Endurance
The vegetarians outlasted the meat-eaters at Yale in 1907, and newer research agrees
+0.55Aerobic effect size, plant-based vs omnivore
In a famous 1907 Yale study, vegetarians had several times the endurance of meat-eating athletes[1][2]. Modern research agrees: plant-based diets give a moderate boost to aerobic performance with no loss of strength[4], and vegan runners are no slower[8]. You don’t need to eat animals to go the distance.
What the evidence says
The main points first. Every claim is tied to a source below.
In 1907, vegetarians far outlasted Yale’s meat-eating athletes
Irving Fisher’s 1907 study had about 49 people, mostly men: Yale athletes who ate meat, athletes who avoided flesh, and sedentary vegetarians from Battle Creek[1]. Holding their arms out, the meat-eaters averaged about 10 minutes and the abstainers lasted about five times longer[1]. Only two of fifteen flesh-eaters held out past 15 minutes, against twenty-two of thirty-two abstainers, and none of the flesh-eaters reached half an hour, while fifteen abstainers did: nine went past an hour, and one past three hours[3]. On deep knee-bends, the meat-eaters averaged about 383 and the plant-eating athletes about 927[1]. Even the sedentary vegetarians averaged about 535, and one person who had never eaten meat did 2,400 and then went back to nursing duties[3]. Fisher wasn’t a vegetarian; he wrote that the result was “much to my surprise” and concluded that the flesh-eating athletes were “very far inferior in endurance to the abstainers, even the sedentary group[1].” The New York Times reported that Yale’s flesh-eating athletes were beaten[2].
Read full article →Plant-based diets improved aerobic performance and left strength unchanged
Damasceno and colleagues pooled trial data in the British Journal of Nutrition in 2024 and found that plant-based diets had a moderate positive effect on aerobic performance, with an effect size of 0.55[1]. They had no effect on strength or power[1]. Endurance is where carbohydrate, good blood flow, and less visceral fat tend to help most.
Read full article →Vegan women had higher VO2 max and the same strength as omnivores
Boutros and colleagues found that young vegan women who did the same weekly training as omnivores had a higher estimated VO2 max and the same muscle strength[1]. Barnard’s 2019 review on diet and endurance found that a mostly vegan vegetarian diet reduced visceral fat and raised VO2 max even without weight loss[2]. In a marathon the heart is often what limits you, and plant-based diets tend to be good for the heart.
Read full article →Vegan runners are as fast as runners who eat meat
The NURMI study found no difference in best half-marathon or marathon times between vegan, vegetarian, and omnivore recreational runners[1]. Nebl and colleagues found no difference in exercise capacity and called vegan diets a suitable alternative[2], and Stanford’s SWAP-MEAT Athlete study found that athletes’ performance didn’t drop on either whole plant foods or plant-based meats[3]. Just matching meat-eaters disproves the claim that you need meat to go far[2], and a meta-analysis of trials suggests plant-based diets add an advantage on top of that.
Read full article →Articles
Plant-based diets give endurance athletes an edge
A 2024 meta-analysis found that plant-based diets give athletes a moderate boost in aerobic performance with no loss of strength, and vegan runners race as fast as omnivores. At Yale in 1907, the athletes who ate meat were beaten badly in endurance tests, even by vegetarians who spent most of the day sitting.
Read full article →
Sources
Papers and datasets. Each card keeps its caveats, including small samples and single-animal cases.
[1]Yale Medical Journal, 1907 · Small sample
In Fisher’s 1907 Yale tests, athletes who didn’t eat meat far outlasted meat-eaters
In March 1907, Irving Fisher compared meat-eating Yale athletes with athletes who didn’t eat flesh and with sedentary vegetarians, and the flesh-abstainers were far ahead. The meat-eaters held their arms out for about 10 minutes and the abstainers for about five times as long, and in deep knee-bends the meat-eating athletes averaged about 383 and the plant-eating athletes about 927. Fisher wasn’t a vegetarian and said the result surprised him, though the study was small and old, nothing like a modern VO2 lab.
[2]The New York Times, March 22 1907 · Review
In 1907, The New York Times ran the headline “Vegetarians the Stronger”
The New York Times covered Fisher’s Yale tests at the time, reporting that Yale’s flesh-eating athletes had been beaten in severe endurance trials. So the idea that athletes need meat for strength was already contradicted in print in 1907.
[3]NutritionFacts · Review
NutritionFacts on the first studies of vegetarian athletes
NutritionFacts walks through Fisher’s Yale tests, the 1896 Vegetarian Cycling Club, and a 1904 Belgian lifting test in which the plant-eaters reportedly managed about 80% more repetitions, though the English primary source for that test is hard to find. The Yale numbers are the ones that survive in the archives.
[4]British Journal of Nutrition, 2024 · Meta-analysis
Plant-based diets improved aerobic performance without changing strength or power
Damasceno’s meta-analysis found that plant-based diets had a moderate positive effect on aerobic performance (effect size 0.55, 95% CI 0.29–0.81) and no effect on strength or power.
[5]European Journal of Clinical Nutrition, 2020 · Observational
Vegan women had a higher estimated VO2 max than omnivores
Boutros and colleagues compared 56 healthy, young, lean women who trained the same amount, 28 vegans and 28 omnivores. The vegans had a higher estimated VO2 max and no difference in muscle strength, so the vegan diet didn’t hurt their endurance.
[6]Nutrients, 2019 · Review
Barnard on how plant-based diets help endurance athletes
Barnard and colleagues’ review explains that plant-based diets improve blood fats, blood flow, and glycogen storage from carbohydrate, and that a vegetarian, mostly vegan, diet reduced visceral fat and raised VO2 max even without weight loss. It also covers recovery and heart safety, which matter for people who run long distances.
[7]Journal of the International Society of Sports Nutrition, 2019 · Observational
Vegan runners matched omnivores in exercise capacity
Nebl’s team tested ambitious recreational runners and found no significant difference in exercise capacity between vegans, lacto-ovo vegetarians, and omnivores. The authors concluded that a vegan diet can be a suitable alternative, and simply matching the omnivores is enough to disprove the claim that you need meat.
[8]Nutrients, 2023 · Observational
Vegan runners weren’t slower in the NURMI study
In Wirnitzer’s NURMI study of recreational distance runners, best half-marathon and marathon times didn’t differ significantly between omnivores, vegetarians, and vegans once differences in training were accounted for. So 100% plant-based nutrition is compatible with distance running.
[9]Nutrition Journal, 2022 · Clinical
Athletes’ performance didn’t drop on plant-based diets in a Stanford crossover study
In the SWAP-MEAT Athlete study, Roberts and colleagues had recreational athletes rotate through a whole-food plant-based diet, a diet of plant-based meat alternatives, and an animal-based diet. Their performance didn’t drop on either plant diet, contrary to the common claim, though each diet lasted only four weeks.
[10]Nutrients, 2021 · Review
Vegan diets may give endurance athletes an edge, a review finds
Pohl’s review argues that the nutrient mix of vegan and vegetarian diets, with plenty of carbohydrate and antioxidants and benefits for the lining of the blood vessels, could give endurance athletes an advantage, and research hasn’t shown a consistent penalty. Craddock’s 2016 review of older trials found vegetarian diets neither helped nor hurt performance, and a newer meta-analysis found an aerobic advantage.