A Single-Phase Modelling for the Oxygen Uptake Rate in Excess Post-Exercise Oxygen Consumption

A two-parameters [a rate constant k and a factor f (0≤ f  < 1)] modelling, describing satisfactorily the post-exercise oxygen uptake rate ( V O2 ) as a function of the recovery time ( t ), is presented. f controls the rate equation d V O2 /d t , particularly at t  = 0 where (d V O2 /d t ) t =0 ∝ − k (1− f ), a less abrupt decay than (d V O2 /d t ) t =0 ∝ − k expected from an exponential. Fitting the model to a set of experimental V O2 vs t data after a 3MT it was found a set of values with f close to 0 and another with f  > 1/2, with a narrow distribution of values for the half-recovery time τ 1/2 =(1/ k )ln[(2− f )/(1− f )] (〈 τ 1/2 〉=0.641 min, σ  = 0.062 min), very similar to that ( T ) found by fitting a model based on a logit transform (〈 T 〉 = 0.672 min, σ  = 0.081 min). The parameter f is a reliable index of the initial acceleration of the oxygen uptake rate recovery (and likely of the heart rate recovery) and, together with the half-recovery time τ 1/2 , may be a useful method in characterizing and monitoring performs and exercise forms, very important in the physiology area.