COMPARISON OF A FIELD-BASED TEST TO ESTIMATE FUNCTIONAL THRESHOLD POWER AND POWER OUTPUT AT LACTATE THRESHOLD

Gavin, TP, Van Meter, JB, Brophy, PM, Dubis, GS, Potts, KN, and Hickner, RC. Comparison of a field-based test to estimate functional threshold power and power output at lactate threshold. J Strength Cond Res 26(2): 416-421, 2012-It has been proposed that field-based tests (FT) used to estimate functional threshold power (FTP) result in power output (P0) equivalent to PO at lactate threshold (LT). However, anecdotal evidence from regional cycling teams tested for LT in our laboratory suggested that PO at LT underestimated FTP. It was hypothesized that estimated FTP is not equivalent to PO at LT. The LT and estimated FTP were measured in 7 trained male competitive cyclists ((V) over dotO(2)max = 65.3 +/- 1.6 ml O-2.kg(-1).min(-1)). The FTP was estimated from an 8-minute FT and compared with PO at LT using 2 methods; LT Delta 1, a 1 mmol.L-1 or greater rise in blood lactate in response to an increase in workload and LT4.0, blood lactate of 4.0 mmol.L-1. The estimated FTP was equivalent to PO at LT4.0 and greater than PO at LT Delta 1. (V) over dotO(2)max explained 93% of the variance in individual PO during the 8-minute FT. When the 8-minute FT PO was expressed relative to maximal PO from the (V) over dotO(2)max test (individual exercise performance), (V) over dotO(2)max explained 64% of the variance in individual exercise performance. The PO at LT was not related to 8-minute FT PO. In conclusion, FTP estimated from an 8-minute FT is equivalent to PO at LT if LT4.0 is used but is not equivalent for all methods of LT determination including LT Delta 1.