engleski

Scaling behaviour of VO2 in athletes and untrained individuals

Objective: The present study analysed the allometric relationship (MR = a · Mb) 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. Subjects and 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, O2vt, 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). Conclusion: 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.

metabolic scaling ; resting metabolic rate ; maximal oxygen uptake ; exercise ; metabolism ; body size

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