A medium banana and two tablespoons of peanut butter combined have 611 milligrams of potassium, which is a great electrolyte that prevents cramping during hard workouts. What’s also great about this combo is that it’s relatively low in sodium — just 153 milligrams. More than likely, you probably already get enough sodium in your diet, anyway. Peanut butter and banana together also have 89 milligrams of magnesium, which is another electrolyte athletes need to maintain fluid balance and sustain muscular contractions.
Active athletes need vitamin B6 to break down protein so it can build and repair muscles and other tissues. Eating banana and peanut butter together puts you one-third on your way to your daily recommended amount of vitamin B6. You’ll also get 31% of your daily niacin to help metabolize food into energy. Amino acids such as arginine are also key for athletes and working out. A 2017 study in the European Journal of Clinical Nutrition found that athletes who supplemented their diets with 2 grams of L-arginine per day for 45 days saw greater improvements in their VO2 max, a measure of sports performance. Peanut butter and banana together have 933 milligrams of arginine.