LAUSR

Abstract The study aimed to assess the effect of different front crawl stroke rates (SRs) in the oxygen uptake (̇VO 2 ) kinetics and ̇VO 2 peak, the total time to exhaustion (TTE), and blood lactate concentration ([La]) at 95% of the 400-m front crawl test (T400) mean speed (S400). Twelve endurance swimmers performed a T400 and four trials at 95% of the S400: (i) free SR, (ii) fixed SR (100% of the average free SR trial), (iii) reduced SR (90% of the average free SR trial), and (iv) increased SR (110% of the average free SR trial). ̇VO 2 was accessed continuously with breath-by-breath analysis. The results highlighted: (i) the time constant at increased SR (13.3±4.2 s) was lower than in the reduced SR condition (19.5±2.6 s); (ii) the amplitude of the primary phase of ̇VO 2 kinetics in the fixed SR (44.0±5.8 ml·kg -1 ·min -1 ) was higher than in the increased SR condition (39.5±6.4 ml·kg -1 ·min -1 ); and (iii) TTE was lower in the fixed SR (396.1±189.7 s) than the increased SR condition (743.0±340.0 s). The results indicate that controlled SR could be considered a swimming training strategy, focusing on physiological parameters overload.