Scaling behaviour of VO2 in athletes and untrained individuals.
OBJECTIVE
The present study analysed the allometric relationship (MR = a . M(b)) between human metabolic rate (MR), ranging from resting to maximal metabolic conditions, and body mass (M ), both in athletes of different specialization and untrained individuals.


METHODS
Two hundred and seventy male athletes and 43 untrained men performed a continuous incremental test to volitional exhaustion on a motorized treadmill. Metabolic rate (i.e. VO2) was measured during resting (VO2REST), sub-maximal (walking at 5 km h(-1) VO2WALK; running at 7.5 km h(-1) VO2RUN; ventilatory anaerobic threshold VO2VT) and maximal exercise conditions (maximum oxygen uptake VO2MAX).


RESULTS
A significant difference (p < 0.001) in the MR-body mass relationships between athletes and controls was found. For the control group, the mass exponent b exhibited a non-significant (p = 0.37) increase with increasing metabolic demand (b = 0.69, 0.76, 0.76, 0.84, and 0.89, for VO2REST, VO2WALK, VO2RUN, VO2VT, and VO2MAX, respectively). In contrast, the corresponding mass exponent for the athletic group significantly (p < 0.01) decreased when moving from resting to maximal metabolic conditions (b = 0.98, 0.88, 0.80, 0.69, and 0.67).


CONCLUSIONS
These results indicate that the recently proposed allometric cascade model may be valid in describing the scaling behaviour of MR in untrained individuals, but not in athletes of different specialization.
Markovic
Goran
G
Faculty of Kinesiology, Department of Kinesiology of Sport, University of Zagreb, Croatia.
Vucetic
Vlatko
V
Nevill
Alan M
AM
D000328:Adult; D001481:Basal Metabolism; D015992:Body Mass Index; D049628:Body Size; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D005082:Physical Exertion / Q000502:physiology*; D013177:Sports / Q000502:physiology*