Is a retrospective RPE appropriate in soccer? Response shift and recall bias

This study examined the acceptability of a retrospective rating of perceived exertion in soccer. Two attributes were investigated: response shift and recall bias. Response shift refers to a change in perception due to changes in internal standards and recall bias can influence the response shift assessment. Ratings were collected with the Borg-CR100 (R) scale. Study 1: during competitive season 58 players (age 22 +/- 5 years, height 178 +/- 6 cm, body mass 72 +/- 6 kg) were asked their rating following cessation of the matches and again at48 h post match. Response shift (first part of the season) was investigated by difference between the two ratings and recall bias (second part of the season) asking players whether they remembered exactly the rating given 48 h before. No response shift or recall bias were found. Study 2: 21 players (age 25 +/- 5 years, height 176 +/- 6 cm, body mass 71 +/- 7 kg) were asked ratings at the end and 48 h following a field session, equated for internal and external loads. The same session was repeated after 10 days in a randomized crossover design. No significant differences (P > 0.05) between conditions were found. Retrospective rating was appropriate, however, the inconsistency of some ratings (i.e., after training) suggested it should be used only under special circumstances.