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Other animals
Within mammals, exercise training produces similar effects to humans, including in dogs and rodents. A number of studies of both rodents and humans have demonstrated that individual differences in both ability and propensity for exercise (i.e., voluntary exercise) have some genetic basis. Several studies of rodents have demonstrated that maternal or juvenile access to wheels that allow voluntary exercise can increase the propensity to run as adults. These studies further suggest that physical activity may be more "programmable" (for discussion, see Thrifty phenotype) than food intake. When rodent running wheels are placed outside, wild mice will voluntarily use them for comparable durations to laboratory mice, despite lack of any prior experience with these devices. . Artificial selection experiments on mice has shown significant heritability in voluntary exercise levels, and "high-runner" lines show differences in VO2max , hippocampal neurogenesis , and muscle morphology. The effects of sprint-speed training are less well-studied, though there is a negative correlation between artificial selection for endurance and sprint speed.

The effects of various exercise training types are heterogeneous across non-mammals, and sometimes inconsistent. No effect of endurance training has been found in most studies of lizards (but see ), leading them to be termed "metabolically inflexible". Indeed, damage from overtraining may occur following weeks of forced treadmill exercise in lizards. Sprint training has never been found to have an effect in lizards.

While studied less often, frogs show modest improvements with exercise. Exercise training in fish shows some minor improvements on endurance, but far less than seen under comparable training regimes in mammals.

Among archosaurs, both crocodiles and birds show improvements in aerobic capacity following exercise. Eared grebes present an extreme version of this effect in wild populations, with prolonged periods of low exercise leading to large losses in flight muscle mass and consequent loss of flight ability; subsequent voluntary exercise bouts lead to full recovery of both muscle mass and sufficient flight ability for migration.