Impact of pre‐exercise feeding status on metabolic adaptations to endurance‐type exercise training

Abstract

Nutrition and exercise metabolism are vibrant physiological fields, yet at times it feels as if greater progress could be made by better integrating these disciplines. Exercise is advocated for improving metabolic health, in part by increasing peripheral insulin sensitivity and glycaemic control. However, when a modest-to-high carbohydrate load is consumed before and/or during each exercise bout within a training programme, increases in oral glucose insulin sensitivity can be blunted in both men of a healthy weight and those with overweight/obesity. Exercise training-induced adaptation in the energy sensing AMP-activated protein kinase (AMPK) and Rob Edinburgh recently completed a PhD at the University of Bath, having also gained an undergraduate degree in Sport and Exercise Science. His research to date has focused on the effects of nutrient-exercise timings on substrate utilisation during and after exercise, metabolism, and health-related adaptations to exercise. He is passionate about ways we can make exercise more efficacious for health. Francoise Koumanov is a Lecturer (Assistant Professor) at the University of Bath. Her research focuses on molecular signalling processes of glucose and insulin in physiological and pathophysiological states and aims to elucidate the roles of exercise and GLUT4 trafficking in the pathophysiology of insulin resistance. Javier Gonzalez is Reader (Associate Professor) at the University of Bath. His research focuses on interactions between nutrition and exercise in health and disease and explores the role of carbohydrate availability in the regulation of energy balance, metabolic health and sports performance.

Comparing Acute, High Dietary Protein and Carbohydrate Intake on Transcriptional Biomarkers, Fuel Utilisation and Exercise Performance in Trained Male Runners

“…Moderate to high intensity endurance exercise is known to increase AMPK activity due to metabolic stress and accelerated ATP demand. In the presence of adequate carbohydrate provision, the up-regulation in AMPK and PPAR mRNA observed in the current study may be associated with higher GLUT-4 and hexokinase activity [37] as opposed to mitochondrial biogenesis. As such, the combination of higher carbohydrate intake, coupled with regular endurance training may have favoured adaptations associated with glucose metabolism and sustained carbohydrate oxidation rates.…”

Effects of Low/Medium-Intensity Exercise on Fat Metabolism after a 6-h Fast

“…Fasting before exercise may be used to increase the proportion of fat metabolism and to lose weight, but the effect is not obvious in the long term [ 28 ]. Additionally, past research has shown that fasting before exercise can improve insulin sensitivity [ 29 , 30 ]. However, previous studies lacked an investigation of exercise after fasting for less than 12 h. Our research has verified that fasting for 6 h can also increase fat metabolism, which serves as a reference for exercise program design.…”

Novel dietary approaches to appetite regulation, health and performance

“…Evidence is developing to indicate that performing exercise with lower carbohydrate and/or higher fatty acid availability may enhance some adaptations to exercise training. One of the primary metabolic adaptations to regular exercise training is an increase in insulin sensitivity, and major mechanisms contributing to this adaptation include molecular changes in skeletal muscle (Edinburgh et al 2022). With each bout of exercise, a number of pathways in skeletal muscle are activated (e.g.…”

“…There is also a current lack of long-term (>12 weeks) data to understand the chronic responses to time-restricted eating. Edinburgh et al (2022) review the responses to extended overnight fasting within the context of prescribed exercise. Evidence is developing to indicate that performing exercise with lower carbohydrate and/or higher fatty acid availability may enhance some adaptations to exercise training.…”

“…One of the primary metabolic adaptations to regular exercise training is an increase in insulin sensitivity, and major mechanisms contributing to this adaptation include molecular changes in skeletal muscle (Edinburgh et al . 2022). With each bout of exercise, a number of pathways in skeletal muscle are activated (e.g.…”