Within-Week Variations and Relationships between Internal and External Intensities Occurring in Male Professional Volleyball Training Sessions

Abstract

The purpose of the study was to test the within-week variations of the internal and external training intensity outcomes organized by days of the week. An 8-month observational period was conducted during the 2020–2021 season. The training sessions and matches of an elite volleyball team were monitored daily. The data comes from 14 players (two setters, five middle blockers, five outside hitters, and two opposites) of an elite team from the Portuguese 1st League (age: 21.7 ± 4.19 years of age; experience: 6.2 ± 3.8 years; body mass: 85.7 ± 8.69 kg; height: 192.4 ± 6.25 cm; BMI: 23.1 ± 1.40 kg/m2). The CR10 Borg scale was applied daily to measure the training intensity. The rate of perceived exertion (RPE) and the session-RPE were extracted as the internal outcomes. The external intensity was measured using an inertial measurement unit (IMU). The number of jumps, height average of jumps (JHA), minimum jump (MJ), maximal jump (MXJ), range jump (RJ), number of jumps (NJ), and training session density (D) were extracted as external intensity outcomes. The results showed that there was a difference between RPE and S-RPE (F (1.98) = 6.31, p = 0.01, η2 = 0.36, and F (1.73) = 28.30, p = 0.001, η2 = 0.72), as well as JHA and NJ (F (2.14) = 4.76, p = 0.02, η2 = 0.30, and F (1.77) = 4.77, p = 0.02, η2 = 0.30) within the microcycle. When analyzing the correlations between internal and external intensity, it was observed that there was a negative correlation between the Maximum Jump (4, 3, and 1 days before the Match day) (r2 = 0.34, r2 = 0.40, r2 = 0.41, respectively) and the Range Jump (3 and 1 days before the Match day (r2 = 0.33, r2 = 0.38, respectively) with the RPE (4 days before the Match day) and Maximum Jump (5, 4, 3, and 1 days before the Match day (r2 = 0.35, r2 = 0.39, r2 = 0.44, r2 = 0.34, respectively) and Range Jump (5, 4, 3, and 1 days before the Match day) (r2 = 0.34, r2 = 0.35, r2 = 0.40 and r2 = 0.36, respectively) with S_RPE (4 days before the Match day). Such findings show that higher internal intensities are correlated with lower external intensities in sessions further away from the game day. Such results could be an important tool for coaches to reflect, plan, monitor, and execute the training unit according to the temporal distance to the competition.

Within-week and between-week variability of external and internal load demands of professional male volleyball players

“…On this basis, coaches minimise the training period on MD-1 to minimise the workload due to the impending competition [36]. Similar results were found in studies by Akyildiz et al [55] and Lima et al [43], which tried to analyse the withinweek variations and relationships between internal and external workload and found a decrease in the jump load throughout the week when approaching a match day.…”

“…However, a previous study [38], which characterised the external and internal training load of professional volleyball players with a focus on intra-week changes, found significant differences between MD-2 and MD-1, registering a higher number of jumps on MD-2. These results are an important highlight, which demonstrate that the number of jumps decreases across the week due to the proximity of the match day [35,43,57].…”

“…and is calculated as the product of the Borg scale rating and the duration of the training session [39]. The sRPE has been applied in several studies and is considered a valid surrogate of internal load [40][41][42][43][44]. The main outcomes extracted for each training session were the individual RPE score and the individual sRPE.…”

“…The primary outcomes derived from the data analysis included the number of jumps and the height of each jump. Furthermore, the following calculations were performed for each session: average jump height, minimum jump height, maximum jump height, range of jump heights, total number of jumps, and jump density (number of jumps per unit of time) [42,43].…”