Recreational runners performed similarly on plant-based and omnivore diets.
Resistance trainers saw no statistically significant difference in strength.
Researchers say longer studies are needed to understand the effects over time.
For people who exercise regularly, switching to a plant-based diet can raise an important question: Will cutting back on meat affect performance?
A new study from researchers at four universities suggests that, for recreational athletes, the answer may be no — at least over the short term. The study found no statistically significant differences in endurance or strength when participants followed plant-based and omnivore diets for four weeks each.
The research comes as athletes and other active people navigate conflicting claims about whether plant-based diets can provide enough protein and calories to support exercise. Rather than looking at professional athletes, researchers focused on recreational college athletes who regularly used university dining halls.
“Popular social media claims frequently spread misinformation that plant-based diets fail to provide enough calories or protein to meet the demands of exercise,” researcher Peggy Policastro said in a news release.
“The study specifically sought to test these claims by examining recreational student athletes who rely on university dining halls for most of their daily meals.”
How researchers compared the diets
The study included 36 undergraduate students from Rutgers University, Stanford University, Vanderbilt University and the University of Reading in England. Sixteen participants were recreational runners, while 20 were resistance trainers. All exercised three or four times a week.
Each participant completed two four-week diet phases in randomly assigned order. During the omnivore phase, participants were asked to eat at least two servings of animal protein each day. During the plant-based phase, they replaced meat with at least two servings of plant protein, such as beans, tofu, or plant-based meat alternatives.
Participants tracked their food intake at least three days a week and were asked to maintain their usual exercise routines. Runners completed a 12-minute run, measuring how far they could travel, while resistance trainers completed three-repetition maximum tests for the chest press, lat pulldown, and leg press.
What the results mean for consumers
The runners covered an average of nearly 2,658 meters during the omnivore phase and about 2,622 meters during the plant-based phase — a difference of roughly 36 meters. Resistance trainers had a combined strength measurement that was about 4% lower during the plant-based phase. Neither difference was statistically significant.
There were nutritional differences between the diets. Participants consumed about 71 grams of protein per day during the plant-based phase, compared with 103 grams during the omnivore phase.
The plant-based diet also contained more carbohydrates, fiber, iron, and calcium, while the omnivore diet contained more saturated fat, cholesterol, and vitamin B12. Reported calorie intake was similar.
“This is important because it shows that everyday athletes can safely choose plant-based foods without worrying about harming their fitness or strength goals,” Policastro said. “These findings provide evidence-based support for colleges to comfortably expand healthy and environmentally friendly plant-based menu options for their active student populations.”
However, it’s also important to note that the study was small and lasted only eight weeks. The researchers noted that it cannot determine how plant-based eating might affect elite athletes or performance, muscle development, and recovery over months or years.