A Single Bout of One-Legged Exercise to Local Exhaustion Decreases Insulin Action in Nonexercised Muscle Leading to Decreased Whole-Body Insulin Action

Abstract

A single bout of exercise enhances insulin action in the exercised muscle. However, not all human studies find that this translates into increased whole-body insulin action, suggesting that insulin action in rested muscle or other organs may be decreased by exercise. To investigate this, eight healthy men underwent a euglycemic-hyperinsulinemic clamp on 2 separate days: one day with prior one-legged knee-extensor exercise to local exhaustion (∼2.5 h) and another day without exercise. Whole-body glucose disposal was ∼18% lower on the exercise day as compared with the resting day due to decreased (∼37%) insulin-stimulated glucose uptake in the nonexercised muscle. Insulin signaling at the level of Akt2 was impaired in the nonexercised muscle on the exercise day, suggesting that decreased insulin action in nonexercised muscle may reduce GLUT4 translocation in response to insulin. Thus, the effect of a single bout of exercise on whole-body insulin action depends on the balance between local effects increasing and systemic effects decreasing insulin action. Physiologically, this mechanism may serve to direct glucose into the muscles in need of glycogen replenishment. For insulin-treated patients, this complex relationship may explain the difficulties in predicting the adequate insulin dose for maintaining glucose homeostasis following physical activity.

The insulin‐sensitizing effect of a single exercise bout is similar in type I and type II human muscle fibres

“…2017; Steenberg et al . 2019, 2020), as also observed in the present study. As stated above, we speculate that the function of the maintained phosphorylation of TBC1D4 Ser704 in humans may relate to the decreased glycogen content and increased AMPK activity in the recovery from exercise.…”

“…In all human cohorts studied so far, muscle TBC1D4 Ser704 phosphorylation is enhanced 4-5 h into recovery from exercise (Pehmøller et al 2012;Sjøberg et al 2017;Hingst et al 2018;Steenberg et al 2019Steenberg et al , 2020. In a few of these studies (Pehmøller et al 2012;Sjøberg et al 2017), subsequent insulin stimulation increases this phosphorylation to even higher levels and to higher levels than the prior rested muscle.…”

“…2015; Steenberg et al . 2019, 2020). The physiological advantage might relate to a faster and, under some circumstances, higher muscle glycogen replenishment in the prior exercised muscle once glucose becomes available (Bergström & Hultman, 1966; Hingst et al .…”

“…2007; Steenberg et al . 2019, 2020). However, skeletal muscle is a heterogeneous tissue composed of different fibre types.…”

A single bout of exercise improves vascular insulin sensitivity in adults with obesity

“…Several studies have highlighted that exercise increases insulin-stimulated peripheral glucose uptake across the glucose tolerance spectrum (16,17). Interestingly, these benefits can be observed in the absence of weight loss (18) and following just a single bout (19,20), although not all studies agree (21). However, the effects of acute exercise on vascular insulin sensitivity in conduit arteries and/or skeletal muscle capillaries are less known.…”