Energetics of best performances in track cycling CAPELLI , CARLO ; SCHENA , FEDERICO ; ZAMPARO , PAOLA

̇VO2max and best performance times (BPTs) obtained during maximal voluntary trials over 1, 2, 5, and 10 km from a stationary start were assessed in 10 elite cyclists. Steadystate ̇VO2 and peak blood lactate concentration ([La]b) were also determined in the same subjects pedaling on a track at constant submaximal speeds. The energy cost of cycling(Cc, J·m-1) was calculated as the ratio of ̇VO2, corrected for glycolytic energy production and expressed in W, to v (m·s-1). Individual relationships between Cc and v were described by: Cc = Ccrr + k′ v2 where Ccrr is the energy spent against friction and k′ v2 is that spent against drag. Overall energy cost of cycling (Cctot) was obtained, adding to Cc the energy spent to accelerate the total moving mass from a stationary start. Individual theoretical BPTs were then calculated and compared with the actual ones as follows. The maximal metabolic power sustained at a constant level by a given subject (Ėmax, W) is a known function of the exhaustion time (te). It depends on his ̇VO2max and maximal anaerobic capacity; it was obtained from individual ̇VO2max and [La]b values. The metabolic power(Ėc, W) necessary to cover any given distance (d) is a known function of the performance time over d (td); it is given byĖc = Cctot v = Cctot d td-. For all subjects and distances, the t values solving the equalities Ėmax F(te) = Ėc F(td) were calculated and assumed to yield theoretical BPTs. Calculations showed a fairly good agreement between actual and calculated BPTs with an average ratio of 1.035 ± 0.058. 17/03/11 09.03 Energetics of best performances in track cycling : Medicine & Science in Sports & Exercise Pagina 2 di 22 http://journals.lww. com/acsm-msse/Fulltext/1998/04000/Energetics_of_best_performances_in_track_cycling. 21.aspx It has been shown (25) that the best performances in track running over distances between 800 and 5000 m can be predicted with fairly good accuracy provided that the individual energy cost of running and the individual maximal metabolic power are known. The model that makes this possible is discussed in detail in(25) and is summarized in theAppendix of this paper. In summary, the energy cost (C) represents the amount of energy required above resting to transport the runner's body over one unit of distance and that the maximal metabolic power(Ėmax) is inclusive of the fraction derived from anaerobic energy stores utilization. The aim of the present paper was to test the accuracy of the same model when applying it to track cycling, that is, to a type of locomotion whose energy cost (at variance with running) increases with speed. Hence we measuredĖmax and the overall energy cost of track cycling (Cctot) as a function of the speed in a group of young, high level cyclists. This made it possible to calculate the theoretical best performance times over the distances of 1, 2, 5, and 10 km. The theoretical values were finally compared to the actual times measured during coeval racing trials over the same distances. MATERIALS AND METHODS Subjects. Ten male subjects, whose main physiologic and anthropometric characteristics are reported in Table 1, participated in the study. Two of 10 were professional road cyclists (L. N. and D. R.), whereas the others were competing in national-level amateur road races. The study was performed after the end of the racing season; however, the athletes maintained their usual training intensity during the entire period of the experiments. The subjects were thoroughly informed about the aims and details of the experimental protocol, which was approved by the Ethical Committee of the School of Medicine of the University of Udine, and were asked to sign an informed consent.