Fat adaptation science: low-carbohydrate, high- fat diets to alter fuel utilization and promote training adaptation.

The effect of manipulating an individual's habitual diet on skeletal muscle fuel utilization has been of longstanding interest to scientists, and it is now well established that changes in dietary intake that alter the concentration of blood-borne substrates and hormones cause substantial perturbations in the macronutrient storage profile of muscle and exert profound effects on rates of substrate oxidation during exercise. Only recently, however, has it become appreciated that nutrient-exercise interventions can modulate many contraction- induced responses in muscle, and that fuel availability per se provides a 'trigger' for adaptation. Consumption of low-carbohydrate, high- fat diets in the face of endurance training alters patterns of fuel utilization and subsequent exercise responses. Human studies show how low-carbohydrate, fat-rich diets interact with specific contractile stimulus to modulate many of the acute responses to exercise, thereby promoting or inhibiting subsequent training adaptation.