Have you noticed? Plant-based eating is a red-hot trend these days for elite professional athletes. From tennis pro Venus Williams to Olympic skating medalist Meaghan Duhamel, ultramarathoner Scot Jurek and numerous NFL players, the list of plant-based athletes grows longer by the day.
Is this just the latest fad or is there something more to it? What does the science say?
Expert Interview: Sports Dietician Susan Levin
Plant-Based Cooking spoke with sports dietician Susan Levin, co-author of a recently-published scientific review on the benefits of a plant-based diet for athletes, “Plant-Based Diets for Cardiovascular Safety and Performance in Endurance Sports.” The review was published in the journal “Nutrients” in January.
Levin is director of nutrition education for the Physicians Committee for Responsible Medicine, a nonprofit research and advocacy organization focused on preventive medicine and promotion of a plant-based diet which was founded by plant-based pioneer Dr. Neal Barnard. Levin is a regular contributor to U.S. News & World Report.
Five Ways a Plant-Based Diet Enhances Athletic Performance
Leaner Body Mass
Research tells us that a plant-based vegan diet reduces body fat, even without restricting calories or portion sizes. Reduced body fat, Levin said, is associated with increased aerobic capacity which enables an athlete to outperform someone with lower aerobic capacity. Aerobic capacity refers to the maximum amount of oxygen the body uses during maximal exercise. The greater an athlete’s aerobic capacity the faster an athlete can go during endurance sports.
“People who eat vegan diets tend to be leaner, and by that I mean less body fat, which may be directly beneficial for athletic performance. The low-fat high fiber content of plant foods means you’re consuming fewer calories. If you reduce the energy density of your food, you’re going to lose weight if you need to lose weight,” Levin said.
“Eating plant-based carbohydrate-centric meals also increases your metabolism. When you eat food, your metabolism goes up to digest that food. But when you eat low-fat vegan food, your metabolism goes up about 16 percent more compared with the person who ate whatever. That might not sound like that much, but if you’re eating low-fat plant-based all the time, every meal, you’re always getting that extra burn,” she said.
Increased Blood Flow
Blood flow is really important to an athlete, Levin said.
“A high-fat diet can make the blood thicker or more viscous, and that degrades performance because less oxygen reaches the muscles. If you eat a low-fat plant-based diet, studies show it helps improve blood flow, it thins the blood if you will. People who follow the ‘strictest’ plant-based diets have the greatest reduction in blood viscosity,” Levin said. “The more fluid your blood the more oxygen will reach your muscles and in theory that would help with athletic performance.”
There are some pretty good studies out there that show that if you eat even just one single high-fat meal “suddenly everything goes wrong,” Levin said – blood gets thicker, triglycerides shoot up, blood flow is greatly reduced.
“One high-fat meal can impair arterial function for hours,” she said. There’s imminent danger from a high-fat meal and imminent advantage from a low-fat plant-based meal.
Which would you choose?
Who hasn’t had muscle aches and pains after working out?
According to Levin’s co-authored study, “… Acute bouts of intense exercise can elicit an inflammatory response and contribute to delayed-onset muscle soreness. This condition, manifested by pain, reduced muscular performance, and impaired recovery, is more common in untrained individuals and after eccentric (new or unusual) muscle activity.”
What if eating a plant-based diet could help reduce these symptoms?
“A plant-based diet appears to be a helpful part of a strategy to reduce inflammation,” the authors continue.
There are several reasons why a plant-based diet reduces inflammation, Levin said. For starters, plants are rich in antioxidants and phytochemicals that reduce inflammation. They’re also low in inflammatory fats and tend to have helpful ratios of omega-3 to omega-6 essential fatty acids, of which omega-3 fatty acids are anti-inflammatory.
Reduced Recovery Time
When it comes to plant-based athletic recovery, there’s apparently not a lot of research yet. At this point it’s mostly anecdotal, Levin said, or you can just assume that if you have better blood flow and reduced inflammation that you’re going to have a better recovery.
“Anecdotally you hear from professional athletes all the time where recovery is a performance factor that might not apply to someone who just runs four miles a day. It’s very different when you’re an elite athlete. For example, someone who trains every day as his or her job who recovers faster can train more. I know a triathlete who follows a vegan diet and wins – he explained ‘If I can train seven days a week because I recover so fast, I am that much better prepared for a race than my counterpart who can only train six days because he needs to rest a day.’
“That kind of recovery actually is what allows some of these athletes to perform better and win more, and to them, that’s obviously essential,” Levin said.
And more good news: the anti-inflammatory effect of plants is also going to help joints and other body parts that you’re using excessively.
Improved Energy (Glycogen) Reserves for Better Endurance
Carbs, Levin said, are the primary fuel for an athlete, as they are most easily converted into glycogen by the body. Glycogen is a back-up fuel stored by the liver and muscles and released as the body needs energy during endurance sports. Maximum glycogen reserves would allow someone to run for about an hour and a half without eating. When glycogen runs out you “hit a wall” or you keep eating while you’re performing.
And while it’s true that the body can also convert protein and fat to glycogen, it’s a much more difficult process.
“Carbs should, of course, be most of your fuel with adequate protein, not more than you need, and then the rest can come from fat. But carbs should definitely be the focus,” Levin said. Eating more carbs ensures that you’re maximizing your glycogen reserves.
“People who follow vegan diets on average consume more carbohydrates than people who follow vegetarian diets and of course the omnivores’ diets tend to be the least amount of carbohydrates. You’ve already set yourself up by eating a vegan diet to be consuming the right macronutrient profile typically in the right range for success. You’re going to store the excess carbs as glycogen and you’ll be able to perform better, longer. It’s just kind of a good match-up given the macronutrient needs,” she said.
Levin described our society as “carb-phobic.” She likes to remind people that fiber is a carbohydrate and is completely lacking in our diets. You can only get fiber from plants, she said, and how are you going to get the 40 mg of fiber you need per day without eating carbs?
“You just want to choose wisely. You don’t want your carbs to come from Twizzlers. You want your carbs to come from fruits and vegetables and bean and grains,” Levin said. (“No offense to Twizzlers! I guess I should say ‘candy.’”)
“The only thing that anyone needs to think about on a plant-based diet that’s not going to be naturally occurring in the diet is B-12,” Levin said. “That doesn’t have anything to do with being an athlete.”
Vitamin B-12 is made by bacteria and you can only get it out of another animal’s body or out of the ground. Since our food sources are typically too clean to contain B-12, she said the standard recommendation is supplementing with 1,000 mcg three times a week.
Another Great Reason to Go Plant-Based!
Until now there’s been three core reasons for going vegan, Levin said – ethical vegans, environmental vegans, and healthy vegans. Now there’s a fourth reason, athletic performance, a fourth leg on the “vegan table,” as she put it.
More and more professional athletes are adopting a vegan diet and winning, she said – and it’s working!
“I’m a big fan of anything that gets people eating better because I come from the health side of things,” she said.
“What you‘re going to find is that this way of eating is going to make you feel amazing. It’s going to be your best option for preventing the things that kill us like diabetes, heart disease, and cancer. Prevention being key, but even if you’re already there, if you already have heart disease or cancer or diabetes, this is going to help you,” she said.
“It’s never too late.”