Subjective Perceived Exertion in the Judo Athletes Session: Seven Weights and One Measure? Letter to the Editor

Firstly, we would like to congratulate the authors of the article “Training monitoring in judo: comparison between the load intensity planned by the coach and the intensity perceived by the athlete”1 on their initiative to investigate a theme this relevant to the training load control. Additionally, we should state that the conclusion is at first surprising: “...although the training program has been designed by experienced coaches, difference between the external load intensity expected by the coach and the internal load intensity perceived by the athlete was detected.”1 (p. 268). However, reflexion on the methods applied may help to understand the results: 1) judo is practiced in seven categories concerning body mass in both genders, and its subgroups resulting from these divisions are quite distinct concerning physical fitness (v.g., Franchini et al.2). Although the group participated in the same training camp, it is not very probable that the athletes were in the same periodization phase, since fighters of different levels participate in the distinct competition phases of the world ranking system. These two factors affect the subjective perceived exertion (SPE) during the session3; 2) the time of interval between the randori repetitions is not mentioned in the session description, which would be important since this variable remarkably interferes in the physiological response (oxygen consumption and heart rate, for instance) during the performance of this kind of activity4; 3) it is not mentioned whether the subjects involved in the use of this scale are familiar with it, which would be important since acceptable results measured by the concordance limits seem to be found after three sessions when the participant is exposed to different exercise intensities3. Especially concerning the coaches, this information seems to be crucial for suitable classification of the session, mainly due to the fact that the scale has not been validated yet for the modality. Another question which may be raised is whether the coaches would not be planning the intensity of the session having the athletes with best physical fitness as basis; 4) the statistical procedures need to be revised, since it is not clear how the Student’s t test assumptions were fulfilled for comparison of the SPE of the coaches and athletes, the reason why the lactate concentration data were reported as mean and standard deviation, if non-parametric statistics has been applied and also how the Wilcoxon test was sufficient to compare multiple moments5; 5) there are studies which reported data contrary to what has been reported in the study for the SE and lactate correlation, e.g., higher values of lactate and low/moderate of SPE6-9, which would occur due to the dissociation between SPE and intensity of the activities in the fights due to the strong attention focus on the opponent’s actions6; and 6) the randori volume reported is extremely high and the intensities expected by the coaches were between 3 and 5, showing that the focus seemed to be more technical than of physical fitness development, a fact which is corroborated by the low lactate concentration values after training compared to what is commonly observed after fight simulation or competitions10.