Carbohydrate or Protein Drinks Before Exercise in the Heat

The Impact of Pre-Exercise Meal Composition on Metabolic Heat Production and Thermal Strain During Exercise in a Hot Environment

This project examines whether consuming a high-protein or high-carbohydrate beverage before exercise in the heat impacts metabolism and heat balance during exercise, with the following research questions:

1. Does a high-protein vs. high-carbohydrate pre-exercise drink impact metabolism and body temperature responses during a treadmill walking in the heat?
2. Does a high-protein or high-carbohydrate drink change oxygen use and heat production during treadmill walking in the heat?

Study Overview

• Status: Not yet recruiting
• Conditions: Heat Stress; Diet Induced Thermogenesis; Protein Consumption
• Intervention / Treatment: Dietary supplement: Protein shake; Dietary supplement: Carbohydrate shake

• Study Type: Interventional
• Enrollment (Estimated): 16
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Brett R Ely, PhD; Phone Number: 401-865-2632; Email: bely@providence.edu
• Study Contact Backup: Name: Margaret Morrissey-Basler, PhD; Phone Number: 401-865-1209; Email: mmorri17@providence.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Able to walk or run up to 5 mph on a treadmill
• Able to consume products containing dairy (no allergy or dietary restrictions)

Exclusion Criteria:

• Following a diet that excludes any macronutrient group (low-carb or low-fat)
• Diagnosed cardiovascular or metabolic diseases (hypertension, diabetes)
• Diagnosed heat illness in past 3 months (heat exhaustion, heat stroke)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: High Protein; A 22-oz high-protein, low-carbohydrate shake (chocolate flavor), given 60-90 minutes before exercise.	Dietary supplement: Protein shake; 22 oz of a beverage containing 320 kilocalories (60g protein, 6g fat, 8g carbohydrate).
Active Comparator: High Carbohydrate; A 22-oz, high-carbohydrate, low-protein & fat shake (chocolate flavor), given 60-90 minutes before exercise	Dietary supplement: Carbohydrate shake; 22oz of a carbohydrate drink containing 320 kilocalories (75g carbohydrate, 3g protein, <1g fat)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Metabolic Heat Production	Heat production measured during exercise at 6 watts/kg, calculated based on oxygen consumption and carbon dioxide production during exercise (indirect calorimetry)	Measured during 60 minutes of steady state exercise in 36C, 40% humidity

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Core Temperature	Internal temperature change during exercise	Measured at rest and following 60 minutes of exercise in a warm (36C, 40% humidity) environment
Urinary NGAL (ng/mL)	Measured after exercise in high-protein and high-carbohydrate trials, NGAL (neutrophil-gelatinase associated lipocalin; a marker of acute kidney injury) will be measured in urine samples in each trial to assess kidney function.	Following 60 minutes of exercise in a warm environment (36C, 40% relative humidity)
Urine Specific Gravity (USG)	Measured in urine samples provided before and after exercise, USG will be used as a marker of urine concentration and hydration status with each intervention.	Measured before and after 60 minutes of exercise in a warm (36C, 40%RH) environment.
Proteinuria	Measured after exercise in high-protein and high-carbohydrate trials, total protein content will be measured in urine samples in each trial to assess kidney function.	Following 60 minutes of exercise in a warm environment (36C, 40% relative humidity)

Collaborators and Investigators

• Sponsor: Providence College

Study record dates

Study Major Dates

• Study Start (Estimated): June 4, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): May 1, 2027

Study Registration Dates

• First Submitted: June 2, 2026
• First Submitted That Met QC Criteria: June 10, 2026
• First Posted (Actual): June 15, 2026

Study Record Updates

• Last Update Posted (Actual): June 15, 2026
• Last Update Submitted That Met QC Criteria: June 10, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: high protein diet, exercise, hot environment
• Additional Relevant MeSH Terms: Wounds and Injuries; Behavior; Heat Stress Disorders; Motor Activity
• Other Study ID Numbers: FY26-66

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No