Fluid Balance During Exercise in the Heat With Water, Flavored Placebo, or a Carbohydrate-electrolyte Beverage Intake (The APEX Study) (APEX)

The purpose of the APEX study is to determine whether carbohydrate-electrolyte beverage intake promotes fluid balance during exercise in the heat compared with water or placebo intake.

Study Overview

• Status: Completed
• Conditions: Dehydration
• Intervention / Treatment: Other: Exercise Intervention

Detailed Description

Exercise in the heat has large effects on cardiovascular strain, the ability to regulate core body temperature, and performance because of an increase in the reliance on body fluid distribution to the skin to maintain adequate sweat rates and heat dissipation. Carbohydrate-electrolyte beverage intake during exercise in the heat may improve fluid balance and subsequent physical performance.

The participants will be assigned each arm in a randomized, counterbalanced, cross-over fashion separated by at least 2 weeks. Participants will be placed in a heated environment for the duration of the exercise intervention.

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Louisiana
    • Baton Rouge, Louisiana, United States, 70808
      • Pennington Biomedical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Males aged 18-35 years
• Healthy (No uncontrolled disease)

Exclusion Criteria:

• No medications that influence fluid balance
• No uncontrolled disease

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Water; Electrolyte- and mineral-free water with exercise intervention	Other: Exercise Intervention; Exercise intervention trials will consist of a steady-state bout of exercise at ~70% VO2peak and a timed performance test on a cycle ergometer in a heated environment.
Placebo Comparator: Placebo; Calorie- and electrolyte-free, sweetened flavored water with exercise intervention	Other: Exercise Intervention; Exercise intervention trials will consist of a steady-state bout of exercise at ~70% VO2peak and a timed performance test on a cycle ergometer in a heated environment.
Experimental: Carbohydrate-electrolyte beverage; Commercially-available flavored beverage carbohydrate-electrolyte beverage with Exercise Intervention	Other: Exercise Intervention; Exercise intervention trials will consist of a steady-state bout of exercise at ~70% VO2peak and a timed performance test on a cycle ergometer in a heated environment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fluid Balance	Fluid balance will be determined by change in body weight during the 120 minutes steady-state exercise bout in the heat.	120 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of fluid uptake in the GI tract	Fluid uptake in the GI tract be assessed by D20 accumulation in the plasma.	30 minutes
Amount of carbohydrate oxidized	Carbohydrate oxidation rates will be assessed by indirect calorimetry.	120 minutes
Cardiovascular responses	Heart rate and blood pressure will be assessed during exercise.	120 minutes
Thermoregulatory responses	Body temperatures will be assessed during exercise.	120 minutes
Physical Performance	Performance during the timed exercise trial will be improved with carbohydrate-electrolyte beverage intake compared with water and placebo intake.	30 minutes

Collaborators and Investigators

• Sponsor: Pennington Biomedical Research Center
• Investigators: Principal Investigator: Timothy S Church, MD, MPH, PhD, Pennington Biomedical Research Center; Study Chair: Neil M Johannsen, PhD, Louisiana State University-Department of Kinesiology; Study Chair: Ronald B Monce, PA-c, Pennington Biomedical Research Center

Publications and helpful links

General Publications

• Latzka WA, Sawka MN, Montain SJ, Skrinar GS, Fielding RA, Matott RP, Pandolf KB. Hyperhydration: thermoregulatory effects during compensable exercise-heat stress. J Appl Physiol (1985). 1997 Sep;83(3):860-6. doi: 10.1152/jappl.1997.83.3.860.
• Latzka WA, Sawka MN, Montain SJ, Skrinar GS, Fielding RA, Matott RP, Pandolf KB. Hyperhydration: tolerance and cardiovascular effects during uncompensable exercise-heat stress. J Appl Physiol (1985). 1998 Jun;84(6):1858-64. doi: 10.1152/jappl.1998.84.6.1858.
• Armstrong LE, Costill DL, Fink WJ. Influence of diuretic-induced dehydration on competitive running performance. Med Sci Sports Exerc. 1985 Aug;17(4):456-61. doi: 10.1249/00005768-198508000-00009.
• Cheuvront SN, Carter R 3rd, Castellani JW, Sawka MN. Hypohydration impairs endurance exercise performance in temperate but not cold air. J Appl Physiol (1985). 2005 Nov;99(5):1972-6. doi: 10.1152/japplphysiol.00329.2005. Epub 2005 Jul 14.
• Greenleaf JE, Sargent F 2nd. Voluntary dehydration in man. J Appl Physiol. 1965 Jul;20(4):719-24. doi: 10.1152/jappl.1965.20.4.719. No abstract available.
• Hubbard RW, Sandick BL, Matthew WT, Francesconi RP, Sampson JB, Durkot MJ, Maller O, Engell DB. Voluntary dehydration and alliesthesia for water. J Appl Physiol Respir Environ Exerc Physiol. 1984 Sep;57(3):868-73. doi: 10.1152/jappl.1984.57.3.868.
• Hamilton MT, Gonzalez-Alonso J, Montain SJ, Coyle EF. Fluid replacement and glucose infusion during exercise prevent cardiovascular drift. J Appl Physiol (1985). 1991 Sep;71(3):871-7. doi: 10.1152/jappl.1991.71.3.871.
• Nose H, Mack GW, Shi XR, Nadel ER. Role of osmolality and plasma volume during rehydration in humans. J Appl Physiol (1985). 1988 Jul;65(1):325-31. doi: 10.1152/jappl.1988.65.1.325.
• Nose H, Mack GW, Shi XR, Nadel ER. Involvement of sodium retention hormones during rehydration in humans. J Appl Physiol (1985). 1988 Jul;65(1):332-6. doi: 10.1152/jappl.1988.65.1.332.
• Wilk B, Bar-Or O. Effect of drink flavor and NaCL on voluntary drinking and hydration in boys exercising in the heat. J Appl Physiol (1985). 1996 Apr;80(4):1112-7. doi: 10.1152/jappl.1996.80.4.1112.
• Rivera-Brown AM, Gutierrez R, Gutierrez JC, Frontera WR, Bar-Or O. Drink composition, voluntary drinking, and fluid balance in exercising, trained, heat-acclimatized boys. J Appl Physiol (1985). 1999 Jan;86(1):78-84. doi: 10.1152/jappl.1999.86.1.78.
• Wemple RD, Morocco TS, Mack GW. Influence of sodium replacement on fluid ingestion following exercise-induced dehydration. Int J Sport Nutr. 1997 Jun;7(2):104-16. doi: 10.1123/ijsn.7.2.104.
• Szlyk PC, Sils IV, Francesconi RP, Hubbard RW, Armstrong LE. Effects of water temperature and flavoring on voluntary dehydration in men. Physiol Behav. 1989 Mar;45(3):639-47. doi: 10.1016/0031-9384(89)90085-1.
• Vrijens DM, Rehrer NJ. Sodium-free fluid ingestion decreases plasma sodium during exercise in the heat. J Appl Physiol (1985). 1999 Jun;86(6):1847-51. doi: 10.1152/jappl.1999.86.6.1847.
• American College of Sports Medicine; Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 2007 Feb;39(2):377-90. doi: 10.1249/mss.0b013e31802ca597.
• Mitchell JW, Nadel ER, Stolwijk JA. Respiratory weight losses during exercise. J Appl Physiol. 1972 Apr;32(4):474-6. doi: 10.1152/jappl.1972.32.4.474. No abstract available.
• Brisson GR, Boisvert P, Peronnet F, Perrault H, Boisvert D, Lafond JS. A simple and disposable sweat collector. Eur J Appl Physiol Occup Physiol. 1991;63(3-4):269-72. doi: 10.1007/BF00233860. Erratum In: Eur J Appl Physiol 1993;66(6):552.
• Buono MJ, Jechort A, Marques R, Smith C, Welch J. Comparison of infrared versus contact thermometry for measuring skin temperature during exercise in the heat. Physiol Meas. 2007 Aug;28(8):855-9. doi: 10.1088/0967-3334/28/8/008. Epub 2007 Jul 6.
• Armstrong LE, Maresh CM, Gabaree CV, Hoffman JR, Kavouras SA, Kenefick RW, Castellani JW, Ahlquist LE. Thermal and circulatory responses during exercise: effects of hypohydration, dehydration, and water intake. J Appl Physiol (1985). 1997 Jun;82(6):2028-35. doi: 10.1152/jappl.1997.82.6.2028.
• Temesi J, Johnson NA, Raymond J, Burdon CA, O'Connor HT. Carbohydrate ingestion during endurance exercise improves performance in adults. J Nutr. 2011 May;141(5):890-7. doi: 10.3945/jn.110.137075. Epub 2011 Mar 16.
• Davis JM, Lamb DR, Burgess WA, Bartoli WP. Accumulation of deuterium oxide in body fluids after ingestion of D2O-labeled beverages. J Appl Physiol (1985). 1987 Nov;63(5):2060-6. doi: 10.1152/jappl.1987.63.5.2060.

Study record dates

Study Major Dates

• Study Start (Actual): October 1, 2012
• Primary Completion (Actual): October 1, 2013
• Study Completion (Actual): October 1, 2013

Study Registration Dates

• First Submitted: June 17, 2013
• First Submitted That Met QC Criteria: July 2, 2013
• First Posted (Estimate): July 9, 2013

Study Record Updates

• Last Update Posted (Actual): September 15, 2022
• Last Update Submitted That Met QC Criteria: September 13, 2022
• Last Verified: September 1, 2022

More Information

Terms related to this study

• Keywords: exercise; fluid balance; performance; body weight; heat; dehydration
• Additional Relevant MeSH Terms: Pathologic Processes; Metabolic Diseases; Water-Electrolyte Imbalance; Dehydration
• Other Study ID Numbers: PBRC 12038