Author(s): TEE, C.C.L., CHONG, M.C.2, COOKE, M.B.3, RAHMAT, N.1, YEO, W.K.1, CAMERA, D.M.2 , Institution: 1 NATIONAL SPORTS INSTITUTE OF MALAYSIA; 2 SWINBURNE UNIVERSITY OF TECHNOLOGY, Country: MALAYSIA, Abstract-ID: 315

INTRODUCTION:
Combining exercise and hypoxia may have synergistic effects to mediate multiple health responses in adults with overweight. The purpose of this study was to investigate the acute effect of moderate hypoxia (MH) combined with three different modes of exercise (e.g., aerobic, sprint-interval, or functional exercise) on blood glucose regulation and expressions of selected circulating microRNAs.
METHODS:
Thirteen men (31±4 years, 80.1±6.3 kg, 26.3±3.2% fat) performed three acute exercises (60 min low-intensity cycling exercise, 20 x 4 s at 7.5% sprint interval cycling, and bodyweight functional exercises: 4 x 20-s half-squat, gluteal contractions, calf-raises and knee raises) under moderate normobaric hypoxia (MH; FiO2 = 16.5%). Plasma levels of glucose, insulin iAUC, and circulating microRNAs expression (c-miRs-486-5p, -126-5p, and -21-5p). Heart rate, oxygen saturation, physical activity enjoyment scale, and perceptual measures were recorded during exercise.
RESULTS:
Following an acute sprint interval (p=0.028) and low-intensity cycling (p=0.006) under MH, plasma glucose, and insulin concentration were lower vs control. No differences were observed in functional exercise vs control, low-intensity vs sprint interval cycling, low-intensity cycling vs functional exercises and sprint interval cycling vs functional exercises. Heart rate was greater in sprint interval cycling (p<0.001) vs other exercise modalities while oxygen saturation and physical activity enjoyment scale were not different between exercise modalities. No differences were observed in the expression of circulating miRNAs (c-miR-486-5p, -126-5p, or -21-5p) (p>0.05).
CONCLUSION:
Our findings indicate that engaging in acute sprint interval cycling exercise under MH offers a more effective stimulus for enhancing post-exercise glucose regulation in overweight adults. This approach can be deemed a preferred choice for exercise prescription by both exercise practitioners and clinicians aiming to promote metabolic health.

FUNDING: Tee C.C.L is supported by a grant from the National Sports Institute of Malaysia and Swinburne University of Technology, Melbourne, Australia.

REFERENCES:
1) Tee at al. (2023) Sports Med. 52(2):327-348.
2) Tee at al. (2023) Front Physiol. 14:1174926