It’s no surprise: Eating plants is good for health. Multiple studies have demonstrated that following a vegetarian or vegan diet not only promotes healthy aging, but is also protective against certain chronic conditions like heart disease, diabetes, and cancer. [1-4] And there is an increasing sector of the population focused on simply reducing their consumption of animal foods. This shift towards a more plant-focused diet can specifically benefit amateur and elite athletes, as such an eating pattern can provide an increased intake of vitamins, minerals, antioxidants, and fiber and reduced consumption of saturated fat. Here’s the science behind why that’s the case and the steps you can take to succeed as a plant-based athlete.
How to eat a plant-based diet as an athlete
What plant-based athletes eat will depend on what foods they exclude from their diet. This will also change with an individual's preferences. There is no one way to eat plant-based. Some people may choose to go vegan, while others may want to include some fish or dairy. Meat isn't taboo on a plant-based diet, so red meat and poultry can still be consumed. This eating pattern just means that plant-foods are prioritized, and athletes can choose to have animal products occasionally or in smaller portions if preferred. Ensuring that athletes are meeting their energy needs is critical no matter what diet they follow. Specific macro- and micronutrients will change on an individual basis depending on goals, training status, sex, and age among other factors.
There are a few nutrients that have the potential to be lacking in plant-based diets. These include omega-3 fatty acids, vitamin D, vitamin B12, and iron. A common concern is a plant-based athlete’s ability to get enough protein from the diet, but surveys done in endurance athletes show that most athletes meet their protein needs.  Here are some of the best plant-based sources of these nutrients.
- Omega-3 fatty acids (in the form of alpha-linolenic acid): chia, hemp, and flax seeds, and walnuts
- Vitamin D: fortified non-dairy milk alternatives, mushrooms, and sunlight
- Vitamin B12: nutritional yeast, soy milk, and fortified cereals
- Iron: beans, leafy greens (with a squeeze of citrus), fortified cereals (get more tips for maximizing iron absorption here)
- Protein: lentils, chickpeas, edamame, tofu, tempeh
Benefits of plant-based diets for athletes
Plant-based diets have shown positive effects on immune system health, inflammation levels, antioxidant status, and a number of other cardiovascular disease risk factors, including blood pressure and cholesterol levels (read more about cholesterol in this blog). [6,7]
Athletes following a plant-based diet may experience:
Reduced oxidative stress
During exercise, muscles produce reactive oxygen species, or free radicals. When the production of free radicals is greater than the body’s ability to neutralize them with antioxidants, oxidative stress occurs. And high levels of oxidative stress can result in cellular damage (aging), increased blood lipid levels, muscle fatigue, and reduced performance and recovery.
When looking at antioxidant activity, research has shown that vegans and vegetarians have higher antioxidant activity than omnivores due to the higher intake of antioxidants and antioxidant enzyme production. 
Regular exercise is known to reduce chronic inflammation, which is associated with some chronic diseases.  But, exercise can also result in acute (short-term) inflammation. This is often experienced as delayed-onset muscle soreness, impaired or slow recovery post-workout, and decreased performance. Inflammation levels can be measured by looking at the blood biomarker hsCRP or CRP, and levels peak around 24 hours after exercise.  While this acute inflammation can’t be avoided altogether, it should be resolved in a timely manner.
Healthy fats, like monounsaturated and omega-3 fatty acids, commonly found in plant-foods have anti-inflammatory properties.  A meta-analysis of 19 studies found that over a two-year period of adhering to a vegan or vegetarian diet reduced CRP levels. 
Increased blood flow
Athletic performance is impacted by the circulation of blood, as it carries nutrients and oxygen to muscles and gets rid of waste created by their metabolic processes. The health of our arteries and blood can therefore impact the body’s ability to carry out these functions. If blood flow is impaired, performance will be, too.
Dietary nitrates increase blood flow and may have positive impacts on performance and recovery from exercise.  These nitrates are different from the sodium nitrite that is often added to processed meats like bacon—which the combination of high heat and protein can form harmful compounds when meats are cooked.  Dietary nitrates that are beneficial for health can be found in foods such as spinach and other dark leafy greens, zucchini, and beets (read more about drinking beetroot juice for performance here). 
Improved storage of carbohydrates
Carbohydrates, which are broken down into glucose in the body, are the main source of fuel for aerobic exercise, and many athletes fail to eat enough to support their active lifestyle. Glycogen is the body’s storage form of glucose. During exercise, the body will pull glucose, or energy, from these glycogen stores in the liver or muscles for fuel. Insufficient carbohydrate intake will result in diminished glycogen stores to pull from during physical activity. In a study of 116 endurance athletes, only 46% of those athletes were found to be eating enough carbohydrates for training 1-3 hours per day. 
Since plant-based diets are rich in complex carbohydrates like those from legumes, whole grains, and root vegetables, glycogen stores are often improved in plant-based athletes. 
Athletic performance outcomes and plant-based diets
Despite these potential positive impacts on the body, the current research on plant-based diets and performance specific outcomes or exercise capacity in athletic individuals remains limited and inconclusive. [6,7,14,15]
But that doesn’t mean plant-based diets aren’t beneficial. Both plant-based diets and exercise are associated with improvements in immune system health, inflammation levels, and cardiovascular health, and paired together, they can have a synergistic effect are positive outcomes for non-active and active individuals alike. [6,7] And when they’re paired together, they can have almost a synergistic effect.
Athletes, don't make these mistakes if you decide to go plant-based
- Relying on ultra-processed plant-based alternatives in place of whole food options: Just because a food is plant-based, doesn’t necessarily mean it’s healthy—although marketing tactics of plant-based "chicken " nuggets, burgers or other highly processed can give off that illusion. These foods can still be full of dyes, texturizers, and emulsifiers, and even though those additives are plant-based, little is known about the potential nutritional quality they may provide. So, these ultra-processed alternatives should not be over consumed. Aim to follow a whole-food plant-based diet instead, and save the soy burgers for an occasional convenient option.
- Taking unnecessary supplements: Plant-based diets do have the potential to be lacking certain nutrients. But don’t just assume you have a nutrient deficiency, and don't grab the supplement bottle without checking your blood levels first. Getting a blood test can help determine if you are meeting your nutrition needs or if you might need a boost.
- Adopting an all or nothing approach to your diet: Food is a personal choice and eating 100% plant-based might be the right choice for you. But, just because there are benefits to eating a plant-based diet doesn’t mean it is the only way to eat for health and performance. Incorporating some dairy, meat, poultry, fish, or eggs may suit your health and lifestyle better. Just don’t skimp on the fruits, vegetables, and whole grains.
Succeed as a plant-based athlete
Not sure you’re ready to go all-in on a plant-based diet? It is important to know that you can still see benefits by including more plant-forward eating. A meta-analysis by Neale et al. assessed dietary patterns and the impact on biomarkers of inflammation found that a diet rich in whole grains, fruits and vegetables with infrequent red meat consumption to be associated with reduced CRP levels.  Instead of focusing on taking out foods to follow a plant-based diet, think of this eating pattern as an opportunity to add more plant-forward foods and meals into your diet.
Testing with InsideTracker can give you food and supplement recommendations that honor your dietary preferences and help optimize your biomarkers. Interested in learning more? Here’s how athletes can use InsideTracker to get the edge on their performance and health goals.
- Plant-based eating can improve overall health and reduce chronic disease risk
- Athletes who eat plant-based need still need to have adequate energy intake
- A plant-based diet tends to be richer in carbohydrates, fiber, and antioxidants
- There is potential for certain nutrient deficiencies but this does not mean you should supplement for them without a blood test
- If eating ultra processed plant-based food items, do so in moderation
- Even a more plant-forward diet can positively impact health
Stevie Lyn Smith, MS, RDN, CSSD, CDNStevie Lyn is a Content Strategist and Team Nutritionist at InsideTracker. As a Registered Dietitian and Ironman triathlete, she enjoys combining her passions to help educate others on how to fuel for overall health and performance. When she’s not swimming, biking, or running with her dog, you’ll find her in the kitchen working on a new recipe to improve her biomarkers.