Acute and Chronic Effects of Strength Training on Plasma Levels of Adipokines in Man.

Adipose tissue is specialized cells that produce and release adipokines. Exercise may modulate adipokine production in adipocytes. The aim of this longitudinal study was to evaluate the acute and chronic effects of strength training (ST) on plasma levels of adiponectin, leptin, and resistin. Twelve untrained young male participants (23.42±2.67 years) were selected. The training protocol consisted of 3 exercises, with 3 sets of 65% of 1RM (one-repetition maximum) with pause of 90 s between sets with duration of 5 s/repetition (2 s conc/3 s ecc), 3 times a week for 10 weeks. Blood was collected at four time points: before and after the first ST session and before and after the last ST session. The comparisons between adipokine levels before and after the same training session showed acute changes, while the comparisons between levels before or after the first session versus before or after the last session revealed chronic alterations. ST increased adiponectin levels after the first exercise session in comparison to levels before this session [50 952 (46 568-51 894) pg/mL vs. 52 981 (49 901-54 467) pg/mL, p=0.019]. Similar differences were observed for resistin levels, which were higher after the last session compared to before [4 214.4 (±829) pg/mL vs. pre-S30 2 251.3 (±462.2) pg/mL, p=0.0008] and in the comparison between after the last and after the first ST sessions [4 214.4 (±829.0) pg/mL vs. 1 563.7 (±284.8) pg/mL, p=0.004]. Leptin levels acutely changed in the last training session. ST produced acute and chronic changes in plasma adipokines.

Two protocols of aerobic exercise modulate the counter-regulatory axis of the renin-angiotensin system.

AIMS: The renin-angiotensin system (RAS) is a dual system with two opposite arms: i) the classical one formed by the angiotensin converting enzyme (ACE), angiotensin (Ang) II and angiotensin type 1 (AT1) receptors; ii) the counter-regulatory arm consisting of ACE2, Ang-(1-7) and Mas receptor. Physical exercise can modulate this system, however, only animal studies have compared the effects of different intensity protocols on the RAS. No data with humans were provided. Therefore, we investigated the acute effect of two protocols of isowork aerobic exercise [High-Intensity Interval Exercise (HIIE) and Moderate-Intensity Continuous Exercise (MICE)] in plasma and urinary levels of RAS components in physically active men. MAIN METHODS: The HIIE protocol included a 5-minute warm-up cycling at 60-70% of heart rate peak (HRp) intensity followed by 10 sets of 30 s above 90% with 1 min of recovery and 3 min of cool down. The MICE protocol was performed at a constant power corresponding to 60-70% of HRp and finalized at the same total work of HIIE. Blood and urine samples were collected before and after the protocols. Plasma and urinary levels of ACE, ACE2, Ang-(1-7) and Ang II were analyzed by enzyme-linked immunoassay. KEY FINDINGS: While the HIIE protocol significantly increased urinary levels of ACE and plasma levels of ACE2, the MICE protocol elevated urinary concentrations of ACE2 and of Ang-(1-7). A greater increase of urine concentrations of Ang-(1-7) occurred in the MICE if compared with the HIIE protocol. SIGNIFICANCE: Aerobic physical exercise acutely increases the activity of the counter-regulatory RAS axis, mostly the MICE protocol.

Efeitos de carboidratos e eletrólitos sobre a termorregulação e a potência anaeróbia medida após um exercício prolongado no calor / Effects of carbohydrates and electrolytes on thermoregulatory responses and anaerobic performance following a prolonged exercise in the heat

Carboidratos exógenos contribuem para a manutenção da glicose sanguínea e acredita-se que isto possa melhorar o desempenho anaeróbio após um exercício prolongado. Foram objetivos deste estudo comparar a potência máxima e o trabalho total de atletas, no teste anaeróbio de Wingate realizado após 90 min de exercício prolongado (EP), com e sem a ingestão de mistura eletrolítica carboidratada (MEC), bem como as respostas termorregulatórias ocorridas durante o EP. Sete homens (21,4 mais ou menos 4,2 anos; 65,46 mais ou menos 10,45 kg; 9,4 mais ou menos 1,8 de gordura e 60,38 mais ou menos 4,76 mLO2·kg-1·min-1) ingeriram água destilada e cápsulas gelatinosas contendo MEC ou placebo (PLA) a cada 15 min, enquanto realizavam o EP a 60