No association between perceived exertion and session duration with hamstring injury occurrence in professional football

Abstract

Training and competition loads have emerged as modifiable composite risk factors of non‐contact injury. Hamstring strains are the most common injuries in football with substantial burden on the individual player and club. Nevertheless, robust evidence of a consistent load‐hamstring injury relationship in professional football is lacking. Using available data from the Qatar Stars League over three competitive seasons, this study investigated the separate and combined effects of perceived exertion and session duration on hamstring injury occurrence in a sample of 30 outfield football players. Load variables were calculated into 7‐day, 14‐day, 21‐day, 28‐day periods of data, and week‐to‐week changes for average ratings of perceived exertion (RPE; au) score and session‐RPE (s‐RPE; session‐duration × score), plus the cumulative training and match minutes and s‐RPE, respectively. Conditional logistic regression models estimated load‐injury relationships per 2‐within‐subject standard deviation increments in each candidate variable. Associations were declared practically important based on the location of the confidence interval in relation to thresholds of 0.90 and 1.11 defining small beneficial and harmful effects, respectively. The uncertainty for the corrected odds ratios show that typically high within‐subject increments in each candidate variable were not practically important for training‐ and match‐related hamstring injury (95% confidence intervals range: 0.85 to 1.16). We found limited exploratory evidence regarding the value of perceived exertion and session duration as etiological factors of hamstring injury in Middle‐East professional football. Monitoring remains valuable to inform player load management strategies, but our exploratory findings suggest its role for type‐specific injury risk determination appears empirically unsupported.

Global Positioning System–Derived Workload Metrics and Injury Risk in Team-Based Field Sports: A Systematic Review

“…Other statistical variances that require attention in this body of research moving forward include appropriate sample-size calculations for the number of predictors that researchers intend to use in their models. 44 Using pseudo-R 2 statistics, Lolli et al, 45 in their 2019 paper on perceived exertion, session duration, and hamstrings injury, determined that sample sizes of 329, 583, or 1166 players were needed for 1, 5, or 10 load-related predictors, respectively. None of the studies in this review came close to those sample sizes.…”

Player Monitoring in Professional Soccer: Spikes in Acute:Chronic Workload Are Dissociated From Injury Occurrence

“…Studies have examined the association between external/internal training load and injury in professional soccer players, with highly inconsistent findings ranging from significant interrelationships to clear disassociations (Hulin et al, 2016;Bowen et al, 2017Bowen et al, , 2020Malone et al, 2017;Fanchini et al, 2018;Lolli et al, 2019). Using the external load to describe the relationships between ACWR and injury risk, Hulin et al (2016) found that the ratio of acute to chronic workloads (absolute total distance) predicted injuries in elite rugby players.…”

“…Contrary to the aforementioned findings, recent articles using internal load indicators suggest a poor interrelationship between the ACWR and injury incidence (Fanchini et al, 2018;Lolli et al, 2019). In professional soccer players, increased ACWRs were associated with poor predictive validity in identifying players who will suffer a future injury (Fanchini et al, 2018), and the relationships between match and training loads with hamstring injuries showed no associations between ACWRs and injury occurrence in professional football (Lolli et al, 2019).…”

“…Limitations such as integrating data from different tracking systems (GPS during training vs. semiautomatic cameras for games), international breaks without data from national teams or using systems that differ from those used in the club, or predicting data when nothing is available, make the application of this model very difficult in professional soccer (Buchheit, 2017). While session-RPE may offer some advantages for data collection compared to external load in the elite soccer context, recent articles using internal load indicators suggest a poor interrelationship between the ACWR and injury incidence (Fanchini et al, 2018;Lolli et al, 2019). The present results did not find any association between spikes in ACWR quantified from GPS with injury incidence during the 10-microcycle seasonal period.…”

“…Recent studies have proposed external load parameters such as total distance (TD) (Hulin et al, 2016), high speed and sprint (Malone et al, 2017), decelerations (Bowen et al, 2020) and accelerations (Bowen et al, 2017) as strong indicators of overall and non-contact injury risk, identifying ACWR values >1.5 as dangerous acute spike workloads with a high injury risk (Gabbett, 2016). Contrary to the aforementioned findings, recent articles using internal load indicators suggest a poor interrelationship between the ACWR and injury incidence (Fanchini et al, 2018;Lolli et al, 2019). In professional soccer players, increased ACWRs were associated with poor predictive validity in identifying players who will suffer a future injury (Fanchini et al, 2018), and the relationships between match and training loads with hamstring injuries showed no associations between ACWRs and injury occurrence in professional football (Lolli et al, 2019).…”