Research

Hormonal

Long-term LCHF diet adaptation may lead to the early development of central fatigue during exercise due to elevated blood concentrations of non-esterified fatty acids (NEFA) and ammonia.

Be aware that switching to a low-carb diet might make you feel mentally tired or 'lethargic' during exercise, especially early on. This is due to changes in blood chemistry (fatty acids and ammonia) affecting your brain. This is a known potential downside of LCHF that may counteract physical benefits.

ModerateRefutesMEDIUM confidence
However, elevated blood concentrations of non-esterified fatty acids and ammonia during exercise after LCHF diets may lead to early development of central fatigue.
Chen‐Kang Chang et al. · Journal of Human Kinetics · 2017

Why this rating

The paper cites pilot studies and mechanisms but states there is a knowledge gap regarding long-term adaptation effects on central fatigue.

Source

Low-Carbohydrate-High-Fat Diet: Can it Help Exercise Performance?

Chen‐Kang Chang et al. · Journal of Human Kinetics · 2017

DOI 10.1515/hukin-2017-0025

narrative_reviewCited 69×
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DOI resolved against Crossref · corpus check 2026-06-10

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