Effect of 3 weeks of detraining on the resting metabolic rate and body composition of trained males.
OBJECTIVE
To examine the hypothesis that detraining decreases the resting metabolic rate (RMR) of long-term exercisers.


METHODS
Eight pairs of subjects were matched for age, mass and training volume. They were then randomly allocated to either a control group (continue normal training) or detraining group (stop normal training but continue activities of daily living).


METHODS
Exercise Physiology Laboratory, The Flinders University of South Australia.


METHODS
Sixteen male subjects (age 23.1 +/- 4.7 y (s.d.); mass 73.73 +/- 8.9 kg; VO2max 60.2 +/- 6.3 ml. kg-1.min-1; height 180.3 +/- 5.0 cm; body fat 14.6 +/- 5.4%) were selected from a pool of respondents to our advertisements.


METHODS
Each pair of subjects was measured before and after a 3-week experimental period.


RESULTS
Two (groups) x 3 (2-, 3-and 4-compartment body composition models) ANOVAs were conducted on the difference between the pre- and post-treatment scores for percentage body fat, fat-free mass (FFM) and relative RMR (kJ.kg FFM-1.h-1). No significant between-group differences were identified except for the detraining group's small decrease in FFM (0.7 kg, P = 0.05). The main effects for body composition model were all significant; but the overall differences between the multicompartment models and the 2-compartment one were less than their technical errors of measurement. No significant interaction (P = 0.51) resulted from a 2 x 2 ANOVA on the pre- and post-treatment absolute RMR data for the control (315.2 and 311.9 kJ/h) and detraining groups (325.4 and 325.5 kJ/h).


CONCLUSIONS
3-weeks detraining is not associated with a decrease in RMR (kJ/h, kJ.kg FFM-1.h-1) in trained males; hence, our data do not support a potentiation of the RMR via exercise training. The greater sensitivity of the multicompartment models to detect changes in body composition was of marginal value.
LaForgia
J
J
Exercise Physiology Laboratory, School of Education, Flinders University of South Australia, Adelaide, Australia.
Withers
R T
RT
Williams
A D
AD
Murch
B J
BJ
Chatterton
B E
BE
Schultz
C G
CG
Leaney
F
F
D000328:Adult; D000704:Analysis of Variance; D001481:Basal Metabolism; D001823:Body Composition; D002153:Calorimetry, Indirect; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D008954:Models, Biological; D013177:Sports / Q000502:physiology*