Energetics of best performances in track cycling

(V) over dot O-2max 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. Steady-state (V) over dot O-2 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 (C-c, J.m(-1)) was calculated as the ratio of (V) over dot O-2, corrected for glycolytic energy production and expressed in W, to v (m.s(-1)). Individual relationships between C-c and v were described by: C-c = C-c pi + k' v(2) where C-c pi is the energy spent against friction and k' v(2) is that spent against drag. Overall energy cost of cycling (C-cbx)tained, adding to C-c 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 ((E) over dot(max), W) is a known function of the exhaustion time (t(e)). It depends on his (V) over dot O-2max and maximal anaerobic capacity; it was obtained from individual (V) over dot O-2max and [La](b) values. The metabolic power ((E) over dot(c), W) necessary to cover any given distance (d) is a known function of the performance time over d (t(d)); it is given by (E) over dot(c) = C-ctot v = C-ctot d t(d)-(1). For all subjects and distances, the t values solving the equalities (E) over dot(max) F(t(e)) = (E) over dot(c), F(t(d)) 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.