Can You Drink a Protein Shake Before Doing Cardio?

Fitness professionals recommend protein drinks, primarily after exercise, to replenish and repair the body after working out. But drinking a protein shake before exercise can provide needed energy and reduce the impact exercise has on your body. If your goal is to build muscle, a protein shake before a workout is equally as effective in stimulating muscle protein synthesis as having one after your workout.

Exercise Impact on Body

Exercise is crucial to health. It builds strength, controls weight and helps keep your heart and lungs working efficiently. But exercise also strains the body. You lose liquid and electrolytes through sweat, which can lead to dehydration. Exercise uses your energy stores to fuel the workout, which can leave you feeling tired and sluggish. It also breaks down muscle tissue, something you may feel the next day as muscle soreness.

Hydration

You probably drink water or sports drinks during and after a cardio workout, but having fluid from a protein shake before exercising can keep you hydrated during your workout. A position paper by the American College of Sports Medicine reports that inadequate hydration before exercise can impair your body's ability to dissipate body heat, increase core body temperature and lead to greater cardiovascular strain. The paper recommends drinking 17 ounces of fluids before your workout.

Energy

Your body converts carbohydrates to glucose, which it then uses for energy. During exercise, your need for energy increases. If you haven't eaten or your body isn't properly fueled, you will feel sluggish or lightheaded during your workout. Protein shakes have carbohydrates your body can use to fuel the exercise. Protein shakes are small enough that you can drink them an hour before your cardio workout and have the energy you need.

Protein

Your body doesn't use protein to fuel your cardio, but it needs protein to build and repair muscles. Exercise professionals recommend protein shakes following a workout to stimulate the repair of damaged muscle tissue. However, a study published in the January 2007 issue of the "American Journal of Physiology, Endocrinology and Metabolism" reported that a pre-exercise protein shake stimulated amino acid uptake as effectively as a postworkout protein shake. Amino acids are the components from which proteins and muscles are made.