Manipulation of Stroke Rate in Swimming: Effects on Oxygen Uptake Kinetics

The study aimed to assess the effect of different front crawl stroke rates (SRs) in the oxygen uptake (˙VO ₂) kinetics and ˙VO ₂peak, 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 ₂was 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 ₂kinetics 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.