Heart rate and blood lactate correlates of perceived exertion during small-sided soccer games

The rating of perceived exertion (RPE) could be a practical measure of global exercise intensity in team sports. The purpose of this study was to examine the relationship between heart rate (%HRpeak) and blood lactate ([BLa-]) measures of exercise intensity with each player's RPE during soccer-specific aerobic exercises. Mean individual %HRpeak, [BLa-] and RPE (Borg's CR 10-scale) were recorded from 20 amateur soccer players from 67 soccer-specific small-sided games training sessions over an entire competitive season. The small-sided games were performed in three 4 min bouts separated with 3 min recovery on various sized pitches and involved 3-, 4-, 5-, or 6-players on each side. A stepwise linear multiple regression was used to determine a predictive equation to estimate global RPE for small-sided games from [BLa-] and %HRpeak. Partial correlation coefficients were also calculated to assess the relationship between RPE, [BLa-] and %HRpeak. Stepwise multiple regression analysis revealed that 43.1% of the adjusted variance in RPE could be explained by HR alone. The addition of [BLa-] data to the prediction equation allowed for 57.8% of the adjusted variance in RPE to be predicted (Y = -9.49 - 0.152 %HRpeak + 1.82 [BLa-], p < 0.001). These results show that the combination of [BLa-] and %HRpeak measures during small-sided games is better related to RPE than either %HRpeak or [BLa-] measures alone. These results provide further support the use of RPE as a measure of global exercise intensity in soccer. © 2007 Sports Medicine Australia.