Eating fat for a week makes your body burn fat better, but you can't sprint as hard
Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Cyclists ate either a high-fat or high-carb diet for 6 days, then loaded up on carbs for 1 day. They rode 100 km and did sprints. The high-fat diet made their bodies better at burning fat, but they couldn't go as fast in the sprints.
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
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Max 90Cohort Studies
Max 72Case-Control Studies
Max 58Cross-Sectional Studies
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Evidence Score
Participants are randomly assigned to treatment or control groups, minimizing bias. Considered the gold standard for testing whether an intervention causes an effect.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Cyclists ate either a high-fat or high-carb diet for 6 days, then loaded up on carbs for 1 day. They rode 100 km and did sprints. The high-fat diet made their bodies better at burning fat, but they couldn't go as fast in the sprints.
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 550 / 90
Evidence Score
Participants are randomly assigned to treatment or control groups, minimizing bias. Considered the gold standard for testing whether an intervention causes an effect.
Publication
Authors
Havemann L, West SJ, Goedecke JH, Macdonald IA, St Clair Gibson A, Noakes TD, Lambert EV
Related Content
Claims (6)
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.
If elite male cyclists eat a super high-fat diet for six days and then carb-load for one day, they’ll perform worse in sprints—even though they don’t feel more tired, their heart rate doesn’t change, and their muscles fire the same way.
If elite male cyclists eat a super high-fat diet for 6 days before carb-loading for a day, they’ll feel just as fast over a long 100-km ride — but they’ll have less power for short, intense sprints compared to when they eat a high-carb diet first.
If male cyclists eat a super high-fat diet for six days, their body's 'fight or flight' system might get a bit more active — and that change doesn’t go away right after they start eating carbs again.
If elite male cyclists eat a super high-fat diet for six days, their bodies get better at burning fat for fuel — even when they switch back to eating lots of carbs for a day.