 What effect, if any, does a vegetarian or plant-based diet have on an athletic performance? Watch the video to find out. Recently, the remains of dozens of Roman gladiators were discovered in a mass grave. The clout of their identities were the rather distinct types of mortal injuries they found, like being speared in the head with a trident. Using just their skeletons, they were able to reconstruct the death blows, show just how buff they really were, and even try to reconstruct their diet of barley and beans. You can look at carbon isotopes and see what kind of plants they ate. Nitrogen isotopes reflect any intake of animal protein, and you can look at the sulfur in their bones and the amount of strontium, leading commentators to submit that the best athletes in ancient Rome ate largely plant-based diets. Then there were the legionnaires, the Roman army troopers, famed for their abilities, also eating a similar kind of diet, suggesting the best fighters in the ancient world were essentially vegetarian. So if the so-called perfect fighting machines, the great sports heroes of the day, were eating mostly grains and beans, should that tell us anything about sports nutrition and the preferred diets of elite athletes? Well, most of the Greeks and Romans were basically vegetarian and centering their diets around grains, fruit, vegetables, and beans, so maybe the gladiators diets weren't that remarkable. Plato, for example, pushed plants, preferring plant foods for their health and efficiency. So yes, the Roman gladiators were known as the barley men, but is that because barley gives you strength and stamina, or was that just the basic food that people ate at the time, not necessarily for performance, but because it was just so cheap? Well, if you look at the modern Spartans, the Tarhumar Indians, the ones that run races where they kick a ball for 75 miles just for the fun of it, running all day, all night, and all day maybe 150 miles of their feeling in the mood, what do you get if you win? A special popularity with the ladies, although how much of a reward that would actually prove to be for a man that had just been running for two days straight is questionable, though maybe their endurance extends to other dimensions. Probably not since the days of the ancient Spartans, as a people achieved such a high state of extreme physical conditioning, and what did they eat? The same kind of 75 to 80% starch diet based on beans, corns, and squash. And they had the cholesterol levels to prove it. Total cholesterol levels down at essentially in heart attack proof 136, and it's not just some special genetics they have, you feed them enough egg yolks and their cholesterol creeps right up. Modern-day Olympian runners eat the same stuff. What are they eating over there in Kenya? A 99% vegetarian diet centered mostly around various starches. But as in all these cases, is there remarkable physical prowess because of their diets, or in spite of their diets, or have nothing to do with their diets? You don't know until you put it to the test. In spite of well-documented health benefits for more plant-based diets, less is known regarding the effects of these diets on athletic performance. So they compared elite vegetarian and omnivore endurance athletes for aerobic fitness and strength, so comparing oxygen utilization on the treadmill and quad strength with leg extensions, and the vegetarians beat out their omnivore counterparts for cardiorespiratory fitness, but their strength didn't differ, suggesting in the very least that vegetarian diets don't compromise athletic performance. But this was a cross-sectional study. Maybe the veg athletes were just fitter because they trained harder? Like in the National Runners Health Study, looking at thousands of runners, vegetarian runners were recorded running significantly more on a weekly basis. So maybe that explains their superior fitness, though maybe their superior fitness explains their greater distances. Other cross-sectional studies have found no differences in physical fitness between vegetarian and non-vegetarian athletes, or even worse, performance, as in this study of vegetarian athletes in India. Of course, there could be socioeconomic or other confounding factors. That's why we need interventional studies to put different diets to the test and then compare physical performance, which we'll explore next. In 1896, the aptly named James Parsley evidently led a successful vegetarian cycling club to victory, their competitors evidently having to eat crow with their beef. Evidently, some Belgian put it to the test in 1904, with those eating more plant-based, supposedly lifting some weight, like 80% more times, but I couldn't find that primary source in English. This I could find, though a famous series of experiments at Yale published more than a century ago on the influence of flesh eating on endurance. 49 people were compared, regular athletes, mostly Yale students, vegetarian athletes, and then just sedentary vegetarians. The experiment furnished a severe test of the claims of those flesh abstainers. Much to the researcher's surprise, the results seem to vindicate the vegetarians, suggesting that not eating meat leads to far greater endurance compared to those accustomed to the ordinary American diet. Check it out. The first endurance test was how many minutes straight you could hold out your arms horizontally, flesh eaters versus flesh abstainers. The regular Yale athletes were able to keep their hands out for about 10 minutes on average. It's harder than it sounds. Give it a try. Okay, but those eating vegetarian did like five times better. The meat eater maximum was only half that of the vegetarian average. Only two meat eaters even hit 15 minutes, whereas more than two-thirds of the meat avoiders did. None of the regular diet folks hit a half an hour, whereas nearly half of the healthier eaters did, including nine that exceeded an hour, four that exceeded two hours, and one guy going for more than three hours. How many deep knee bends can you do? One athlete could do more than 1,000, averaging 383, but they got creamed even by the sedentary plant eaters. That's the crazy thing. Even the sedentary abstainers surpassed the exercising flesh eaters. The sedentary abstainers were in most cases physicians who sat on their butts all day. I want a doctor that can do 1,000 deep knee bends. And then in terms of recovery, all those deep knee bends left everyone sore, but more so among those eating meat. Among the vegetarians of two that did like 2,000 knee bends, one went straight off to the track to run, and another went on to their nursing duties. On the other hand, among the meat eaters, one guy reached 254, went down once more, and couldn't get back up, had to be carried away, and was incapacitated for days. Another impaired for weeks after fainting. It may be inferred without reasonable doubt, concluded the once skeptical Yale researcher that the meat eating group of athletes was very far inferior in endurance to the vegetarians, even the sedentary ones. What could account for this remarkable difference? Some claimed that flesh foods contained some kind of fatigue poisons, but one German researcher who detailed his own experiments with athletes offered a more prosaic answer. In his book on what looks like physiological studies of uber-driving vegetarians, I told you I only know English, he conjectured that the apparent vegetarian superiority was just due to their tremendous determination to prove their point and spread their propaganda. So they just make a greater effort in any contest than do their meat eating rivals. The Yale researchers were worried about this, so special pains were taken to stimulate the flesh eaters to the utmost, appealing to their college pride. Don't let those lousy vegetarians beat the Yale spirit. The experiments made it into the New York Times. Yale's flesh eating athletes, sounds like a zombie movie, beaten in severe endurance tests. Yale professor believes that he has shown definitely the inferiority and strength and endurance tests of meat eaters compared to those who do not eat meat. Some of Yale's most successful athletes took part in the strength test, and Professor Fischer declares they were obliged to admit their inferiority. How has the truth of this result been so long obscured? One reason Professor Fischer suggested is that vegetarians are their own worst enemy. In their fanaticism, they jump from the premise that meat eating is wrong, often based on scripture or some kind of dogma, and jump from that to meat eating is unhealthy. That's not how science works, and such logical leaps gets them dismissed as zealots and prevents any genuine scientific investigation. Lots of science even back then was pointing a distinct trend towards more plant-based eating, and yet the word vegetarian even 110 years ago had such a bad preachy rap that many were loathe to concede the science in its favor. The proper scientific attitude is to study the question of meat eating in precisely the same manner as one would study the question of anything else.