If you feel a little sluggish before a workout session or need a treat to keep you fueled throughout your workout, this is an excellent nourishment option.Researchhas shown that consuming a banana pre-workout and even during a workout is as beneficial as a sports beverage. This is because bananas are rich in carbohydrates, which are the body's primary source of energy. The walnuts in this smoothie provide a satisfying dose of protein to fuel your muscles and keep you feeling full while providing a dose of omega 3, which aids brain and heart function.