تأثیر تمرینات مقاومتی و مصرف مکمل عصارۀ شکلات تلخ بر میزان مقادیر عامل میوژنیک 5 پلاسمایی و قدرت عضلانی سالمندان

Background and Aim: Catechins in dark chocolate can improve the reduction of muscle mass in the elderly due to the sarcopenia by the positive effect on muscle growth. The purpose of this study was to investigate the effect of eight weeks resistance training and dark chocolate extract supplementation on the plasma levels of Myogenic Factor 5 (Myf5) and muscle strength in the older adults. Materials and Methods: In this quasi-experimental study, 36 elderly adults (19 males, 17 females), were objectively selected and randomly divided into four groups: training (RT) (n=8), supplement (S) (n=10), training + supplement (RT+S)(n=9), and control (C)(n=9). Subjects of RT and RT+S groups underwent a resistance training program. S and RT+S groups consumed capsules containing 500mg of dark chocolate extract –containing epicatechin- every day. Before and after eight weeks intervention, the plasma levels of Myf5 were measured by ELIZA method and the muscle strength was measured by 1-Repeatation Maximum (1RM) test. The data were analyzed with ANOVA and LSD post hoc tests. Results: Myf5 values increased significantly in RT, S and RT+S groups compared to C group after the intervention (P≤0.05). Myf5 values were significantly higher in RT+S group compared to RT and S groups (P≤0.05). Moreover, chest press and leg press maximal strength increased in RT and RT+S groups in comparison with C group (P≤0.05). Conclusion:  8-weeks resistance training with the consumption of dark chocolate extract supplement have more efficient effects on the enhancement of plasma myf5 in the older adults compared to mere resistance training.