17th Annual ECSS-Congress, Bruges 2012

Abstract details

Abstract-ID: 1141
Session: [PO-CPP-06] Health & Fitness 2
Lecture room: Gallery
Date & time: 07.07.2016 / -
Authors: Kong, Z., Song, L., Shi, Q., Nie, J.
Institution: University of Macau
Department: Faculty of Education
Country: Macau
Abstract text Background No studies investigates whether low-volume HIE in hypoxia including repeated sprinting exercise (RSE) has an extra effect on body composition and metabolic risk factors. METHODS A single-blind randomized controlled experimental design was used to conduct a 5-week repeated-sprint exercise intervention in hypoxia or normoxia. 24 obese young women completed all 20 sessions either in hypoxic (RSH, N=11) or normoxic high-intensity interval exercise training (RSN, N=13). The RSE protocol comprised 8 s of sprinting and 12 s of rest for a maximum of 60 repetitions for 20 min. Body composition measured by DEXA and blood samples were assessed at pre- and post-intervention in the follicular or luteal phase of menstrual cycle. Physical activity and food diary were estimated during the study. RESULTS There were no within- and between-group differences in daily energy intake and physical activity at pre-, during-, and post-intervention times (p > 0.05). Five weeks of RSE resulted in significantly improvements in absolute and relative V̇O2peak and maximal O2 pulse in both groups (p<0.01). The increments of V̇O2peak and maximal O2 pulse in RSH (∼20%) were twice as much as in RSN (∼10%) (p<0.05, d = 0.88-0.95). There were no significant improvements in weight, BMI, total or regional body composition, TC, HDL-C, LDL-C, and leptin after hypoxic or normoxic training and no differences between groups. There was a trend to decrease in TG in RSH (p=0.051) and the decrement tended to be significant than RSN training, either (RSN -22.8±36.0%, RSH 6.8±31.7%, p = 0.054, d = 0.87). For the subjects in RSH, the changes in V̇O2peak were moderately related to the changes in total FM (r = -0.64, p < 0.05), leg FM (r = -0.74, p < 0.01) and Trunk FM (r = -0.50, p = 0.121), while significant correlations were found between the changes of maximal O2 pulse and the changes of total FM (r = -0.70, p < 0.05), leg FM (r = -0.64, p < 0.05), and Trunk FM (r = -0.64, p < 0.05). In contrast, low and no significant correlations (r = -0.03 to -0.25) between V̇O2peak/maximal O2 pulse and total and regional fat mass in the subjects of RSN. Changes of blood lipids and serum leptin didn’t correlate with the changes of cardiovascular fitness and body composition (p > 0.05). DISCUSSION 20 sessions in five weeks of hypoxic and normoxic repeated-sprint exercise training improved cardiorespiratory fitness but had no effect on body composition, TC, HDL-C, LDL-C and circulating leptin levels in sedentary obese young women, whereas hypoxic RS training had larger enhancements in V̇O2peak, maximal peak O2 pulse and TG than normoxic RS did. We did not observe significant improvements in RSH and RSN group as well as an additive effect on body composition caused by RSH. The changes of V̇O2peak and maximal peak O2 pulse were negatively associated with the changes of total and regional fat mass in RSH but not in RSN, suggesting that hypoxia seems to play a crucial role in improving body composition.
Topic: Health and Fitness
Keyword I: Hypoxia
Keyword II: Repeated sprint exercise training
Keyword III: Obese