The acute:chronic workload ratio predicts injury: high chronic workload may decrease injury risk in elite rugby league players

Abstract

Aim Investigate whether acute workload (1 week total distance) and chronic workload (4-week average acute workload) predict injury in elite rugby league players. Methods Data were collected from 53 elite players over two rugby league seasons. The 'acute:chronic workload ratio' was calculated by dividing acute workload by chronic workload. A value of greater than 1 represented an acute workload greater than chronic workload. All workload data were classified into discrete ranges by z-scores. Results Compared with all other ratios, a very-high acute:chronic workload ratio (≥2.11) demonstrated the greatest risk of injury in the current week (16.7% injury risk) and subsequent week (11.8% injury risk). High chronic workload (>16 095 m) combined with a veryhigh 2-week average acute:chronic workload ratio (≥1.54) was associated with the greatest risk of injury (28.6% injury risk). High chronic workload combined with a moderate workload ratio (1.02-1.18) had a smaller risk of injury than low chronic workload combined with several workload ratios (relative risk range from 0.3 to 0.7×/÷1.4 to 4.4; likelihood range=88-94%, likely). Considering acute and chronic workloads in isolation (ie, not as ratios) did not consistently predict injury risk. Conclusions Higher workloads can have either positive or negative influences on injury risk in elite rugby league players. Specifically, compared with players who have a low chronic workload, players with a high chronic workload are more resistant to injury with moderate-low through moderate-high (0.85-1.35) acute:chronic workload ratios and less resistant to injury when subjected to 'spikes' in acute workload, that is, very-high acute:chronic workload ratios ∼1.5.

Wearable microtechnology can accurately identify collision events during professional rugby league match-play

“…Given that the acute:chronic workload ratio derived from distance covered is associated with injury in rugby league players. 6 The present findings and the abovementioned studies provide evidence that researching contact-only workloads may be possible over acute and chronic periods, which could provide greater insight into collision injury risk.…”

The reliability of the submaximal version of the Yo-Yo intermittent recovery test in elite youth soccer

“…9 With the recent literature surrounding training load and injury risk in elite soccer, 14 a typical Yo-Yo IR1 benchmark of 2300 m 15 is a considerable distance, supplementary to the training load of a normal training week. As opposed to administering the Yo-Yo IR1, a more efficient, submaximal version has been utilised; the Yo-Yo Intermittent Recovery Test -submaximal (Yo-Yo IR1-sub).…”

Retrospective Analysis of Non-Contact ACL Injury Risk: A Case Series Review of Elite Female Athletes

“…Saw et al [13] found in their systematic review that athlete reported subjective information was highly sensitive to changes in athlete workload and physiological and psychological stress, so it is likely that these indings have some validity in demonstrating the athletes loading environment. Increases in acute training loads have been reported to signi icantly impact on the rate of injury [14]. This study has indicated that not on physical but cognitive loads should possibly be accounted for when assessing acute loading stress on the athlete.…”

“…The assessment and understanding of how these interactions create injury is beyond the scope of this case series and certainly requires further prospective study. What is apparent from this case series is ACL injury is unlikely to be related to a single factor, but a critical tipping factor might be loss of chronic training capacity or a perceived or actual increase in acute physical load [14].…”

“…The presence of another injury might disrupt training, decreasing the athletes work capacity and fatigue resistance, if the athlete then has perceived or an actual elevated level of fatigue, this may compound the situation further, with the greater the levels of fatigue the greater the potential for abhorrent movement patterns and injury risk. When returning an athlete following an injury which has disrupted training, consideration should be given not only to them being asymptomatic and being able to pass appropriate itness tests, but also that they have recovered their chronic training capacity, so they are able to cope with acute increases in load better [14].…”