Somewhere on the internet right now, someone is very confidently telling you that you cannot build muscle without meat. Somewhere else, someone is very confidently telling you that meat is destroying your athletic performance. Both people are wrong, but only one of them will be interrupted by science today.

A new randomized trial gave 36 college athletes a chance to test both sides. For four weeks they ate like omnivores, hitting animal protein at least twice a day. For another four weeks they went mostly plant-based, swapping meat for beans, tofu, and plant-based meat alternatives. Then researchers checked how far they could run and how much they could lift.

The result? Almost no difference. Runners covered about 8,720 feet on the meat-based diet and 8,602 feet on the plant-based one, which works out to a gap of about 36 meters over 12 minutes. That is roughly the length of a bowling lane. Not exactly dramatic. Strength scores were about 4 percent lower on the plant-based diet, but even that difference did not clear the statistical bar for significance.

Cue the headlines: "Plants Fuel Athletes Just as Well as Meat!"

Not so fast. The real story is more interesting, and it comes with a few important asterisks that never make it into the tweet.

What the Study Actually Did

Researchers from Rutgers, Stanford, Vanderbilt, and the University of Reading recruited 36 undergraduates who exercised three or four times a week. Sixteen were recreational runners. Twenty were resistance trainers who lifted weights. Every participant did both diets, in random order, using campus dining halls to eat their assigned meals. This is called a crossover design and it is a good one, because each person acts as their own comparison. You do not have to worry about one group being genetically luckier or naturally more athletic. Everyone gets tested against themselves.

The runners were measured with a 12-minute maximum-distance test. The lifters were measured on chest press, lat pulldown, and leg press using three-rep maxes. Simple, standardized, easy to compare.

Then the researchers looked at the numbers, saw no significant differences, and reported the news.

The Sneaky Difference Between "No Difference" and "The Same"

Here is a phrase every science reader should tuck into their back pocket. Absence of evidence is not evidence of absence.

When a study says "we found no significant difference," it does not automatically mean "the two things are identical." It might mean the study was too small to catch a real difference that actually exists. This trial had 36 people total, split between running and lifting. That is a small pool. To officially prove that two things are equivalent, researchers use a specific study design called a non-inferiority or equivalence trial. This was not one of those.

The strength result shows why this matters. Lifters were 4 percent weaker on the plant-based diet, with a p-value of 0.08. In science, the traditional cutoff for "this is probably real" is 0.05, so 0.08 is close but not close enough. The confidence interval (which shows the range of plausible true effects) ran from a 8.5 percent decrease all the way to a 0.6 percent increase. Translation: the actual truth might be that plant-based eating causes a meaningful strength dip in these conditions, and a bigger study could catch it. Or it might not. We honestly cannot tell yet.

The most accurate summary is this: over four weeks, no clear performance difference showed up. That is genuinely useful. It is not the same as saying "the diets are proven equal."

About Those Food Diaries

There is a second wrinkle that anyone who has ever tried to log food will recognize. When people write down what they eat, they usually get it wrong. Almost always in the same direction. They forget snacks. They round down. They somehow don't remember the handful of chips.

In this study, participants logged their food only about three days per week and reported eating dramatically less protein during the plant phase (about 71 grams a day) compared to the omnivore phase (about 103 grams a day). Total calories also came out surprisingly low, which is often a sign that people are underreporting how much they actually ate.

Why does this matter? Because if we are not sure what people actually ate, we cannot be sure what the numbers really mean. The protein comparison in particular is on shaky ground. And 71 grams of protein per day is on the low side for someone actively lifting weights.

Was There Enough Protein to Actually Build Muscle?

Here is where sports nutrition gets specific. For an average 155-pound (70 kg) adult who lifts weights, that reported plant-based intake works out to about 1.0 gram of protein per kilogram of body weight per day. The American College of Sports Medicine, which sets the mainstream guidelines, recommends 1.2 to 2.0 grams per kilogram for active people. Research specifically on plant-based lifters points to about 1.6 grams per kilogram as the sweet spot for building muscle.

So the plant-based phase in this study delivered less protein than what sports scientists generally recommend for people who are trying to get stronger. That is not a fatal flaw for the study, but it does complicate the interpretation. The mild strength dip might not be about plants versus meat at all. It might be about total protein being too low.

An earlier trial called SWAP-MEAT Athlete (yes, that is the real name) made sure plant-based athletes hit their protein targets and found no strength difference between diets. Comparing the two studies suggests that plant-based eating works fine for lifters, as long as they actually eat enough of the right stuff.

What the Bigger Body of Research Says

Zoom out from this one study and the science is actually pretty encouraging for plant-based athletes.

A very cool study using deuterium-oxide tracers (basically labeled water molecules that let scientists watch protein get built into muscle in real time) found that vegan and omnivore diets support the same rate of muscle building when protein is matched. Another study compared 12 weeks of resistance training in vegans versus omnivores, with both groups getting 1.6 grams of protein per kilogram. Muscle gains, thigh muscle size, and leg-press strength were statistically identical.

For endurance athletes, plant-based diets might even offer a slight edge. A pooled analysis of multiple studies found a small positive effect on aerobic performance and no downside for strength or power.

The pattern is consistent. When plant-based athletes hit their protein numbers, they perform just as well as their meat-eating counterparts. When they don't, they can lag a bit.

The Catch: Not All Protein Is Interchangeable

Here is the honest counterpoint that fair coverage should include. A 2025 review of 43 randomized trials found that when researchers compared plant proteins directly to animal proteins for building muscle mass, animal protein came out slightly ahead. The gap was driven mostly by non-soy plant proteins like rice, oat, chia, and potato. Soy protein performed about the same as animal protein. Strength and general athletic performance showed no clear difference between plant and animal sources.

Why the small edge for animal protein? Two main reasons. First, digestibility. Your body actually absorbs and uses more of the protein in a steak than in a bowl of oatmeal, gram for gram. Second, amino acid content. Muscle building depends on getting enough of an amino acid called leucine, which acts like the ignition switch for muscle growth. Most plant proteins have less leucine than animal proteins.

None of this means plant proteins don't work. They absolutely do. It means plant-based athletes may need to eat somewhat more total protein, lean on higher-quality plant sources like soy, tempeh, and pea protein, or mix plant proteins together to get a complete amino acid profile. It is not that hard. It just takes a little more thought than throwing chicken on the grill.

The Micronutrient Story That Barely Gets Told

Protein grabs the headlines, but plant-based athletes need to pay attention to a handful of other nutrients that vegetarians and vegans commonly run low on.

Vitamin B12 is the big one. It essentially does not exist in plant foods (in usable form) so anyone eating strict vegan needs to supplement or eat fortified foods. Without B12, you get fatigue, nerve problems, and eventually anemia. Iron is another common shortfall. The type in plants (non-heme iron) is less easily absorbed than the type in meat (heme iron), especially for female athletes who lose iron with menstruation. Zinc, calcium, vitamin D, and omega-3 fatty acids also deserve attention. Plant-based athletes may also have lower stores of creatine and carnosine, both of which are found mostly in meat.

The good news is that all of this can be handled. Fortified foods, thoughtful meal planning, and occasional blood work to check iron status will get most people where they need to be. But the four-week phases in this study were too short to reveal any of these longer-term issues.

What This Study Is Good For, and What It Isn't

The trial has real strengths. The crossover design is smart. Using dining halls means people actually ate meals in a real-world setting, not carefully weighed portions in a lab. The runners and lifters were representative of many recreational athletes.

But the trial cannot tell us how plant-based eating affects performance over months or years. It cannot tell us about elite athletes with much higher training loads. It cannot tell us whether muscle would eventually accumulate at different rates. And the self-reported food logs weaken confidence in the mechanistic details.

The Bottom Line

For a recreational athlete curious about eating more plants, the study is genuinely reassuring. Over a month of plant-based eating, runners still ran about the same distance and lifters still lifted about the same weight. The dramatic performance loss that internet warriors keep predicting simply did not show up.

But the more honest, useful version of the message is conditional. Plant-based diets can support athletic performance if you actually hit your protein target (around 1.6 grams per kilogram of body weight if you lift weights), if you choose higher-quality plant proteins or use blends, and if you take care of B12, iron, and vitamin D.

Do all that, and there is no strong evidence that eating plants will hold you back. Skip those things, and you might notice your strength trending downward, your energy dipping, or your recovery slowing over time.

The bigger truth is that "plants versus meat" is the wrong framing anyway. Total nutrition matters more than the source of your protein. Whether your leucine comes from tofu, whey, chicken, or a mix of all three, your muscles do not really care about the origin story. They care about whether they got what they need to rebuild.

So if you want to eat more beans, go for it. Your muscles can work with that. Just make sure the beans actually show up, in adequate amounts, alongside the other nutrients that plant-based eating tends to under-deliver. Do that and your training will keep moving forward.

And if anyone on the internet tells you that a plant-based athlete cannot exist, ask them to explain that to the various vegan strongmen, ultramarathoners, and Olympians currently outperforming most of us. Then feed them a chickpea. Politely.

Raygoza, C., Roberts, A., Guidetti, A., Cai, O., Sangowdar, P., Muriuki, E. N., Laverick-Johnson, H., Sanguinetti, G., Smith, E., Fammartino, A., Robinson, J., Lee, E., Policastro, P., Mills, C., Kuhnle, G., Svennevik, E., & Gardner, C. (2026). Plant-based vs. omnivore diets for athletic performance outcomes among recreational athletes in university dining halls: A randomized crossover study. Nutrition Journal, 25(1), 42. https://doi.org/10.1186/s12937-026-01290-1