The purpose of this study is to assess whether the greater performance benefits from ingesting carbohydrate-protein supplements during endurance running, in comparison to the traditionally used carbohydrate supplement, is attributed to the extra calories contained in the carbohydrate-protein supplement or the presence of protein.

The purpose of this study is to determine whether the performance benefits from consuming a carbohydrate-protein (CHO-P) supplement, such as Accelerade, during endurance exercise, as opposed to the traditionally used carbohydrate (CHO) supplement, such as Gatorade, are attributed to the extra calories in the CHO-P supplement or the presence of protein alone in comparison to CHO supplements. Numerous studies comparing CHO and CHO-P supplements on endurance performance have found contradicting results in terms of CHO-P supplementation and performance benefits. While physiological mechanisms have been proposed as to why the CHO-P supplements elicit greater performance, research has yet to determine why some studies have found this, especially while other studies have found no performance benefits from CHO-P supplementation. This inconsistency in research may be due to the caloric difference between supplements tested; due to the addition of protein, the CHO-P supplement contains more calories per serving than the CHO supplement. As a result, this study will be comparing 4 different supplements during endurance exercise, a CHO-P supplement, CHO supplement, a double carbohydrate supplement (CHO-CHO), and a placebo (PLA). The CHO and CHO-P supplement will be matched for CHO content, whereas the CHO-P and CHO-CHO supplements will be matched for total caloric content. Participants will be asked to run four 12-mile runs on 4 separate occasions, approximately 7-10 days apart, and will be blinded to supplement content and order of supplement administration among trials. The 12-mile run will elicit an exercise bout greater than 60 minutes, which is relevant when supplementing exercise with CHO or CHO-P. Performance will be assessed via time it takes to complete both the 12-mile run and the 1.6 mile maximal effort at the end of the run.

Inclusion Criteria:

• Males aged 18-55 years old
• BMI in the healthy range, 18.5-24.9
• Run 45-90+ minutes at least 4 days per week
• Engage in running this frequency and duration for at least 4 weeks prior to the phone screen
• Engage in a run consisting ≥10 miles in length for at least 2-4 occasions per month for at least 2 months prior to the phone screen
• No previous history of heart conditions
• No shortness of breath or chest pain experienced during running or daily activities
• No bone or joint problems experienced during running or daily activities

Exclusion Criteria:

• Females and males under the age of 18 and over the age of 55
• Females are excluded from this study in order to prevent any potential factors associated with the female athlete triad and endurance performance outcomes.
• BMI below 18.5 or greater than 24.9
• Does not meet all other criteria listed (#3-6)
• Allergies to products containing milk, soy, or aspartame
• Severe allergies to eggs, wheat, tree nuts, fish, crustaceans, shellfish products (Accelerade, the CHO-P supplement, is made in a facility that processed these products)
• Refusal to consume any of the supplements, and/or extreme dislike of the supplements
• Refusal to complete the specified distance of the time trials