A plant-based diet provides all of the nutrients your body needs for training and competition. Because a plant-based diet is high in carbohydrates, low in fat, and rich in vitamins, minerals, and antioxidants, it can support or improve your athletic performance. A Physicians Committee study published in the journal Nutrients found that plant-based athletes benefit from improvements in heart health, performance, and recovery. These are the word from The Physicians Committee on good nutrition for athletes.
The Physicians Committee is a nonprofit organisation, with a goal of dramatically changing the way doctors treat chronic diseases such as diabetes, heart disease, obesity, and cancer. By putting prevention over pills, doctors are empowering their patients to take control of their own health. The Physicians Committee combines knowledge & expertise from more than 17,000 physicians.
Carbohydrates: Carbohydrates are the primary fuel used during high-intensity exercise. Evidence shows that adding carbohydrates to your diet improves endurance and performance. On a per-calorie basis, carbohydrate needs for athletes are similar to those for anyone else. Specific recommendations for athletes are based on weight and activity type. If exercise is strenuous and repetitive, such as training for a marathon, then carbohydrate timing may be useful, e.g., carb loading pre-event and carb timing post-event. Otherwise, such strategizing with carbohydrate intake is unnecessary.
Protein: Compared with carbohydrates, protein is used only minimally for fuel. Its primary function is building and maintaining body tissue. Plant-based protein sources are best because, unlike animal sources, they contain fiber and complex carbohydrates. The recommended dietary allowance for the average, sedentary or lightly active adult is 0.8 grams per kilogram of body weight per day. For most people, this is more than enough. However, protein needs for athletes may range from 1.2 to 1.7 grams per kilogram of body weight per day.
Athletes looking for additional protein can get an extra boost from beans, nondairy milks, nuts, seeds, and soy products, including tofu, tempeh, and veggie burgers.
Fat: High-fat diets are not recommended for athletes. Animal products are high in saturated fat, which can lead to heart disease, diabetes, weight gain, and other chronic conditions.
https://www.pcrm.org/good-nutrition/nutrition-for-athletes