Incremental Swimming Test Provides Key Determinants of 200-m Front Crawl Race Performance.

PURPOSE: This study examined whether lactate-derived indices were associated with 200-m front crawl race performance. METHODS: Twenty-eight highly trained male swimmers (18.0 [3.2] y) performed a 7 × 200-m incremental step test, and the speed corresponding to lactate threshold (LT) was determined from the speed-lactate curve. The blood lactate increase speed (BLISLT-peak) was calculated as the ratio of the difference between blood lactate concentration at LT and peak blood lactate by the time required to complete the fastest 200-m repetition of the 7 × 200-m test. The rate of blood lactate increase from LT to the peak lactate value (BLrateLT-peak) was calculated by the slope of the corresponding points of the speed-lactate curve. Official 200-m race performance times were recorded and used as the dependent variable. Multiple linear regression was applied to assess the validity of BLISLT-peak and BLrateLT-peak as predictors of 200-m race performance. RESULTS: The regression model, including speed corresponding to LT and BLISLT-peak, explained 74% of the performance variance. Inclusion of BLrateLT-peak increased explained variance to 80% (adjusted R2 = .77). In this model, LT speed (β = -0.78, P = .01), BLISLT-peak (β = -0.41, P = .01), and BLrateLT-peak (β = -0.31, P = .01) were all significant independent predictors. CONCLUSION: Lactate-derived indices from the incremental step test (LT speed, BLISLT-peak, and BLrateLT-peak) were associated with 200-m swimming performance, explaining 80% of the variance. These findings indicate that the protocol may have practical value for physiological profiling in 200-m swimmers.