Living high-training low model promotes increased spontaneous physical activity, reduced adiposity and maintenance of fat-free mass in C57BL/6J mice

Researchers have extensively studied how hypoxia affects physiological variables, with training models like "live high - train low" (LH-TL) proposed by Levine & Stray-Gundersen in 1997 to improve athletic performance. Although well-known, few studies use animal models for more in-depth analyses than human studies allow. This study investigated the effects of aerobic training on adiposity, spontaneous physical activity (SPA), and food and water intake in C57BL/6J mice housed in normoxic (Nx) or hypoxic (Hx) conditions for 8 weeks. Mice were divided into trained (T) and sedentary (S) groups, with 10 mice each. Hx animals were kept in normobaric hypoxia (FiO₂=14.5%) for 18 h/day. Training was done at 80% critical velocity, 5 times/week in normoxia. The T groups had lower SPA, especially the Hx-T group, which showed higher food and water intake, reduced fat, and a higher fat-free mass/carcass fat mass ratio. Findings suggest exercise and hypoxia may help combat obesity.