A study in the Journal of the International Society of Sports Nutrition suggests that athletes can thrive on a variety of different diets. German researchers recruited 76 male and female recreational runners, each of whom was following one of three diets—vegan, lacto-ovo-vegetarian (includes dairy and eggs) or omnivore (includes meat and fish)—with similar calorie intakes.

After the runners exercised to exhaustion on a cycling ergometer, the researchers determined that exercise capacity—as indicated by measures such as maximum power output—was about the same among the three groups. So whether active individuals prefer beef or beans, it appears they can thrive during a sweat session—as long as they get the overall nutrition needed to sustain training.