Background and Objective

This study examined the infl uence of short-term normobaric hypoxic training on metabolic syndrome-related markers in overweight and normal-weight men.

Material and Methods

Forty-one Japanese men were included and divided into two groups based on their body mass indices (BMIs): BMI≥25 or BMI<25. Participants in the overweight and normal-weight groups were randomly classifi ed into the hypoxic exercise group (hypoxic overweight, HO; hypoxic normal-weight, HN) and the normoxic exercise group (normoxic overweight, NO; normoxic normal-weight, NN). Subjects performed treadmill exercise three days per week for four weeks at an exercise intensity of 60% of maximum heart rate, under either normobaric hypoxic or normobaric normoxic conditions, for 50 min (including 5 minute warm-up and cool-down periods) after a 30-min rest period. The study parameters included weight, body fat percentage, BMI, heart rate, waist circumference, ankle-brachial pulse wave velocity (PWV), blood sugar, triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), fasting insulin, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) scores, and adiponectin levels. Repeated measures two-way analysis of variance was used to examine diff erences in the mean parameter values between the two groups (overweight and normal-weight) before and after training.

Results

Hypoxic training improved the weight, body fat percentage, BMI, waist circumference, PWV, TC, LDL-C levels, and HOMA-IR scores in the overweight and normal-weight groups (p<0.05). In addition, TG level, HDL-C level, and HOMA-IR scores showed signifi cant interactions with hypoxic training, as these parameters improved in the hypoxic overweight group (p<0.05).

Conclusion

These results suggest that hypoxic training could be useful for improving arterial stiff ness, circulatory system function, body composition, and energy metabolism in adult males.