 We all want to eat the kinds of foods that make us feel better and live longer, but there's so much conflicting information out there. So many nutrition opinions. Welcome to the Nutrition Facts podcast. I'm your host, Dr. Michael Greger. It's my job to give you the information you need to make the healthiest choices possible. Today we discover how plant-based diets improve the performance of athletes and non-athletes alike. In my video about comparing vegetarian and vegan athletic performance, endurance, and strength, I discussed a 2020 study that found that vegan athletes, even though they were significantly older, had significantly superior aerobic capacity and endurance, lasting 25% longer on a time-to-exhaustion cycling test. The question is why? One potential mechanism that could explain the greater level of endurance performance in vegans may be a higher amount of carbohydrate intake, which could lead to better endurance performance through higher muscle glycogen storage. Other potential mechanisms that may explain the better endurance performance in vegans could be due to the antioxidant and anti-inflammatory profiles of their diet. Maybe it's even their hearts. Yet another study showing superior VO2 max in vegan athletes, meaning superior aerobic capacity. This time they also did echocardiograms, looking at their hearts in real time using ultrasound, and the lower relative wall thickness and better main ventricle systolic and diastolic function in the vegans are most likely positive findings. Now, wait a second. Given the higher VO2 max reached by the vegan athletes, maybe they were just better trained than the non-vegan athletes, and that's why their hearts looked like they were working better. However, the weekly training frequency and running distance were similar in both groups, suggesting benefits even with the same amount of training. So it's important to educate healthcare professionals so they don't try to discourage a vegan diet. It may even want to consider telling folks implementing an exercise training program to give it a try. But you don't know if it has the same kind of effects in non-athletes until you put it to the test. A vegetarian versus conventional calorie-restricted diet, the effect on physical fitness in response to aerobic exercise in patients with type 2 diabetes. Diabetics randomized to the same calorie restriction, the same exercise, but just vegetarian versus non-vegetarian. They provided all the meals so they could ensure compliance and closely monitor the exercise. VO2 max increased by 12% in the vegetarian group significantly better than in the non-vegetarian group who didn't significantly improve at all. Maximal performance increased by 21% in the vegetarian group. Again, significantly better than the non-vegetarian group who didn't significantly improve at all. In other words, the results indicated that more plant-based diets led more effectively to improvement in physical fitness than less plant-based diets after the same aerobic exercise program. It seems that those eating vegetarian were able to better burn-off carbohydrates compared to non-vegetarians and had better insulin sensitivity, both markers of improved metabolic flexibility, meaning the ability to switch back and forth between burning sugar and fat. Besides physiological mechanisms, there may also be psychological factors. They observed reduced hunger and reduced feelings of depression in the vegetarian group, which may have given them a more positive attitude towards exercise. Here's the psychological data. Those randomized eat vegetarian had a greater improvement in quality of life and mood. They felt less constrained, meaning the calorie restriction didn't seem as burdensome. They had less disinhibition, meaning less tendency to binge and overeat, along with maybe less feelings of hunger. Not to mention the superior effects of a vegetarian diet on body weight, glycemic control, blood lipids, insulin sensitivity, and oxidative stress. Wait, better body weight? I thought they were given the same number of calories. Yes, both diets were isochloric, the same calories, yet just eating meat free led to significantly more weight loss, about 6 pounds more, more waste loss, a slimmer waste, lower cholesterol, of course, and less superficial fat, meaning the external jiggly fat, and most importantly, significantly more visceral fat loss, the most metabolically dangerous deep belly fat. Same calories, yet more loss of body fat and, not surprisingly, better control of their diabetes, all in addition to leading more effectively to improvements in physical fitness. Did you know that long-term plant-based eating may improve exercise capacity and endurance? Here's the story. Few studies have investigated the impact of a plant-based diet on athletic performance, but the majority of the studies that have been done show differences in endurance, performance, or strength. So while plant-based diets do not seem to provide advantages or disadvantages on exercise performance, what plant-based diets can do is reduce the risk of chronic disease. A point I made in my video why all athletes should eat plant-based diets, because surprisingly, endurance athletes may have more advanced atherosclerosis and more heart muscle damage compared with sedentary individuals, so it's even more important they eat healthy. But due to the favorable impact on health, it could be assumed that performance would also be influenced by plant-based diets. Let's take a closer look at the available evidence. This is the most commonly cited review. Studies connecting vegetarian diets to improved health are well established. However, the evidence for this phenomenon to be transferred to improve physical performance in athletes is less clear, finding no difference, at least acutely, between a vegetarian-based diet and an omnivorous diet in muscular power, muscular strength, short burst, or endurance performance. The intervention studies in this review, however, only lasted days or weeks, so being a vegetarian for four days may not tip the balance, or even a few months. But see, that's a considerable limitation. These are people who had been eating meats, you know, their whole lives, and subsequently adopted vegetarian diet only for the duration of the study, rather than comparing participants who have adhered to a vegetarian diet long-term. This study compared exercise capacity of vegan, vegetarian, and meat-eating recreational runners and found similar maximum power output among all three groups, suggesting there's no significant difference in maximum exercise capacity, though that's at the same training frequency, time, and distance. Perhaps plant-based diets might enhance recovery and allow such athletes to train longer and harder? A number of studies have come out since this review was published in 2016. Let's take a look at the update. Well, this study compared the cardiorespiratory fitness and peak torque strength differences between vegetarian and omnivore endurance athletes. Most of the vegetarians were actually vegans and most for at least two years, and results from this study indicate that vegetarian endurance athletes' cardiorespiratory fitness was greater than that for their omnivorous counterparts. They had greater VO2 max, meaning greater maximal oxygen uptake, aerobic capacity as measured on a progressive, graded maximal treadmill test to exhaustion, though peak torque, peak strength, based on leg extensions, didn't differ between diet groups. Bottom line, these days suggest that vegetarians do not compromise performance outcomes and may facilitate aerobic capacity in athletes. In this 2020 study, all the plant-based participants were eating vegan for an average of four years, so they were essentially comparing those one years versus those who ate meat for 25 years. But after four years eating plants, you might expect to see some sort of difference. Yet, no significant differences were noted for upper and lower body muscle strength like in the last new study. Both groups of athletes were comparable for total body weight lean body mass, though age was significantly higher in vegans compared with omnivores, so that put them at a little disadvantage. Yet still, there it is again, a significantly better aerobic capacity. Then they had them pedaled until exhaustion, and the vegan group lasted about 25% longer, 12 minutes as opposed to 9 minutes. Is that just because their aerobic capacity is so high? No. Even after controlling for VO2 max levels, there was still a significant endurance advantage in the vegans. The researchers conclude that in the very least a strictly plant-based diet doesn't seem to be detrimental to endurance and muscle strength, and endurance max would be better in vegans, contrary to popular belief. We would love it if you could share with us your stories about reinventing your health through evidence-based nutrition. Go to nutritionfacts.org slash testimonials which may be able to share it on social media to help inspire others. If you'd like to see any graphs, charts, graphics, images, or studies mentioned here, go to the Nutrition Facts Podcast landing page there you'll find all the detailed information and information you need, plus links to all the sources we cite for each of these topics. My last two books were How to Survive a Pandemic and My How Not to Diet Cookbook. Get ready this year for the launch of How Not to Age, and of course all the proceeds for the sales of all my books goes directly to charity. NutritionFacts.org is a nonprofit science-based public service. We can sign up for free daily updates on the latest new nutrition research with bite-sized videos and articles uploaded nearly every day. Everything on the website is free. There are no ads, no corporate sponsorships, no kickbacks. It's strictly non-commercial, not selling anything. I just put it up as a public service as a labor of love as a tribute to my grandmother, whose own life was saved with evidence-based nutrition.