The Combined Effects of High-Intensity Interval Exercise Training and Dietary Supplementation on Reduction of Body Fat in Adults with Overweight and Obesity: A Systematic Review.

Excessive body fat is associated with various comorbidities including cardiovascular disease, type 2 diabetes mellitus and certain types of cancer. The search for effective, relatively easy to maintain body-fat reduction interventions has been ongoing. We aimed to review the current literature to assess the effectiveness of high-intensity interval training with and without dietary supplementation on body fat loss, concentration of markers of metabolic health and aerobic capacity of adults with overweight and obesity. Seventy full-text articles were assessed to determine their eligibility and thirteen were included in the review. The methodology of this systematic review was developed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Almost all studies (93%) demonstrated effectiveness of high-intensity interval training of various protocols in reducing body fat, improving metabolic health and aerobic capacity of adults with overweight and obesity. These effects were enhanced by an addition of a dietary supplement, such as green tea or ginger or other. Although combining HIIT with dietary supplementation seem to improve body composition, metabolic health and aerobic capacity in adults with overweight and obesity in some instances to a greater extent than HIIT alone, it does not seem to be necessary to combine these two interventions.

The Effects of Omega-3 Fatty Acid Supplementation on the Lipid Profile and Cardiovascular Markers Following Downhill Running in Long-Distance Runners.

Exercise-induced injury may intensify inflammatory response and reduce the cardiovascular protection mechanisms of omega 3 polyunsaturated fatty acids (ω 3 PUFA). Therefore, this study aimed to determine the erythrocyte content of fatty acids (ω 3 and ω 6), the levels of cardiac damage markers (CKMB, hsTnT, H - FABP), the concentration of inflammation mediators (IL-6, TNF α) in long distance runners supplemented with ω 3 PUFA. Twenty-four male long distance runners, who were randomly assigned to a placebo group (GrP) or a group supplemented (GrSuppl) with a daily dose of 3,000 mg of ω 3 PUFA for three weeks, participated in the study. Participants performed a downhill running exercise test. Blood samples were collected at rest and after the exercise protocol to analyse the levels of cardiac markers and inflammatory cytokines. The erythrocyte membrane content of EPA and DHA in the GrSuppl at the 3rd week of supplementation was significantly higher than at the baseline (p < 0.001). The erythrocyte membrane content of ω 3 PUFA in the GrSuppl was significantly higher at the completion of supplementation (p < 0.001). Supplementation with ω 3 PUFA improved blood lipid profiles and reduced the concentration of inflammation mediators measured after the eccentric exercise tests. The increased ω 3 PUFA content in the erythrocyte membrane and lower blood concentrations of cardiac damage markers and inflammation mediators in distance runners supplemented for three weeks with ω 3 PUFA suggest that the cardiovascular function has been improved.

The Effect of High-Intensity Interval Exercise on Short-Term Glycaemic Control, Serum Level of Key Mediator in Hypoxia and Pro-Inflammatory Cytokines in Patients with Type 1 Diabetes-An Exploratory Case Study.

Type 1 diabetes (T1D) is associated with hyperglycaemia-induced hypoxia and inflammation. This study assessed the effects of a single bout of high-intensity interval exercise (HIIE) on glycaemia (BG) and serum level of pro-inflammatory cytokines, and an essential mediator of adaptive response to hypoxia in T1D patients. The macronutrient intake was also evaluated. Nine patients suffering from T1D for about 12 years and nine healthy individuals (CG) were enrolled and completed one session of HIIE at the intensity of 120% lactate threshold with a duration of 4 × 5 min intermittent with 5 min rests after each bout of exercise. Capillary and venous blood were withdrawn at rest, immediately after and at 24 h post-HIIE for analysis of BG, hypoxia-inducible factor alpha (HIF-1α), tumour necrosis factor alpha (TNF-α) and vascular-endothelial growth factor (VEGF). Pre-exercise BG was significantly higher in the T1D patients compared to the CG (p = 0.043). HIIE led to a significant decline in T1D patients' BG (p = 0.027) and a tendency for a lower BG at 24 h post-HIIE vs. pre-HIIE. HIF-1α was significantly elevated in the T1D patients compared to CG and there was a trend for HIF-1α to decline, and for VEGF and TNF-α to increase in response to HIIE in the T1D group. Both groups consumed more and less than the recommended amounts of protein and fat, respectively. In the T1D group, a tendency for a higher digestible carbohydrate intake and more frequent hyperglycaemic episodes on the day after HIIE were observed. HIIE was effective in reducing T1D patients' glycaemia and improving short-term glycaemic control. HIIE has the potential to improve adaptive response to hypoxia by elevating the serum level of VEGF. Patients' diet and level of physical activity should be screened on a regular basis, and they should be educated on the glycaemic effects of digestible carbohydrates.