Neither autophagy nor exercise training mode affect exercise-induced beneficial adaptations in high fat-fed mice

Abstract

Exercise mitigates obesity-associated pathologies; however, there is controversy regarding optimal exercise interventions. Autophagy, is known to decrease during obesity and is an important moderator for exercise adaptations. Purpose: To investigate individual and combined effects of different exercise interventions and autophagy inhibition on exercise adaptations during obesity. Methods: C57BL/6J mice initiated 45% high fat diet at 8 weeks of age. After 6 weeks of diet, animals were divided into moderate (MOD) or high intensity interval training interventions (HIIT), animals were further divided into autophagy inhibition or vehicle conditions (n = 10/group). Animals exercised and autophagy was inhibited 3X/week by NSC185058 injections, thereby blocking autophagosome formation. Interventions continued for 4 weeks. Results: High fat diet impaired glucose handling ∼17%; exercise interventions normalized glucoregulation to pre-high fat diet levels, without differences between any interventions. High fat diet induced ∼25% decrease in aerobic capacity, which returned to baseline after exercise interventions, with no differences between any interventions. No effects of autophagy inhibition were noted. Conclusions: HIIT and MOD training confer similar health-related adaptations. Keywords: Insulin resistance, Exercise capacity, Glucose tolerance, Obesity