Training load, recovery times and injuries in elite rugby league players

Summary of an article analyzing acute and chronic workloads and their relation to injuries in elite rugby league players.

Who

28 male elite rugby league players aged 24.8 (±3.4) (Australia).

Design

Observation over two Australian National Rugby League (NRL) seasons. One club.

Outcome measures

injury (“any time-loss injury that resulted in a player being unable to complete full training, or missing match time” recorded by senior physiotherapist)
between-match recovery time: short (<7 days) or long (7 days or more)
workload (GPS): total distance [m]
acute workload (1 week workload), chronic workload (previous 4-week average of weekly workloads), ACWR (Acute:chronic workload ratio)

ACWR – Acute:chronic workload ratio = a ratio of traning load acummulated over the recent week and the training load accumulated over the previous 4 weeks

Main results

In two seasons there were 44 match injuries and 9 training injuries. No difference in risk for match injury was following short versus long recovery time.
For short between-match recovery times, the risk of injury was the lowest for high between-match workload.
During short between-match recovery:
- players were at 2.88 times higher risk of match injury when they ACWR was high (1.23-1.61), than when ACWR it was moderate-high.
- the risk of match injury for ACWR very-high (≥1.62) was 5.8 times higher than for moderate-high ACWR and 3.41 times higher than for low ACWR.
As the chronic workload increased, the risk of sustaining subsequent match injury decreased lineary.
For long between-match recovery times, the risk of match injury for very-high ACWR (≥1.50) was 4.46 times higher than for moderate-high ACWR.

Take home message

For a clinician & coach

In elite rugby league players, no difference in match injury risk was found between short (7.7% risk) versus long (6.8% risk) recovery times. Higher chronic workloads seem to reduce the risk for match injuries when the recovery time is low. Higher ACWR are associate with increased risk of match injury.

For a parent

In elite rugby league players, big spikes in workload increase the risk for an injury. The amount of rest days between matches does not influence the risk of injury.

For an athlete

If you are an elite rugby player, please know that big spikes in workload are likely to increase your risk for an injury. The number of days between matches does not influenc your risk of sustaining an injury.

Original article

Hulin BT, Gabbett TJ, Caputi P, Lawson DW, Sampson JA. Low chronic workload and the acute: chronic workload ratio are more predictive of injury than between-match recovery time: a two-season prospective cohort study in elite rugby league players. Br J Sports Med. 2016 Aug 1;50(16):1008-12.