Is A Vegan Diet Detrimental To Endurance And Muscle Strength?, European Journal of Clinical Nutrition, April 2020
In the general population, there is a popular belief that a vegan diet may be associated with a lower exercise performance due to the lack of certain nutrients in vegan individuals. Thus, the purpose of the present study was to examine endurance and muscle strength differences between vegan and omnivore participants.
We studied 56 healthy young lean physically active women. Participants were classified as vegan (n = 28) or omnivore (n = 28) based on their eating habits. All volunteers followed either a vegan or an omnivore diet for at least 2 years. Anthropometric measurements, body composition, estimated maximal oxygen consumption (VO2 max), a submaximal endurance test (70% of VO2 max), muscle strength (leg and chest press), and dietary factors were measured.
Both groups were comparable for physical activity levels, body mass index, percent body fat, lean body mass, and muscle strength. However, vegans had a significantly higher estimated VO2 max (44.5 ± 5.2 vs. 41.6 ± 4.6 ml/kg/min; p = 0.03, respectively) and submaximal endurance time to exhaustion (12.2 ± 5.7 vs. 8.8 ± 3.0 min; p = 0.007, respectively) compared with omnivores.
The results suggest that a vegan diet does not seem to be detrimental to endurance and muscle strength in healthy young lean women. In fact, our study showed that submaximal endurance might be better in vegans compared with omnivores. Therefore, these findings contradict the popular belief of the general population.
One potential mechanism that could explain the greater level of endurance performance in vegans may be a higher amount of carbohydrate intake. Evidence has suggested that greater carbohydrate intake may be associated with a better endurance performance  and this could be due to higher muscle glycogen storage . It should be noted that, in the present study, carbohydrate intake was significantly higher in vegans compared with omnivores. which is in line with previous research showing that vegetarians/ vegans consume higher amounts of carbohydrate [9–11].
Other potential mechanisms that may explain the better endurance performance in vegans could be due to favorable oxidative stress and inflammation profiles.