How Tough Are Vegans?

There are a variety of beliefs and myths about plant-based diets. One commonly held belief about vegans and vegetarians is that they have less muscle mass and worse endurance than their omnivore counterparts. You may have seen a movie or TV show where a person on a plant-based diet has had their strength questioned. On an episode of How I Met Your Mother, for example, a vegan character is told she may need more protein during dinner. This example, among many others, and countless anecdotes among veg*ns themselves, shows us how common this stereotype is in our culture. But how does this belief hold up to scrutiny?

In this study, researchers conducted a study to try and answer this question. They enrolled 56 young women, half vegan and half omnivore, to come to a lab to have their physical health tested. Then, the researchers would compare the two groups to see if there were any significant differences. All women in the study were between 18 and 35 years old, had typical body mass indexes, and had active lifestyles. 

The researchers wanted to make sure that they were making fair comparisons between groups so they could pinpoint diet as the key variable. Five measures were taken: estimated VO₂ max, upper body muscle strength, lower body muscle strength, body composition, and submaximal endurance. The reason they took so many measures was so that they could have a complete picture of what they were trying to get at: endurance and muscle strength in vegans and omnivores. One measure would not be enough to paint the full picture. Researchers also asked participants to keep a journal of their food intake to make sure that everyone was actually a vegan or an omnivore. Also worth noting is that the vegans had been on a plant-based diet for a few years on average.

The results show some pretty good news for vegans. They found that, in terms of body composition, both groups were of similar body weight, body mass index, total fat percentage, and total lean body mass. Estimated VO₂ max, a measure of endurance, was higher in the vegan group than in the omnivore group. Vegans also performed significantly higher on the submaximal endurance test. There were no differences observed for general physical activity or in lower body muscle strength. The vegan group, however, did show a slightly lower (but non-significant) upper body muscle strength. Interestingly, researchers also found that vegans tended to have more intake of vitamin C, dietary fiber, iron, and magnesium. On the other hand, vegans had noticeably less intake of vitamin D and vitamin B12, while also consuming lower amounts of saturated fat. 

The results from this study imply that a vegan diet doesn’t necessarily do harm to the endurance and muscle strength of young, active women. Some measures of endurance, like estimated VO₂ max, were actually higher in the vegan groups. This is similar to other research that has shown a higher level of estimated VO₂ max in young vegetarian women. One potential explanation of this is the amount of carbohydrates consumed, which tends to be higher in vegan and vegetarians. Future research should focus on vegans, as a lot of studies have been done on vegetarians and meat-eaters. 

Overall, research like this allows animal advocates to debunk certain stereotypes about plant-based diets. While people should still be sensitive to their dietary needs (like Vitamins D and B-12), the idea that vegans are physically weaker than their meat-eating counterparts may not be true, at least for the cohort studied here. Research like this, along with cultural items like the film The Game Changers, have the potential to create new paradigms about plant consumption.  Advocates can use this information in their conversations with people worried that the plant-based diet will affect their strength or endurance.