| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
ski1,ska1,1 Department of Sport Medicine, Academy of Physical Education, 61-871 Poznan; 2 Department of Applied Physiology, Medical Research Centre, Polish Academy of Sciences, 02-106 Warsaw, Poland; and 3 Laboratory for Human Environmental Physiology, National Aeronautics and Space Administration Ames Research Center, Moffett Field, California 94035-1000
To test the hypotheses that
short-term bed-rest (BR) deconditioning influences metabolic,
cardiorespiratory, and neurohormonal responses to exercise and that
these effects depend on the subjects' training status, 12 sedentary
men and 10 endurance- and 10 strength-trained athletes were submitted
to 3-day BR. Before and after BR they performed incremental
exercise test until volitional exhaustion. Respiratory gas exchange and
heart rate (HR) were recorded continuously, and stroke volume (SV) was
measured at submaximal loads. Blood was taken for lactate concentration
([LA]), epinephrine concentration ([Epi]), norepinephrine
concentration ([NE]), plasma renin activity (PRA), human growth
hormone concentration ([hGH]), testosterone, and cortisol
determination. Reduction of peak oxygen uptake
(
O2 peak) after BR was greater in the
endurance athletes than in the remaining groups (17 vs. 10%).
Decrements in O2 peak correlated positively with the initial values (r = 0.73, P < 0.001). Resting and exercise respiratory exchange
ratios were increased in athletes. Cardiac output was unchanged by BR
in all groups, but exercise HR was increased and SV diminished in the
sedentary subjects. The submaximal [LA] and [LA] thresholds were
decreased in the endurance athletes from 71 to 60%
O2 peak (P < 0.001); they also had an earlier increase in [NE], an attenuated increase in
[hGH], and accentuated PRA and cortisol elevations during exercise. These effects were insignificant in the remaining subjects. In conclusion, reduction of exercise performance and modifications in
neurohormonal response to exercise after BR depend on the previous level and mode of physical training, being the most pronounced in the
endurance athletes.
exercise tolerance; blood lactate threshold; catecholamines; hormones; plasma renin activity
This article has been cited by other articles:
|
|
 |
|
  S. M. C. Lee, S. M. Schneider, W. L. Boda, D. E. Watenpaugh, B. R. Macias, R. S. Meyer, and A. R. Hargens LBNP exercise protects aerobic capacity and sprint speed of female twins during 30 days of bed rest J Appl Physiol, March 1, 2009; 106(3): 919 - 928. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. A. Berlin, W. J. Kop, and P. A. Deuster Depressive mood symptoms and fatigue after exercise withdrawal: the potential role of decreased fitness. Psychosom Med, March 1, 2006; 68(2): 224 - 230. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. P. Kenny, J. E. Murrin, W. S. Journeay, and F. D. Reardon Differences in the postexercise threshold for cutaneous active vasodilation between men and women Am J Physiol Regulatory Integrative Comp Physiol, January 1, 2006; 290(1): R172 - R179. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. S. Church, M. J. LaMonte, C. E. Barlow, and S. N. Blair Cardiorespiratory Fitness and Body Mass Index as Predictors of Cardiovascular Disease Mortality Among Men With Diabetes Arch Intern Med, October 10, 2005; 165(18): 2114 - 2120. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. S. Church, Y. J. Cheng, C. P. Earnest, C. E. Barlow, L. W. Gibbons, E. L. Priest, and S. N. Blair Exercise Capacity and Body Composition as Predictors of Mortality Among Men With Diabetes Diabetes Care, January 1, 2004; 27(1): 83 - 88. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
