Six Sessions of Low-volume High-intensity Interval Exercise Improves Resting Fat Oxidation.

It remains unclear whether a practical model of low-volume high-intensity interval exercise improves resting fat oxidation (FatOx) that is associated with metabolic health. We aimed to determine the effects of a short-term practical model of high-intensity interval training (HIIT) on resting FatOx in young, healthy males. Thirty healthy males were randomly assigned to either single (HIITsingle; n=13) or double HIIT (HIITdouble; n=17) group. The HIITsingle group trained once a day, 3 days/week for 2 weeks, whilst the HIITdouble group performed 6 sessions of high-intensity exercise over 5 days by exercising twice a day every second day. Both groups completed 6 high-intensity exercise sessions consisting of 10×60 s of cycling at peak power output, interspersed by 75 s cycling at 60 W. With 1% false discovery rate (FDR) significance threshold, resting respiratory exchange ratio similarly decreased in HIITsingle (pre=0.83±0.03 vs post=0.80±0.03) and HIITdouble group (pre=0.82±0.04 vs post=0.80±0.02) [(p=0.001; partial eta squared (η)=0.310, FDR-adjusted p value=0.005)]. Resting FatOx increased similarly in HIITsingle (pre=1.07±0.39 mg·kg-1 fat free mass (FFM)·min-1 vs post=1.44±0.36 mg·kg-1 FFM·min-1) and HIITdouble group (pre=1.35±0.45 mg·kg-1 FFM·min-1 vs post=1.52±0.29 mg·kg-1 FFM·min-1) [(p<0.001; η=0.411, FDR-adjusted p value=0.005)]. Our results demonstrate that only six sessions of a practical model of low-volume high-intensity exercise improves resting FatOx in young, healthy males.

Evidence-Based Effects of High-Intensity Interval Training on Exercise Capacity and Health: A Review with Historical Perspective.

Engaging in regular exercise results in a range of physiological adaptations offering benefits for exercise capacity and health, independent of age, gender or the presence of chronic diseases. Accumulating evidence shows that lack of time is a major impediment to exercise, causing physical inactivity worldwide. This issue has resulted in momentum for interval training models known to elicit higher enjoyment and induce adaptations similar to or greater than moderate-intensity continuous training, despite a lower total exercise volume. Although there is no universal definition, high-intensity interval exercise is characterized by repeated short bursts of intense activity, performed with a "near maximal" or "all-out" effort corresponding to ≥90% of maximal oxygen uptake or >75% of maximal power, with periods of rest or low-intensity exercise. Research has indicated that high-intensity interval training induces numerous physiological adaptations that improve exercise capacity (maximal oxygen uptake, aerobic endurance, anaerobic capacity etc.) and metabolic health in both clinical and healthy (athletes, active and inactive individuals without any apparent disease or disorder) populations. In this paper, a brief history of high-intensity interval training is presented, based on the novel findings of some selected studies on exercise capacity and health, starting from the early 1920s to date. Further, an overview of the mechanisms underlying the physiological adaptations in response to high-intensity interval training is provided.

The Role of Exercise, Diet, and Cytokines in Preventing Obesity and Improving Adipose Tissue.

The prevalence of obesity continues to rise worldwide despite evidence-based public health recommendations. The promise to adopt a healthy lifestyle is increasingly important for tackling this global epidemic. Calorie restriction or regular exercise or a combination of the two is accepted as an effective strategy in preventing or treating obesity. Furthermore, the benefits conferred by regular exercise to overcome obesity are attributed not only to reduced adiposity or reduced levels of circulating lipids but also to the proteins, peptides, enzymes, and metabolites that are released from contracting skeletal muscle or other organs. The secretion of these molecules called cytokines in response to exercise induces browning of white adipose tissue by increasing the expression of brown adipocyte-specific genes within the white adipose tissue, suggesting that exercise-induced cytokines may play a significant role in preventing obesity. In this review, we present research-based evidence supporting the effects of exercise and various diet interventions on preventing obesity and adipose tissue health. We also discuss the interplay between adipose tissue and the cytokines secreted from skeletal muscle and other organs that are known to affect adipose tissue and metabolism.

Nutritional Considerations for Injury Prevention and Recovery in Combat Sports.

Sports participation is not without risk, and most athletes incur at least one injury throughout their careers. Combat sports are popular all around the world, and about one-third of their injuries result in more than 7 days of absence from competition or training. The most frequently injured body regions are the head and neck, followed by the upper and lower limbs, while the most common tissue types injured are superficial tissues and skin, followed by ligaments and joint capsules. Nutrition has significant implications for injury prevention and enhancement of the recovery process due to its effect on the overall physical and psychological well-being of the athlete and improving tissue healing. In particular, amino acid and protein intake, antioxidants, creatine, and omega-3 are given special attention due to their therapeutic roles in preventing muscle loss and anabolic resistance as well as promoting injury healing. The purpose of this review is to present the roles of various nutritional strategies in reducing the risk of injury and improving the treatment and rehabilitation process in combat sports. In this respect, nutritional considerations for muscle, joint, and bone injuries as well as sports-related concussions are presented. The injury risk associated with rapid weight loss is also discussed. Finally, preoperative nutrition and nutritional considerations for returning to a sport after rehabilitation are addressed.