Fat and carbohydrate for exercise.
OBJECTIVE
To examine the results of new investigations that look at the efficacy of nutrient/training strategies on metabolism and athletic performance.


RESULTS
'Dietary periodization' involves the manipulation of macronutrient intake in association with changes in physical training. Such interventions have a major effect on altering patterns of fuel utilization during exercise; however, they often fail to enhance performance capacity. In contrast, the ingestion of a combination of different types of carbohydrate during exercise results in high rates of muscle glucose oxidation (1.5 g/min) and can improve intense, short-duration (approximately 60 min), and prolonged (>90 min) submaximal steady-state exercise, either by metabolic or neural mechanisms.


CONCLUSIONS
Further investigation into the responses of specific nutrient/training strategies on metabolic and cellular signaling pathways is warranted to determine the underlying mechanisms by which such interventions exert their effect. Such studies, however, should be coupled with investigations that assess the outcomes of these responses on the 'real life' training adaptations in athletes.
Burke
Louise M
LM
Department of Sports Nutrition, Australian Institute of Sport, Belconnen, ACT, Australia. louise.burke@ausport.gov.au
Hawley
John A
JA
D000222:Adaptation, Physiological; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage* / Q000378:metabolism; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006801:Humans; D018482:Muscle, Skeletal / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects*; D010807:Physical Endurance / Q000187:drug effects* / Q000502:physiology
D004040:Dietary Carbohydrates; D004041:Dietary Fats