Postprandial lipoprotein profile in two modes of high-intensity intermittent exercise

Two Weekly Sessions of High-Intensity Interval Training Improve Metabolic Syndrome and Hypertriglyceridemic Waist Phenotype in Older Adults: A Randomized Controlled Trial

Background: Exercise training provides physiological benefits for maintaining good health. A common exercise strategy is high-intensity interval training (HIIT). HIIT may alleviate metabolic syndrome (MetS) and hypertriglyceridemic waist (HTGW) phenotype, but remains largely unstudied in ageing participants. The aim of this research was to investigate the impact of 2 weekly HIIT sessions on MetS markers and HTGW-related factors in older adults. Methods: In this randomized controlled trial, 140 older men and women were randomized into two groups, the experimental group (EG), and the control group (CG). The EG performed 2 weekly sessions of HIIT during 12 weeks. HIIT sessions consisted of 40 min treadmill running/walking: a 10 min warm-up at 50%-60% of maximum heart rate (HR_max), followed by 10 sets of 1 min bouts at 85%-90% of HR_max interspersed with 1 min walking at self-selected pace (totaling 20 min), and 10 min cool-down walking at self-selected pace. The CG did not perform any type of intense exercise during the intervention period. Results: Participants in the EG of both sexes decreased MetS, HTGW, blood pressure, cholesterol, and glycemia (P < 0.05). After training, the number of hypertensive men decreased by 100% and women by 70%. There was a 75% reduction in women with diabetes, a 100% reduction in MetS indicators and over 80% reduction in HTGW in participants of both sexes. Conclusion: Two weekly sessions of HIIT proved to be feasible and effective to induce clinically relevant improvements in MetS and HTGW indicators.

Impact of 5-week high-intensity interval training on indices of cardio metabolic health in men

PURPOSE

To compare the acute and chronic effects of high-intensity intermittent training (HIIT) and moderate-intensity continuous training (MICT) on indices of cardio-metabolic health: (HDL-c, total cholesterol, triglycerides, heart ratio, and phase angle/PhA) in physically active men.

METHODS

Twenty active men were randomly allocated to HIIT (n = 10), or MICT (n = 10) for 5 weeks, three times per week. HIIT consisted of running 5 km with 1-min at 100% of maximal aerobic speed interspersed by 1-min passive recovery while subjects in MICT group ran continuously the same 5 km at 70% of maximal aerobic speed. Blood samples were collected at different moments during the first and last exercise session. Before and after 5 weeks of both exercise training protocols, heart ratio (during exercise session) and PhA were measured pre and post-exercise training.

RESULTS

Fasting HDL-c levels did not change after 5 weeks of HIIT or MICT. Perceptual variation of HDL pre and post training (fed state) tended to differ between HIIT and MICT (p = 0.09). All lipoproteins parameters (HDL-c, total cholesterol, triglycerides and non-HDL) were increased in post-acute exercise session compared to pre-exercise during the first and last training session, these being observed after both training protocols. PhA and heart rate measured at different times during the first and last training session were not affected in both training protocols.

CONCLUSION

These results indicate that HIIT and MICT modify the post-exercise lipoprotein profile acutely. On the other hand, only HIIT tended to increase HDL-c levels chronically.

Reverse Cholesterol Transport: Molecular Mechanisms and the Non-medical Approach to Enhance HDL Cholesterol

Dyslipidemia (high concentrations of LDL-c and low concentrations of HDL-c) is a major cause of cardiovascular events, which are the leading cause of death in the world. On the other hand, nutrition and regular exercise can be an interesting strategy to modulate lipid profile, acting as prevention or treatment, inhibiting the risk of diseases due to its anti-inflammatory and anti-atherogenic characteristics. Additionally, the possibility of controlling different training variables, such as type, intensity and recovery interval, can be used to maximize the benefits of exercise in promoting cardiovascular health. However, the mechanisms by which exercise and nutrients act in the regulation of cholesterol and its fractions, such as reverse cholesterol transport, receptors and transcription factors involved, such as PPARs and their role related to exercise, deserve further discussion. Therefore, the objective of this review is to debate about non-medical approaches to increase HDL-c, such as nutritional and training strategies, and to discuss the central mechanisms involved in the modulation of lipid profile during exercise, as well as that can be controlled by physical trainers or sports specialists in attempt to maximize the benefits promoted by exercise. The search for papers was performed in the databases: Medline (Pubmed), Science Direct, Scopus, Sport Discus, Web of Science, Scielo and Lilacs until February 2016.