The effect of high intensity interval training with genistein supplementation on mitochondrial function in the heart tissue of elderly rats.

INTRODUCTION: For the most part, heart disease increases with age; on the other hand, although the role of exercise and antioxidants in the health of the elderly has been reported, the simultaneous effect of these two interventions is a new research topic. Thus, the aim of this study was to evaluate the effect of eight weeks of high intensity interval training (HIIT) and genistein (G) supplementation on oxidative stress, apoptosis and mitochondrial biogenesis in the heart tissue of elderly rats. METHODS: In this experimental study, 40 elderly female Sprague-Dawley rats aged 20 ± 2 months and weighing 250 ± 30 g were randomly divided into five groups of eight animals, including: (1) control (C), (2) sham (Sh), (3) HIIT, (4) HIIT + G and (5) G. Also, to evaluate the effect of time passage on the variables, 8 healthy young rats were included in the healthy young control group. HIIT protocol was performed for eight weeks, three sessions with an intensity of 95-90 % VO2max at high intensity intervals and 45-45 % VO2max at low intensity intervals. Ge was received daily at a dose of 60 mg/kg peritoneally. Data analysis was performed using one-way ANOVA with Tukey's post hoc test (P ≤ 0.05). RESULTS: In the HIIT and HIIT + G groups, levels of Bax, Bax/Bcl-2 ratio, MDA, PAB, GSSG were lower and levels of PGC-1α, TFAM, GSH, GSH/GSSG ratio and NDUFS7 were higher than the control and sham groups (P ≤ 0.05). In the HIIT + G group, levels of Bcl-2 were significantly higher than the control group (P ≤ 0.05). In the HIIT + G group, levels of Bax, GSSG, Bax/Bcl-2 ratio, and PAB were lower, and levels of GSH/GSSG ratio, Bcl-2, PGC-1α, TFAM and NDUFS7 were higher than the G consumption group (P ≤ 0.05). In the HIIT + G group, levels of PGC-1α and TFAM were significantly higher and levels of MDA and PAB were lower than the HIIT group (P ≤ 0.05). CONCLUSION: Both HIIT and G consumption seem to have beneficial effects on reducing oxidative stress; in addition, the interaction of these two variables on the improvement of apoptosis and mitochondrial biogenesis is more favorable than the effect of either one alone. However, more studies are needed on different pathways of apoptosis following G administration.

Short-term circuit resistance training improves insulin resistance probably via increasing circulating Adropin.

Aim and background: The underlying mechanism of exercise-induced insulin resistance (IR) improvement is unclear. Adropin is a multifunctional peptide has a significant role in the regulation of physical activity and insulin sensitivity. Thus, the aim of this study was to evaluate the effects of various circuit resistance (CRT) intensities on circulating adropin levels and IR and their relation. Method: Forty-five voluntarily male men randomly were divided into 5 groups; control and 4 groups of CRT (20%, 40%, 60% and 80% of one-repetition maximum (1-RM)). Training groups performed CRT protocol 3 times a week for 6 weeks. Blood samples were drawn before and 48 h after the last training session and used for analyzing serum levels of adropin, glucose and insulin. Results: The results showed that varying CRT intensities were associated with adropin elevation in comparison to the control group. Further analysis revealed that plasma adropin is higher in the 20% 1-RM group compared to the 40% 1-RM group. Furthermore, fasting insulin and glucose, as well as IR, were decreased in response to different CRT intensities. In addition, these reductions were significantly correlated with adropin level. Conclusion: It can be speculated that different CRT intensities improve IR probably via increasing adropin level, and should be considered as an effective training method for diminishing glucose metabolism disorders.

Pilates and TRX training methods can improve insulin resistance in overweight women by increasing an exercise-hormone, Irisin.

AIMS AND BACKGROUND: Physical inactivity is leading to obesity and consequently insulin resistance and diabetes. Feasible and cost efficient strategies like Pilates and total body resistance exercise (TRX) training can impede obesity and its compilation. The aim of this study was to investigate the effects of 8 weeks Pilates and TRX training programs on irisin concentration and insulin resistance in overweight women. METHOD: Thirty overweight women (Body mass index (BMI): 25-29.9 kg/m2) were divided, based on their BMI, into 3 groups; control, Pilates and TRX. The participants in the training groups were subjected to moderate intensity of Pilates or TRX exercise training 3 times a week for 8 weeks. Blood samples were taken at pre-test and 48 h after the last training session and used for analyzing irisin, insulin and glucose. Data were analyzed by ANCOVA and paired-samples t-test. RESULTS: The finding showed that the Pilates training decreased body weight and BMI compared to the pre-test (P < 0.05). Also, it has been revealed that irisin concentration in response to Pilates and TRX training programs were increased in comparison with the control group (P < 0.05). However, there was no significant difference in irisin concentrations between training groups (p > 0.05). Moreover, fasting insulin, glucose and insulin resistance were significantly reduced after exercise intervention compared to the pre-test which were significantly lowered compared to the control group as well. CONCLUSION: The results suggest Pilates and TRX trainings are two efficient model of exercise that by eliciting an exercise-hormone, irisin, can improve insulin resistance in overweight women.