Wingate Anaerobic Test (WAnT): control (CON: non-immersed condition), cold water immersion (CWI: 20 â„ƒ), and hot water immersion (HWI: 40 â„ƒ). Blood lactate, cardiorespiratory, and mechanical outcomes were measured during the WAnT and its recovery. Time constant (τ), asymptotic value, and area under the curve (AUC) were quantified for each physiologic parameter during recovery. After that, a second WAnT test and 10-min recovery were realized in the same session. RESULTS: Regardless the water immersion temperature, water immersion increased [Formula: see text] (+ 18%), asymptote ([Formula: see text]+ 16%, [Formula: see text] + 13%, [Formula: see text] + 17%, HR + 16%) and AUC ([Formula: see text]+ 27%, [Formula: see text] + 18%, [Formula: see text] + 20%, HR + 25%), while decreased [Formula: see text] (- 33%). There was no influence of water immersion on blood lactate parameters. HWI improved the mean power output during the second WAnT (2.2%), while the CWI decreased 2.4% (P < 0.01). CONCLUSION: Independent of temperature, water immersion enhanced aerobic energy recovery without modifying blood lactate recovery. However, subsequent anaerobic performance was increased only during HWI and decreased during CWI. Despite higher than in other studies, 20 °C effectively triggered physiological and performance responses. Water immersion-induced physiological changes did not predict subsequent anaerobic performance.

Consumo de oxigênio de recuperação em resposta a duas sessões de treinamento de força com diferentes intensidades / Recovery oxygen uptake in response to two resistance training sessions at different intensities

O objetivo do presente estudo foi comparar o comportamento do consumo de oxigênio (VO2) em resposta a uma sessão de treinamento de força (TF) com objetivo em hipertrofia muscular (HP) com uma sessão com objetivo em resistência muscular localizada (RML). Nove indivíduos do sexo masculino (23,1 ± 2,1 anos) foram recrutados para este estudo. A força muscular dinâmica foi mensurada através do teste de 1RM. O VO2 foi coletado durante o repouso e 10 minutos de recuperação com um analisador de gases (CPX/D). As sessões foram compostas por um exercício de membros superiores (supino) e um de membros inferiores (agachamento), e compreenderam a execução de três séries de 6-8 repetições máximas (RM) a 80 por cento de 1RM para HP e 15-20 RM a 55 por cento de 1RM para RML. Foram analisados os dados de VO2 pós-exercício (EPOC), gasto energético (GE) de recuperação e constante de tempo de VO2 (CT). Foi observado que ambas sessões provocaram comportamento significativamente elevado de VO2 durante os 10min de recuperação em relação aos valores de repouso. Não houve diferenças significativas entre os valores de EPOC (litros) para HP (2,21 ± 0,54) e RML (2,60 ± 0,44), GE (kcal) para HP (10,36 ± 2,53) e RML (12,18 ± 2,04) e CT (segundos) para HP (56 ± 7) e RML (57 ± 6) (p > 0,05). Esses resultados demonstraram que uma sessão de TF com objetivo em RML é capaz de causar distúrbios metabólicos semelhantes àqueles provocados por uma sessão de HP, mesmo que seja em menor intensidade relativa a carga máxima.

The purpose of the present study was to compare the oxygen uptake ( VO2) behavior in response to a resistance exercise (RE) session with aim of hypertrophy (HP) with another session with aim of local muscular endurance (LME). Nine young men (23.1± 2.1 years) voluntarily participated in the present study. Dynamic muscle strength was measured with one repetition maximum test (1RM). O VO2 was collected at rest and ten minutes after exercise with a gas analyzer (CPX/D). The RE protocols were composed of one upper body exercise (bench press) and one lower body exercise (squat) with the execution of 3 sets of 6-8 maximum repetitions (RM) with 80 percent of 1RM in HP session and 3 sets of 15-20 RM with 55 percent of 1 RM in LME session. Exercise post oxygen consumption (EPOC), energy cost (EC) and time constant (TC) of VO2 were analyzed. The results showed that both RE sessions provoked significant elevated VO2 after RE in comparison to rest values. There were no differences between groups in the EPOC (l) (HP: 2.21 ± 0.54 vs. LME: 2.60 ± 0.44), EC (Kcal) (HP: 10.36 ± 2.53 vs LME: 12.18 ± 2.04) and TC of VO2 (s) (HP: 56 ± 7 vs. LME: 57 ± 6) (p>0.05). These results demonstrated that a RE session with the aim of LME gain is capable of causing similar metabolic impact to the RE session with HP aim, even if it is performed at lower intensity concerning maximal load.

Neuromuscular economy, strength, and endurance in healthy elderly men.

Declines in muscular strength resulting from reduced neural activity may influence the reduction in aerobic capacity in older men. However, there has been little investigation into the relationship between muscular strength and economy of movement during aerobic exercise in elderly subjects. Thus, the purpose of this study was to investigate the possible relationship between strength, aerobic performance, and neuromuscular economy in older men. Twenty-eight aged men (65 ± 4 years old) were evaluated in dynamic (1 repetition maximum test), isometric strength (maximal voluntary contraction), and rate of force development. Peak oxygen uptake, maximal workload, and ventilatory threshold were determined during a ramp protocol on a cycle ergometer. Throughout the same protocol, the neuromuscular economy (electromyographic signal) of the vastus lateralis was measured. Significant correlations were found between muscular strength, cardiorespiratory fitness, and neuromuscular economy (r = 0.43-0.64, p < 0.05). Our results suggest that cardiorespiratory capacity and economy of movement are associated with muscular strength during aging.

Analysis of muscle activation during different leg press exercises at submaximum effort levels.

Many studies have analyzed muscle activity during different strength exercises. Although the leg press (LP) is one of the most common exercises performed, there is little evidence of lower limb muscle activity patterns during this exercise and its variations. Thus, this study aimed to verify how mechanical changes and loads affect lower limb muscle activity during the performance of different LP exercises. Fourteen women performed 3 LP exercises: 45 degrees LP (LP45), LP high (LPH), and LP low (LPL) at 40% and 80% of the 1 repetition maximum. The electromyographic activity of the rectus femoris, vastus lateralis, biceps femoris, gastrocnemius, and gluteus maximus was recorded. Results suggested that mechanical changes affect lower limb muscle activity and that it is related to the load used. At moderate effort levels, the rectus femoris and gastrocnemius were more active during the LP45 and LPL than during the LPH. At a high effort level, the rectus femoris and vastus lateralis (quadriceps) were more active during the LPL than the LPH. Again, the rectus femoris and gastrocnemius were more active during the LP45 and LPL than the LPH. On the other hand, gluteus maximus activity was greater during the LPH than the LPL. This study found that coordination patterns of muscle activity are different when performing LP variations at high or moderate effort levels because of mechanical changes and different loads lifted during the different LP exercises. These results suggest that if the goal is to induce greater rectus femoris and vastus lateralis (quadriceps) activation, the LPL should be performed. On the other hand, if the goal is to induce gluteus maximus activity, the LPH should be performed.