A vegetarian or vegan diet can be compared to an animal-based diet even in providing sufficient energy during those long days of work or workouts. Muscles that undergo endurance training mainly get their fuel from glycogen (a carbohydrate). Plants are the primary source of this nutrient. Glucose acquired from plants is used to keep the brain focussed during intense workouts, competitions, and long workdays. Energy from the fat of animals does not replenish the immediate requirements. It may lead to fatigue and a lack of motivation to continue the intense training session. Carbohydrates are among the most beneficial food sources for optimum energy for exercise and endurance sports.