Journal of Applied Physiology, Vol 61, Issue 6 2162-2167, Copyright © 1986 by American Physiological Society

ARTICLES

Use of the doubly labeled water technique in humans during heavy sustained exercise

K. R. Westerterp, W. H. Saris, M. van Es and F. ten Hoor

We measured energy expenditure with the doubly labeled water technique during heavy sustained exercise in the Tour de France, a bicycle race lasting more than 3 wk. Four subjects were observed for consecutive intervals of 7, 8, and 7 days. Each interval started with an oral isotope dose to reach an excess isotope level of 200 ppm 18O and 130 ppm 2H. The biological half-lives of the isotopes were between 2.25 and 3.80 days. Energy expenditure was compared with simultaneous measurements of energy intake, and body mass and body composition did not change significantly. The doubly labeled water technique gave higher values for energy expenditure than the food record technique. The discrepancy showed a systematic increment from the first to the third interval, being 12.9 +/- 7.9, 21.4 +/- 9.8, and 35.3 +/- 4.4% of the energy expenditure calculated from dietary intake, respectively. Possible explanations for the discrepancy are discussed. The subjects reached an average daily metabolic rate of 3.4-3.9 or 4.3-5.3 times basal metabolic rate based on the food record technique and the doubly labeled water technique, respectively. Thus, when measured with the same technique, the energetic ceiling for performance in humans is comparable with that of animals like birds.

This article has been cited by other articles:

				M. den Hoed, M. K. C. Hesselink, G. P. J. van Kranenburg, and K. R. Westerterp Habitual physical activity in daily life correlates positively with markers for mitochondrial capacity J Appl Physiol, August 1, 2008; 105(2): 561 - 568. [Abstract] [Full Text] [PDF]

				P. N. Ainslie, I. T. Campbell, K. N. Frayn, S. M. Humphreys, D. P. M. MacLaren, T. Reilly, and K. R. Westerterp Energy balance, metabolism, hydration, and performance during strenuous hill walking: the effect of age J Appl Physiol, August 1, 2002; 93(2): 714 - 723. [Abstract] [Full Text] [PDF]

				K. R. Westerterp Limits to sustainable human metabolic rate J. Exp. Biol., March 11, 2002; 204(18): 3183 - 3187. [Abstract] [Full Text] [PDF]

				M. S. Johnson and J. R. Speakman Limits to sustained energy intake: V. Effect of cold-exposure during lactation in MUS MUSCULUS J. Exp. Biol., January 6, 2001; 204(11): 1967 - 1977. [Abstract] [Full Text] [PDF]

				R. D. Reynolds, J. A. Lickteig, P. A. Deuster, M. P. Howard, J. M. Conway, A. Pietersma, J. deStoppelaar, and P. Deurenberg Energy Metabolism Increases and Regional Body Fat Decreases While Regional Muscle Mass Is Spared in Humans Climbing Mt. Everest J. Nutr., July 1, 1999; 129(7): 1307 - 1314. [Abstract] [Full Text]

				D.-W. Gong, Y. He, M. Karas, and M. Reitman Uncoupling Protein-3 Is a Mediator of Thermogenesis Regulated by Thyroid Hormone, beta 3-Adrenergic Agonists, and Leptin J. Biol. Chem., September 26, 1997; 272(39): 24129 - 24132. [Abstract] [Full Text] [PDF]