Author(s): DENG, S., YIN, M.1, CHEN, Z.1, GIRARD, O.2, LI, Y.1, Institution: SHANGHAI UNIVERSITY OF SPORT, Country: CHINA, Abstract-ID: 340

INTRODUCTION:
Obesity is becoming a critical global public health concern [1]. Recently, high-intensity interval training in hypoxia (HIHT) has presented an innovative therapeutic approach to optimize fat loss strategies and mitigate cardiometabolic risks among inactive and obese populations [2, 3]. To date, currently available studies have produced mixed results [4]. This systematic review and meta-analysis aimed to determine the effects of HIHT compared with high-intensity interval training in normoxia (HINT) to improve cardiometabolic health outcomes in sedentary, overweight/obese adults.
METHODS:
A systematic search was conducted on PubMed/MEDLINE, Web of Science, EBSCOhost, Embase, and Cochrane Library databases (up to January 2024) to identify original articles assessing cardiometabolic health outcomes in sedentary and overweight/obese adults following both HIHT and HINT. Subsequently, a meta-analysis was performed to determine the standardized mean difference (SMD) between the effects of HIHT and HINT on cardiometabolic health outcomes.
RESULTS:
Eight studies with a total of 218 participants were included. HIHT induced greater improvement in maximal oxygen uptake (VO2max) (SMD = 0.53; 95% confidence interval [CI]: 0.22, 0.83; I2 = 0%; p < 0.001) compared with HINT. There were no significant differences in fat mass (SMD = -0.01; 95%CI: -0.42, 0.39), systolic blood pressure (SMD = -0.16; 95%CI: -0.54, 0.23), diastolic blood pressure (SMD = 0.02; 95%CI: -0.36, 0.41), triglycerides (SMD = -0.15; 95%CI: -0.45, 0.14), total cholesterol (SMD = 0.27; 95%CI: -0.03, 0.57), glucose (SMD = 0.06; 95%CI: -0.51, 0.64), as well as high-density (SMD = 0.20; 95%CI: -0.17, 0.56) and low-density lipoprotein cholesterol (SMD = 0.07; 95%CI: -0.30, 0.43) between HIHT and HINT.
CONCLUSION:
Based on current evidence, HIHT induces greater VO2max improvements compared with HINT in sedentary and overweight/obese adults. However, due to the limited research, further investigation of this novel nonpharmacological therapeutic intervention is warranted with larger sizes, standardized protocols, and exploration of potential mediators (e.g., exercise intensity, hypoxic severity, sex, and age) to substantiate and expand the evidence across diverse populations.
References:
1. Elmaleh-Sachs A, Schwartz JL, Bramante CT, Nicklas JM, Gudzune KA, Jay M. Obesity Management in Adults: A Review. JAMA. 2023;330(20):2000-2015.
2. Brocherie F, Millet GP. Hypoxic exercise as an effective nonpharmacological therapeutic intervention. Exp Mol Med. 2020;52(3):529-530.
3. Girard O, Matic Girard I, Peeling P. Hypoxic conditioning: a novel therapeutic solution for load-compromised individuals to achieve similar exercise benefits by doing less mechanical work!. Br J Sports Med. 2021;55(17):944-945.
4. Millet GP, Girard O. Editorial: High-Intensity Exercise in Hypoxia: Beneficial Aspects and Potential Drawbacks. Front Physiol. 2017;8:1017.