The cell damage may be caused by reactive oxygen species, which become more abundant when the body gets flooded with sugar on a low-carb diet, says study author Jonathan Little, Ph.D., associate professor of health and social development at the University of British Columbia in Canada. The effects have implications for your workouts and more: Your muscles may not get as much blood during exercise (since that’s driven by dilation) and you could feel colder in general (constriction helps you stay warm). Plus, this type of breakdown is a risk factor for heart disease—even if you’re otherwise fit and healthy.
Though the cells returned to full function once blood sugar levels dropped off, regular cheat meals can lead to long-lasting damage, Little says.
The bottom line:
If you’re on the keto diet, you shouldn’t exceed the daily carb limit of 50 grams more than three times a year. When you do, consider a post-meal workout. “Exercising can reduce the spike that happens after you eat because your working muscles use the glucose to fuel contractions,” Little explains.