Lipid metabolism links nutrient-exercise timing to insulin sensitivity in men classified as overweight or obese
Research output: Contribution to journal › Article › peer-review
Colleges, School and Institutes
- University of Bath
- Medical University of Bialystok, Poland
- University College London
Context: Pre-exercise nutrient availability alters acute metabolic responses to exercise, which could modulate training responsiveness.
Objective: To assess acute and chronic effects of exercise performed before versus after nutrient ingestion on whole-body and intramuscular lipid utilization and postprandial glucose metabolism.
Design: (1) Acute, randomized, crossover design (Acute Study); (2) 6-week, randomized, controlled design (Training Study).
Setting: General community.
Participants: Men with overweight/obesity (mean ± standard deviation, body mass index: 30.2 ± 3.5 kg·m -2 for Acute Study, 30.9 ± 4.5 kg·m -2 for Training Study).
Interventions: Moderate-intensity cycling performed before versus after mixed-macronutrient breakfast (Acute Study) or carbohydrate (Training Study) ingestion.
Results: Acute Study -exercise before versus after breakfast consumption increased net intramuscular lipid utilization in type I (net change: -3.44 ± 2.63% versus 1.44 ± 4.18% area lipid staining, P < 0.01) and type II fibers (-1.89 ± 2.48% versus 1.83 ± 1.92% area lipid staining, P < 0.05). Training Study -postprandial glycemia was not differentially affected by 6 weeks of exercise training performed before versus after carbohydrate intake (P > 0.05). However, postprandial insulinemia was reduced with exercise training performed before but not after carbohydrate ingestion (P = 0.03). This resulted in increased oral glucose insulin sensitivity (25 ± 38 vs -21 ± 32 mL·min -1·m -2; P = 0.01), associated with increased lipid utilization during exercise (r = 0.50, P = 0.02). Regular exercise before nutrient provision also augmented remodeling of skeletal muscle phospholipids and protein content of the glucose transport protein GLUT4 (P < 0.05).
Conclusions: Experiments investigating exercise training and metabolic health should consider nutrient-exercise timing, and exercise performed before versus after nutrient intake (ie, in the fasted state) may exert beneficial effects on lipid utilization and reduce postprandial insulinemia.
|Number of pages||17|
|Journal||Journal of Clinical Endocrinology and Metabolism|
|Early online date||19 Oct 2019|
|Publication status||Published - Mar 2020|