Research

Energy balance

A ketogenic diet significantly reduces maximal work load and work load at lactate threshold compared to a mixed diet in off-road cyclists, indicating compromised high-intensity performance.

If you are an endurance cyclist, switching to a high-fat, low-carb diet for a month during your base training phase can significantly boost your aerobic capacity (VO2max) and lactate threshold, largely because you lose weight and your body becomes more efficient at burning fat. However, be prepared for a drop in your maximum sprint power and high-intensity efforts, as your body will have less glycogen for those explosive moves. This is a trade-off: better endurance efficiency for less top-end speed.

ModerateRefutesMEDIUM confidence
The max work load and the work load at lactate threshold were significantly higher after the mixed diet.
Adam Zając et al. · Nutrients · 2014

Why this rating

Small sample size (n=8), but statistically significant results.

Source

The Effects of a Ketogenic Diet on Exercise Metabolism and Physical Performance in Off-Road Cyclists

Adam Zając et al. · Nutrients · 2014

DOI 10.3390/nu6072493

crossover · n=8Cited 184×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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