A 1-day maximal lactate steady-state assessment protocol for trained runners

Purpose: Identification of the maximal lactate steady state (MLSS) involves multiple days of testing. Heart rate (HR), rating of perceived exertion (R PE), breathing frequency (bf), and race pace may be useful in estimating th e MLSS, thus allowing for testing to occur in a single day. The purpose of this investigation was to design a single-session protocol for determining MLSS using HR, RPE, bf, and race pace as predictors. Methods: Twelve endura nce athletes (mean +/- SD, (V) over dot O-2max 64.6 +/- 7.8 mL.kg(-1).min(- 1)) performed the MLSS protocol run and two 27-min validation runs on a tre admill. Running velocity at 87% HRmax, RPE of 12, bf of 32 breaths.min(-1), and race pace were used as a starting point for testing. Blood was collect ed every 3 min of each 9-min stage of the protocol run and analyzed for lac tate (La) concentration. The velocity associated with the MLSS was determin ed as the average of the stage of La steady state and the stage of La accum ulation. Validation runs were performed at a velocity 7.5 m.min(-1) below a nd 7.5 m.min(-1) above the protocol-determined MLSS. If the slower run exhi bited a La steady state and the faster run an accumulation of La, then the protocol-determined MLSS value was considered valid. Results: The protocol run was successful in predicting the MLSS in 9 out of 12 subjects (P less t han or equal to 0.05). Conclusions: The proposed protocol employing HR, RPE , bf, and race pace as a starling point for testing can be used to identify the MLSS in one resting session.