ABSTRACT
Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances.
ABSTRACT
O fator de crescimento insulínico-I (IGF-I) e seus componentes exercem importante efeito sobre o crescimento somático e tecidual em muitas espécies. O IGF-I exerce um papel central na hipertrofia muscular associada ao exercício. Este polipeptídeo tem importante função no anabolismo tecidual, causando hipertrofia e hiperplasia tecidual em vários tipos de células, incluindo mioblastos do músculo esquelético e fibroblastos do tendão. As respostas do IGF-I ao exercício físico são dependentes da intensidade e duração do mesmo, podendo sua concentração estar reduzida em exercícios extenuantes (maratona) e aumentado em exercícios de curta duração e intensidade relativa (treinamento com pesos). Sendo assim, esse trabalho tem por objetivo revisar os principais efeitos do IGF-I sobre o músculo esquelético e suas relações com o exercício.
The Insulin growth factor-I (IGF-I) and its components exert important effect on somatic and tissue growth in many species. The IGF-I exerts a central role in muscle hypertrophy associated to exercise. It has an important function in tissue anabolism, causing tissue hypertrophy and hyperplasia in many cell types, including skeletal muscle myoblasts and tendon fibroblasts. IGF-I responses to physical exercise are dependant on its intensity and duration, so that, its levels may be reduced in exhausting exercises marathon) and enhanced in short duration and relative intensity exercises (weight training). This issue has the objective to review the main effects of IGF-I on skeletal muscle and the relationship with exercise.
