Are Vegetarian Athletes Weaker?

A new study shows that meat-eating athletes have no advantage when it comes to cardio or strength training. Getty Images

Vegetarian diets have so many proven health benefits, but will ditching meat tank your training? Not at all, finds a new Arizona State study, one of the first to answer this question. If you do vegetarianism right, you can build just as much cardiorespiratory fitness and strength.

Researchers recruited 70 elite endurance athletes — 27 vegetarians and 43 omnivores — and tracked their food intake, including protein powders and other caloric supplements, for one week. Then they took the participants’ body measurements. Although the vegetarians weighed less than the omnivores, both groups had almost equal body-mass indexes and percentage of lean muscle mass.

Next, to assess the athletes’ cardiorespiratory fitness, they measured their VO2 max during treadmill runs. The vegetarian men proved just as fit as the meat-eating guys, while the vegetarian women actually had 13 percent greater VO2 max scores than their omnivore counterparts. And to the researchers’ surprise, strength, as measured by peak torque during leg extensions, was equal for all men and women.

“I expected cardiorespiratory fitness to be about the same since lots of endurance athletes say their performance has improved since going vegetarian,” says lead study author Heidi Lynch. “Now this study backs that. I was more surprised about strength, because people often think they need meat to get big and strong.”

Of course, the key nutrient that meat delivers is protein, essential to building muscle. But according to these findings, if you get enough protein from plant sources such as soy, quinoa, and nuts, you shouldn’t need meat to gain strength. “Both groups were consuming amounts of protein that fell within the range of what sports dietitians recommend,” Lynch says. “The vegetarians got 1.2 grams per every kilogram of body weight while the omnivores consumed 1.4 grams, so not much more. This shows you can still get adequate protein from a plant-based diet.”

The vegetarians consumed more total grams of carbohydrates than the meat eaters; carbs also made up a higher percentage of their total caloric intake. Both factors may benefit athletic performance, Lynch says, especially in distance running, cycling, triathlon, and other endurance sports. As seen with the vegetarian women in the study, who had higher VO2 max scores, the perks may stem from better fuel availability.

“Perhaps by having a higher carb intake, you have better glycogen storage, which could improve training and benefit VO2 max,” Lynch theorizes. She assumes the same would happen with men but it just wasn’t evident in this study because the guys had a wider range of body sizes.

Besides being sufficient for increasing fitness and strength, vegetarian diets have been linked to healthier hearts, less cancer, and longer lifespans. Plus, they’re way better for the planet. “A big reason why I’m investigating this is I’m so interested in the sustainability aspect of nutrition,” Lynch says. “Plants use less land and water resources and produce fewer greenhouse gases. I wanted to know whether an athlete can maintain athletic performance and strength when eating in a sustainable manner.” Looks like the answer is a resounding yes.