What happens to athletes' bodies when they eat more fat and less carb for a week?
Effects of fat adaptation and carbohydrate restoration on prolonged endurance exercise.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Athletes ate either a high-fat or high-carb diet for 6 days, then rode bikes for 4 hours and did a 1-hour speed test. Scientists checked what fuel their bodies used.
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Systematic Reviews & Meta-Analyses
Max 100Randomized Controlled Trials
Max 90Cohort Studies
Max 72Case-Control Studies
Max 58Cross-Sectional Studies
Max 44Case Reports & Case Series
Max 30Expert Opinion & Narrative Reviews
Max 526 / 44
Evidence Score
A snapshot of a population at a single point in time. Can identify correlations and prevalence, but cannot determine the direction of cause and effect.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Athletes ate either a high-fat or high-carb diet for 6 days, then rode bikes for 4 hours and did a 1-hour speed test. Scientists checked what fuel their bodies used.
No biological mechanisms were identified in this study. This may be an epidemiological, observational, or survey-based study that reports associations rather than proposing causal biological pathways.
Systematic Reviews & Meta-Analyses
Max 100Randomized Controlled Trials
Max 90Cohort Studies
Max 72Case-Control Studies
Max 58Cross-Sectional Studies
Max 44Case Reports & Case Series
Max 30Expert Opinion & Narrative Reviews
Max 526 / 44
Evidence Score
A snapshot of a population at a single point in time. Can identify correlations and prevalence, but cannot determine the direction of cause and effect.
Publication
Authors
Carey AL, Staudacher HM, Cummings NK, Stepto NK, Nikolopoulos V, Burke LM, Hawley JA
Related Content
Claims (5)
When your body gets used to burning fat for fuel, it becomes better at using fat by turning up the systems that break it down and use it for energy.
For endurance athletes, switching to a high-fat diet for six days and then loading up on carbs doesn’t seem to boost performance in a one-hour cycling test compared to sticking with a high-carb diet.
If endurance athletes eat a high-fat, low-carb diet for just 6 days, their bodies burn way more fat during a long bike ride — about 50 grams more over 4 hours — compared to when they eat lots of carbs, even if they're used to carb-heavy diets.
When endurance athletes eat a high-fat diet for 6 days, their bodies burn less carbs during a long bike ride compared to when they eat a high-carb diet — showing their metabolism switches to using more fat for fuel.
Even after endurance athletes eat lots of carbs for a day, their bodies still burn more fat than usual if they recently spent a week on a high-fat diet.