Training Load and Injuries in Volleyball: An Approach Based on Different Methods of Calculating Acute to Chronic Workload Ratio.

Background: Many questions persist regarding the relationship between training load and injuries in volleyball, as well as the best method for calculating acute:chronic workload ratio (ACWR). This study aimed to investigate the relationship between different metrics of training load and risk of injury in male professional volleyball players.

Hypothesis: ACWR, as a training load measure, is useful for identifying injury risk in volleyball players, regardless of calculation method.

Study design: Longitudinal, prospective, and observational design conducted over 3 seasons of professional male volleyball.

Level of evidence: Level 3.

Methods: The study included 43 male volleyball players. Internal training load was quantified using the Session Rating of Perceived Exertion. From daily training load values, absolute measures and relative measures were computed. For relative measures, 7 days were employed for acute training load, and 21 and 28 days for chronic training load. A distinction was made between coupled calculation and uncoupled calculation. Injuries were documented using the Injury Surveillance Form proposed by the International Volleyball Federation.

Results: ACWR calculated in a coupled manner and by a rolling average demonstrated higher injury risks when analyzing the complete periods (odds ratio [OR] ACWR 7:28 = 2.040; ACWR 7:21 = 1.980) and competitive period (OR ACWR 7:28 = 2.044; ACWR 7:21 = 2.087). In contrast, during the preseason, the coupled exponential averages were more sensitive to the risk of injury (OR ACWR 7:28 = 4.370; ACWR 7.504).

Conclusion: Both measures using rolling averages and those calculated from exponential averages can be employed to identify the risk of injuries in volleyball athletes.

Clinical relevance: The findings of this study can be useful to coaching staff, fitness trainers, and healthcare professionals involved in the challenge of reducing the risk of injury in volleyball athletes. The need for continuous monitoring and real-time adjustments of training load is emphasized.