Workload is associated with the occurrence of non-contact injuries in professional male soccer players: A pilot study

Influence of the External Workload on Calf Muscle Strain Injuries in Professional Football Players: A Pilot Study

BACKGROUND

The influence of external workload variables on the development of calf muscle strainsin football players has not been previously explored.

HYPOTHESIS

Overloaded players would have an increased risk of calf muscle strain injury.

STUDY DESIGN

Prospective observational study.

LEVEL OF EVIDENCE

Level 4.

METHODS

A total of 41 professional football players from 1 team were monitored for 2 consecutive seasons. Total distance covered (TD), and distances covered at high-intensity running, high sprint running, low (LACC) and high (HACC) acceleration, low (LDEC) and high (HDEC) deceleration, and at high metabolic load distance (HMLD) were monitored with GPS units. Accumulated players' external workload in the week before injury was compared with the weekly mean value of the 6 weeks before injury occurred for each player.

RESULTS

Ten players (24.3%) suffered 16 calf muscle strain injuries (3.1 injuries per 1000 hours of match play; 0.5 injuries per 1000 hours of training exposure). Players with a calf muscle injury were older (p = 0.03), with higher body weight (p = 0.01) and height (p = 0.03). Injured players displayed substantially higher total training volume (p < 0.01), TD (p < 0.01), LACC (p < 0.01), LDEC (p < 0.01), HACC (p < 0.01), HDEC (p < 0.01), and HMLD (p = 0.03) in the week before injury, in comparison with the mean values of these variables in the 6 weeks before injury.

CONCLUSION

A week with a higher-than-habitual external workload might increase the risk of calf muscle strain injury in professional football players. Calf muscle injuries were preceded by a week with unusually high workloads associated with accelerating and decelerating distances and higher training volumes.

CLINICAL RELEVANCE

Monitoring external workload indicators may be helpful in determine players with a higher risk of calf muscle strain injury due to excessive workload during training/competition.

Within-week differences in external training load demands in elite volleyball players

Purpose

The aim of this study was to analyze the within-week differences in external training intensity in different microcycles considering different playing positions in women elite volleyball players.

Methods

The training and match data were collected during the 2020–2021 season, which included 10 friendly matches, 41 league matches and 11 champions league matches. The players’ position, training/match duration, training/match load, local positioning system (LPS) total distance, LPS jumps, accelerations, decelerations, high metabolic load distance (HMLD), acute and chronic (AC) mean and AC ratio calculated with the rolling average (RA) method and the exponentially weighted moving average (EWMA) method, monotony and strain values were analyzed.

Results

All the variables except strain, Acc/Dec ratio and acute mean (RA) showed significant differences among distance to match days. Regarding the players’ positions, the only difference was found in the AC ratio (EWMA); in all microcycles, the middle blocker player showed workload values when compared with the left hitter, setter and libero.

Conclusion

Overall, the analysis revealed that the intensity of all performance indicators, except for strain, acc/dec and acute mean load (RA), showed significant differences among distance to match day with moderate to large effect sizes. When comparing players’ positions, the middle blocker accumulated the lowest loads. There were no significant differences among other positions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13102-022-00568-1.