| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool L3 2ET; 2 University Department of Anaesthesia, University Hospitals of South Manchester, Withington Hospital, Manchester M20 2LR; and 3 Oxford Lipid Metabolism Group, Radcliffe Infirmary, Oxford OX2 6HE, United Kingdom
The physiological and metabolic demands of hill walking have not been studied systematically in the field despite the potentially deleterious physiological consequences of activity sustained over an entire day. On separate occasions, 13 subjects completed a self-paced hill walk over 12 km, consisting of a range of gradients and terrain typical of a mountainous walk. During the hill walk, continuous measurements of rectal (Tre) and skin (Tsk) temperatures and of respiratory gas exchange were made to calculate the total energy expenditure. Blood samples, for the analysis of metabolites and hormones, were taken before breakfast and lunch and immediately after the hill walk. During the first 5 km of the walk (100- to 902-m elevation), Tre increased (36.9 ± 0.2 to 38.5 ± 0.4°C) with a subsequent decrease in mean Tsk from this time point. Tre decreased by ~1.0°C during a 30-min stop for lunch, and it continued to decrease a further 0.5°C after walking recommenced. The total energy intake from both breakfast and lunch [5.6 ± 0.7 (SE) MJ] was lower than the energy expended [14.5 ± 0.5 (SE) MJ; P < 0.001] during the 12-km hill walk. Despite the difference in energy intake and expenditure, blood glucose concentration was maintained. The major source of energy was an enhanced fat oxidation, probably from adipose tissue lipolysis reflected in high plasma nonesterified fatty acid concentrations. The major observations were the varying thermoregulatory responses and the negative energy balance incurred during the hill walk. It is concluded that recreational hill walking can constitute a significant metabolic and thermoregulatory strain on participants.
energy balance; thermal regulation; field study
This article has been cited by other articles:
|
|
 |
|
  R. W Hoyt, P. K. Opstad, A.-H. Haugen, J. P DeLany, A. Cymerman, and K. E Friedl Negative energy balance in male and female rangers: effects of 7 d of sustained exercise and food deprivation Am. J. Clinical Nutrition, May 1, 2006; 83(5): 1068 - 1075. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P N Ainslie and T Reilly Physiology of accidental hypothermia in the mountains: a forgotten story Br. J. Sports Med., December 1, 2003; 37(6): 548 - 550. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. N. Ainslie, I. T. Campbell, K. N. Frayn, S. M. Humphreys, D. P. M. MacLaren, and T. Reilly Physiological, metabolic, and performance implications of a prolonged hill walk: influence of energy intake J Appl Physiol, March 1, 2003; 94(3): 1075 - 1083. [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]
|
|
|
|
|
|
P. N. Ainslie, K. Abbas, I. T. Campbell, K. N. Frayn, M. Harvie, M. A. Keegan, D. P. M. MacLaren, I. A. Macdonald, K. Paramesh, and T. Reilly Metabolic and appetite responses to prolonged walking under three isoenergetic diets J Appl Physiol, May 1, 2002; 92(5): 2061 - 2070. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
