The Effects of Macronutrient and Energy Availability on Metabolic Responses to Exercise: Implications for Training Adaptation
type: CreativeWork
description: Traditional nutritional guidelines for endurance athletes typically advise high carbohydrate (CHO) availability before, during, and after exercise in order to support high training intensities and volumes. However, accumulating data now suggest that restricting CHO and/or energy availability around training may augment the exercise-induced cell signalling responses associated with oxidative adaptations in human skeletal muscle. In addition to the manipulation of CHO availability, there is also a growing interest in the role of increased dietary fat intakes in augmenting components of training adaptation. The aim of this thesis was to therefore assess the effects of macronutrient and energy availability on the regulation of molecular signalling pathways associated with mitochondrial biogenesis, lipid metabolism and muscle protein synthesis. A secondary aim was to also examine the acute effects of CHO and energy restriction on physiological markers associated with the syndrome of Relative Energy Deficiency in Sport (RED-S). Study 1 (Chapter 4) examined the effects of reduced CHO but high post-exercise fat availability on the activation of cell signalling kinases and expression of genes with roles in the regulation of mitochondrial biogenesis, lipid metabolism and muscle protein synthesis. In a repeated measures design, ten male participants completed a morning high intensity interval (HIT) running session (AM-HIT) followed by an afternoon steady state running session (PM-SS), under conditions of either high CHO (HCHO), or isocaloric low CHO but high fat (HFAT) availability in the post-exercise recovery period. Muscle glycogen was lower (P<0.05) at 3 (251 vs 301 mmol.kg-1dw) and 15 h (182 vs 312 mmol.kg-1dw) post afternoon exercise in HFAT compared to HCHO, however comparable increases (all P<0.05) in PGC-1α, p53, CS, Tfam, PPAR and ERRα mRNA were observed in HCHO and HFAT in response to exercise. AMPK-α2 activity was not increased post-exercise in either condition (P=…
abstract: Traditional nutritional guidelines for endurance athletes typically advise high carbohydrate (CHO) availability before, during, and after exercise in order to support high training intensities and volumes. However, accumulating data now suggest that restricting CHO and/or energy availability around training may augment the exercise-induced cell signalling responses associated with oxidative adaptations in human skeletal muscle. In addition to the manipulation of CHO availability, there is also a growing interest in the role of increased dietary fat intakes in augmenting components of training adaptation. The aim of this thesis was to therefore assess the effects of macronutrient and energy availability on the regulation of molecular signalling pathways associated with mitochondrial biogenesis, lipid metabolism and muscle protein synthesis. A secondary aim was to also examine the acute effects of CHO and energy restriction on physiological markers associated with the syndrome of Relative Energy Deficiency in Sport (RED-S). Study 1 (Chapter 4) examined the effects of reduced CHO but high post-exercise fat availability on the activation of cell signalling kinases and expression of genes with roles in the regulation of mitochondrial biogenesis, lipid metabolism and muscle protein synthesis. In a repeated measures design, ten male participants completed a morning high intensity interval (HIT) running session (AM-HIT) followed by an afternoon steady state running session (PM-SS), under conditions of either high CHO (HCHO), or isocaloric low CHO but high fat (HFAT) availability in the post-exercise recovery period. Muscle glycogen was lower (P<0.05) at 3 (251 vs 301 mmol.kg-1dw) and 15 h (182 vs 312 mmol.kg-1dw) post afternoon exercise in HFAT compared to HCHO, however comparable increases (all P<0.05) in PGC-1α, p53, CS, Tfam, PPAR and ERRα mRNA were observed in HCHO and HFAT in response to exercise. AMPK-α2 activity was not increased post-exercise in either condition (P=…
author: Hammond, K
keywords: RC1200 Sports Medicine
date published: 2019-10
date modified: 2026-07-24T06:30:31Z
provider: Liverpool Jon Moores University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Liverpool John Moores University

PropertyValue
property ID: DOI
value: 10.24377/LJMU.t.00011711