Running on a treadmill for 90 minutes at 70% of your capacity is going to generate a hormonal response. How can you elevate that response after a second 90 minute run at the same intensity? A study published in theInternational Journal of Sport Nutrition and Exercise Metabolism suggests consuming a carbohydrate-rich beverage containing whey protein isolates.

Researchers had some subjects consume a drink containing 0.8 grams of sucrose and 0.3 grams of whey protein isolates per kg of body weight (52.8 grams of carbs and 19.8 grams of protein for a 145 pound person) during a 4-hour rest period between time trials. Others got a drink containing either 0.8 grams or 1.1 grams of carbs per kg of body weight (52.8 grams or 72.6 grams of sucrose for that same 145 pound person). The protein containing drink elevated levels of growth hormone and testosterone while suppressing the catabolic hormone cortisol.

True Strength Moment: Muscle mass is important to all types of athletes, not just bodybuilders and power lifters. Whey protein isolates are a rich source of essential amino acids including the branched chain amino acids known to play a significant role in muscle building. If this pure form of whey protein can help trigger natural anabolic hormones, it might help put more spring in your step for the next endurance run.