Shorter recovery time following high-intensity interval training induced higher body fat loss among overweight women

Background: High intensity interval training (HIIT) has been widely employed as an exercise protocol to reduce fat, and also in addition, interval recovery periods are the most important factors which can have great impact on weight loss. Therefore, the aim of this study was the evaluation of different recovery time between HIIT program on metabolic responses and weight loss in overweight women. Methods: Twenty-four overweight (BMI 29.5±3.5 kg/m2) volunteer women were randomly assigned into three groups (n=8/group) to study the effects of different recovery times: (group 1; HIIT with 60/60 activity-rest ratio (sec), group 2; HIIT with 60/30 activity-rest ratio (sec), and group 3 was set as a control. The participants performed 3 times per week 4 bouts/session (80% of Heart Rate Reserve). The exercise program gradually increased to 10 bouts/session. Results: The most important findings of this study were a change in the Body fat percentage (BF %) in the between group comparison: group1 (40.5±0.9), group 2 (41.2±0.7) and group 3 (41.1±1.1). Compared to the control group the 60/30 sec HIIT resulted in a significant decrease in BF % (p=0.002). However, no other significant differences in the body composition were found. Either there were no significant differences between the groups in T4, T3 and TSH, cortisol, HGH, FBS, blood insulin, insulin resistance insulin sensitivity or fatnessassociated hormones. Conclusions: In conclusion, considerable decrease in BF % in the 60/30 sec. rest interval group indicates that 30 sec recovery period in HIIT may reduce fat % more efficiently than 60 sec.peerReviewe

The effect of endurance training combined with adenosine on the gene expression of UCP-1 and MAPK p38 in subcutaneous adipose tissue of male Wistar rats fed a high -fat diet

Background: Strategies to increase energy expenditure are an attractive approach to reduce excess fat storage and body weight to improve metabolic health. The aim of the present study was to investigate the effects of endurance training combined with adenosine injection on the gene expression of UCP-1 and MAPK p38 in the subcutaneous adipose tissue of male rats fed a high-fat diet. Materials and Methods: Forty rats were randomly divided into 4 groups: 1. normal control, 2. high-fat diet (HFD) control, 3. HFD + adenosine, and 4. HFD + endurance training + adenosine. After 13 weeks of HFD, 12 weeks of endurance training on a moderate-intensity treadmill was performed. UCP-1 and MAPK p38 mRNA levels were measured by RT-PCR. Results: A significant increase in UCP-1 was observed with in HFD + endurance training + adenosine and HFD + adenosine compared to normal and HFD controls. A significant decrease in MAPK p38 was also observed with HFD + endurance training + adenosine and HFD + adenosine compared to HFD. Conclusion: Endurance training and adenosine are likely activators of UCP-1 gene expression and can be used as effective lipolytic agents in obesity. The MAPK p38 pathway increases glucose uptake by insulin and also induces oxidative phosphorylation in mitochondria following a healthy diet and aerobic activity