The Acute: Chronic Workload Ratio Is Associated with Injury in Junior Tennis Players

Session RPE (sRPE) is used to track internal training/competition load in athletes using a metric known as the acute to chronic workload ratio (ACWR). Research that reported on team sports has determined that if the acute load is higher than the chronic load, athletes are likely to sustain injury. No studies, however, have attempted to investigate internal load and injury in a tennis population despite the rigorous training loads. Therefore, the purpose of this study was to investigate if sRPE ACWR is associated with injury in junior tennis players over a 7-month time period.

Forty-two junior tennis players were recruited to participate, 26 were included in the final analysis. Players provided a rating of RPE as an estimate of training intensity every day after training/match sessions. sRPE, a measure of internal and external training load was calculated by multiplying the training/match sRPE by the session duration in minutes. Players self-reported all injuries. The ACWR was the primary independent variable. Acute load was determined as the total sRPE for 1 wk, whereas a 4-wk rolling average sRPE represented chronic load.

Seventeen players sustained injuries. The model indicated that ACWR from the previous week (P < 0.001) and previous injury history (P = 0.003) were significant predictors of injury the following week. In the week preceding injury, the average ACWR was 1.57 (SD, 0.90).

Injured players had on average 1.5 times more training load in the past week compared with the previous 4 wk. A majority of players who went on to sustain an injury were not prepared for the load endured. These results were similar to previous studies investigating ACWR where an acute increase in load was associated with increased injury risk.