Although high-protein supplements such as protein shakes and protein bars are often used by bodybuilders and strength-training athletes, these products can benefit other athletes, as well. Running is an intense physical activity, and consuming a protein bar after running may help enhance your recovery. Be sure to choose a bar with highly effective nutrients for optimal results. Consult a doctor before starting an exercise or supplementation program.
Protein provides your body with amino acids, the building blocks of muscle tissue. Supplying protein after exercise halts the process of muscle breakdown -- and if sufficient levels are consumed, protein can help spur muscle growth. Research from the December 2010 issue of the "International Journal of Sport Nutrition and Exercise Metabolism" suggests that consuming about 20 g of protein within the first few hours after your workout appears to maximize recovery. Many protein bars contain at least 20 g of protein, but if you find a protein bar with less protein than that, consuming it with an 8 oz. glass of skim milk, which provides 8 g of protein, can be effective for recovery.
Carbohydrates provide your body with fuel for exercise, so consuming a carbohydrate-rich protein bar after running may aid in recovery. Research from the May 2011 issue of, "The Journal of Strength and Conditioning Research" found that consumption of chocolate milk, a blend of carbohydrates and protein, was superior to carbohydrates alone for promoting recovery and performance in subsequent exercise sessions. Chocolate milk offers a carbohydrate/protein ratio of about 3:1, so a protein bar with a similar ratio may be good for post-running recovery.
Fat is a nutrient that helps you feel full, so it may be beneficial to consume a protein bar containing fat after your run if you are trying to control your food intake and lose weight. In addition, endurance sports such as running produce an increased rate of fat oxidation, so consuming a fat-rich protein bar after your run may be better than consuming it at a different time of day if you wish to reduce the likelihood that the dietary fat will be stored as body fat.
The calorie content of your protein bar is particularly important if you wish to gain or lose a significant amount of weight. If you want to lose weight, choose a protein bar that contains fewer calories than you burn during your run. For instance, if you jog at 5 mph for 30 minutes, you should consume a protein bar with fewer than 292 calories. If you wish to gain weight, choose a higher calorie protein bar. Note that the rest of your diet will also have an effect on your rate of weight gain or loss.