Blood Lactate, Rate of Perceived Exertion and Mean Heart Rate Can Predict Success in Squash Players

Squash is a popular racket sport that requires intermittent activity near maximal-intensity exercise. The aim of this study is to analyse the sensitivity (Sens) and specificity (Spec) of the physiological response variables to predict the outcome in competition. Thirteen regional and national male Spanish squash players [mean (SD) age 34. 3 (10. 1); weight 74. 6 (5. 1) and height 173. 9 (7. 2) were participants in the study. Mean heart rate (MHR), blood lactate (BLa) concentrations and rate of perceived exertion (RPE) were measured as physiological parameters in 22 official squash sets. Received operating characteristics (ROC) analyses were performed. Differences were found between winners and losers in blood lactate levels (3. 41 mMol/L +/- 1. 58 mMol/L vs. 6. 54 mMol/L +/- 2. 86 mMol/L, P < 0. 002, respectively) and Borg Scale (5. 5 mMol/L +/- 2.3 mMol/L vs. 7.6 mMol/L +/- 2. 43 mMol/L, P <0. 03) and no differences was found in mean heart rate (167 bpm +/- 12 bpm vs. 175 bpm +/- 9. 5 bpm, P > 0.05). Areas under curve (AUC) of BLa were 0. 93 0. 05, 95% CI 0. 741 to 0.995, (P <0. 0001), RPE 0. 754 +/- 0. 113, 95% CI 0. 526 to 0. 910, (P = 0.02) and MHR 0. 729 +/- 0. 112, 95% CI 0. 500 to 0. 894 (P = 0. 04). Optimal cut-off points for BL were 4. 67 mMol/L, (Sens 91. 67% and Spec 90. 00%), for RPE 7 (Sens 83. 33% and Spec 70. 00%) and MHR 172 bpm (Sens 66. 6% and Spec 80. 00%). Blood lactate and rate of perceived exertion cut-off points can be used as specific-training physiological parameters.