The RPE scale   is a tool widely used in training session or rehabilitation program    and becomes a valid visual analogic scale to monitor the internal load  . Indeed, in the lasts years the session RPE was used to verify the trainig program  and avoid the overtraining (arbitrary units over than 600 in one week;   ) in several sport. Examples are proposed in soccer  , basketball,  , rugby  , water polo  , gymnastics  , swimming  , diving  , endurance training   or for clinical assessment   and daily living activity  .
To the best of our knowledge, no assessment was verified in individual sport where the coordination skills were strongly implicated and where although the performance (using a tool) is played in closed skill context and in a known routine, the final results could be considered as an open skill outcome.
In this point, a pilot assessment of skating practice was carried out. In particular, a professional skater was assessed using RPE scale during training session and official competition to verify the reliability of the RPE in individual and high level coordination skill performance.
A professionist male skater (25 years, weight = 178 cm; Height = 64 kg) was freely recruited during the sport season 2014/15. He is an expert pratictioner with 13 years of experience (the last 3 as professionist): on average performing 141 ± 37 min/die of practice. In particular, he followed a professionist trainer to improve the physical condition in order to obtained the first place in national challange.
The skater was informed about the procedure and the tools involved in the study and the informed consent was obtained.
The skater was familiarized with the Borg CR-10 scale as indicated by Borg  during preliminary training session in the month of January.
The bouts of conditioning consisted of different kind of training: strenght, power, interval training, high intensity interval training and specific techinical coordination skills using board. Simulation of real challange were also proposed. Table 1 and Table 2 showed an example of week training program. After each day session of training the RPE value was collected (30 min after the end of session, Foster et al.,  ) and then calculated the internal training load (TLsession) about all single session. The training load was detected also during official competition performance (TLperf) at the end of the ninth month of conditioning.
2.3. Data Analysis
The TLsession and TLperf was calculated using the indication of Foster et al.  :
After each mesocycle of training the mean value of training load (TLmean) was
Table 1. The organization of training according to different objective in first period of training (five month). m = morning; a = afternoon.
Table 2. The organization of training according to different objective in second period of training (four month). m = morning; a = afternoon.
then calculated as the average of internal load perceived by the skater during the session.
Figure 1 shows the TLmean while the corresponding mean RPE value was 4.2, s = 0.66. The TLperf during official competition was 1008, s = 127 (RPE = 4.8).
This exploratory study aimed to verify the feasability of RPE scale during the performance of particular individual sport. This is the case of skateboarding. Indeed, skaters are implicated in closed skills performance where the coordinative and conditional ability are involved. Furthermore, the use of a board forces the athlete in “tricks” that are not predictable as an absolute closed skill action.
Thus, a professionist skater was assessed using RPE scale  and TL method  to verify the trend of training session.
The TLperf after the official competition (the challenge implicated five eliminatory sessions of three minutes each) was closed to 1000 u.a. co-
Figure 1. Trend of TLmean during the nine month of conditioning.
rresponding to 4.8 RPE value along 225 min. of competition. This high value of TL is similar to the value found in Olympic athletes  and very similar to those perceived by the skater in the first phase (first five months) of his training period. It seems a good indication/confermation for trainer that could manage the external load to reach similar stress in their athletes.
The value of TLmean during the last four months was less high than the first five months. Indeed, the second part of training was mostly incinerated on com- petition simulation and technical tricks (Table 1 and Table 2). Also, this statement could be useful for trainer and athletes because they could manage the effort in period near the competitions, in particular, considering that the mean RPE was 4.2: very close to 5.5 found in his official competition and similar to the value collected in runner during the first period (10% of total distance covered,   ).
Another consideration for trainer is about overtraining status  . Indeed, a TL over than 600 u.a. in single session is considered a risky status for continuation in training, in recovery or in general health   .
Our skater, on average, did not overtake this cut-off during the competition period and this may be another useful parameter for trainer during practical organization load.
The major limitation of this study was the single skater taken into account but the recruitment in this particular sport was hard due to the limited number of professional player. These restricted results, however, could represent indication for skaters and trainers around the world.
Indeed, this pilot study confirmed the feasability of RPE and TL methods to monitoring the contioning session also in particular sport as the skateboarding. Trainers during their session have to reach their skaters to 1000 u.a., because the most important competiton could reach this value and then the possibility to experience this load is important for a competitor’s perseverance. The mean RPE during session should be between 4 and 5, and the near the comeptition avoids, the long time session or high intensity training to prevent overtraining status.
Further studies will be necessary to improve this pilot analysis. For instance, evaluation of emotive status during competition  or cardiac frequency response could be assessed.
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