Muscle efficiency improves over time in world-class cyclists.
OBJECTIVE
To determine the change in muscular efficiency in world-class professional cyclists during years of training/competition.


METHODS
Twelve male world-class professional road cyclists (mean +/- SD: age = 22.6 +/- 3.8 yr and VO(2max) = 75.5 +/- 3.3 mL x kg(-1) x min(-1)) performed an incremental test (starting at 100 W with workload increases of 50 W every 4-min interval until volitional exhaustion) before and after a five-season period. Delta efficiency (DE) was calculated from 100 W to that power output (PO) in which the RER was 1.


RESULTS
DE increased (P < 0.01) from 23.61 +/- 2.78% to 26.97 +/- 3.7% from the first to the fifth year, whereas VO(2max) showed no significant increase. A significant inverse correlation (r = -0.620; P = 0.032) between DE and VO(2max) (mL x kg(-1) x min(-1)) was found in the fifth year, whereas no significant correlation between these variables was found in the first year. A significant inverse correlation (r = -0.63; P = 0.029) was found between the increase percentage in DE (DeltaDE) and VO(2max) (mL x kg(-1) x min(-1)) in the fifth year, whereas no significant correlation was found between these variables in the first year.


CONCLUSIONS
The results show an increase in DE in world-class professional cyclists during a five-season training/competition period, without significant variations in VO(2max). The results also suggest that the increase in DE could be a possible way for performance compensation, especially in those subjects with lower VO(2max).
Santalla
Alfredo
A
Departamento de Deportes e Informática (despacho 11.1.30), Pablo de Olavide University, Seville, Spain. asanher@upo.es
Naranjo
José
J
Terrados
Nicolás
N
D000293:Adolescent; D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001642:Bicycling; D005080:Exercise Test; D006801:Humans; D007866:Leg; D008297:Male; D053580:Muscle Strength / Q000502:physiology; D018482:Muscle, Skeletal / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D055815:Young Adult