Weekly Load Variations of Distance-Based Variables in Professional Soccer Players: A Full-Season Study

Abstract

The aim of this study was two-fold: (1) to analyze the variations of acute load, training monotony, and training strain among early (pre-season), mid (first half of season), and end season (second half of season) periods; (2) to compare these training indicators for playing positions in different moments of the season. Nineteen professional players (age: 26.5 ± 4.3 years; experience as professional: 7.5 ± 4.3 years) from a European First League team participated in this study. The players were monitored daily over a 45-week period for the total distance (TD), distance covered (DC) at 14 km/h−1 or above (DC > 14 km/h), high-speed running above 19.8 km/h−1 (HSR) distance, and number of sprints above 25.2 km/h−1. The acute load (sum of load during a week), training monotony (mean of training load during the seven days of the week divided by the standard deviation of the training load of the seven days), and training strain (sum of the training load for all training sessions and matches during a week multiplied by training monotony) workload indices were calculated weekly for each measure and per player. Results revealed that training monotony and training strain for HSR were meaningfully greater in pre-season than in the first half of the in-season (p ≤ 0.001; d = 0.883 and p ≤ 0.001; d = 0.712, respectively) and greater than the second half of the in-season (p ≤ 0.001; d = 0.718 and p ≤ 0.001; d = 0.717). The training monotony for the sprints was meaningfully greater in pre-season than in the first half of in-season (p < 0.001; d = 0.953) and greater than the second half of in-season (p ≤ 0.001; d = 0.916). Comparisons between playing positions revealed that small-to-moderate effect sizes differences mainly for the number of sprints in acute load, training monotony, and training strain. In conclusion, the study revealed that greater acute load, training monotony, and training strain occurred in the pre-season and progressively decreased across the season. Moreover, external defenders and wingers were subjected to meaningfully greater acute load and training strain for HSR and number of sprints during the season compared to the remaining positions.

Comparisons of Accelerometer Variables Training Monotony and Strain of Starters and Non-Starters: A Full-Season Study in Professional Soccer Players

“…As mentioned before, our study presented a “w-shape” that could have possible negative effects on the players, but injuries were not analyzed. In opposition to the studies of Clemente et al [ 19 , 20 ], where TM showed a tendency to decrease as the weeks progressed, the present study did not present the same pattern. Indeed, there were variations throughout the full season.…”

“…These results were expected for the first week of training sessions (pre-season), whereat a possible higher training load was applied. Although it was not a purpose of this study to compare different periods of the season, the results are in line with some studies [ 19 , 20 , 29 ], which means that the exercise training program, early in the pre-season, focused on improving physical condition through a higher training load [ 30 ].…”

“…In fact, few studies used this approach of calculating TM and TS [ 19 , 20 , 21 , 23 ]. Lazarus et al [ 23 ] found that TM and TS revealed trivial effects on Australian soccer training performance.…”

“…Indeed, there were variations throughout the full season. However, it is important to highlight that the present study used acceleration and deceleration to calculate TM and TS, and the previous studies mentioned [ 19 , 20 , 21 , 23 ] used session rate of perceived exertion (s-RPE).…”

“…Thus, some studies provided more information when focusing on training monotony (TM: mean of training load during the seven days of the week divided by the standard deviation of the training load of the seven days) and training strain (TS: multiplication of accumulated weekly load by the TM) workload indices [ 19 , 20 , 21 , 22 , 23 , 24 ]. The knowledge of the variations in the load within and between weeks, and these variations’ relationships with the load distribution, is very useful to understand the impact of training strategies imposed by coaches and the physiological adaptations of the players [ 25 ].…”