Physical, psychosocial and dual-career loads as risk factors for injuries and illnesses in elite handball players: a 45-week longitudinal cohort study

Kristina Drole^1*Armin Paravlic^1,2Kathrin Steffen^3,4Mojca Doupona¹

• ¹Faculty of Sport, University of Ljubljana, Ljubljana, Slovenia
• ²Masarykova univerzita Fakulta sportovnich studii, Brno, Czechia
• ³Norwegian National Unit for sensory loss and mental health, Oslo universitetssykehus, Oslo, Norway
• ⁴Oslo Sports Trauma Research Center, Norges idrettshogskole Institutt for idrettsmedisinske fag, Oslo, Norway

Abstract Introduction: While training and competition load are well-documented risk factors for injury, the influence of dual-career loads, life stressors and overall load on both injury and illness remain less clear. The aim of this study was to investigate whether injury/illness occurrence is influenced by the training, competition, academic and work loads, as well as the overall load (sum of academic/work, training and competition loads) and life events in elite male handball players. Methods: In this 45-week prospective cohort study, 189 elite male handball players weekly reported their load across training, competition, academic, and work domains. We derived a "overall load" variable as the sum of training, competition, academic and work hours. Health problems, including acute noncontact/overuse injuries and illnesses, were recorded using OSTRC-H2-SLO, while psychosocial load was assessed using the LESCA questionnaire. Multivariate logistic regression and non-parametric tests were used to identify risk factors and group differences. Results: Injured athletes reported significantly higher training (MD=2.6 h; p < 0.001), and overall loads (MD = 2.9 h; p = 0.042), but lower academic loads (MD=2.5 h; p = 0.001) than non-injured athletes. Similarly, ill athletes had higher training load (MD=1.55 h; p = 0.026) and competition loads (MD=0.23 h; p < 0.001) but lower academic loads (MD=2.24 h; p = 0.001). Training load emerged as a significant predictor of both injury (OR=1.33) and illness (OR=1.23), and competition load strongly predicted illness (OR=37.00). Academic and work loads were not significant predictors. Higher LESCA total scores were associated with increased injury (p=0.041) and illness risk (p=0.017), while negative scores were associated with increased illness risk (p=0.012). Discussion: Training and competition loads are key modifiable risk factors for injury and illness, while dual career might serve as a protective factor. While negative life events appear to be associated with illness, the overall volume of life changes—regardless of whether they are positive or negative—emerges as a significant factor in injury risk. Our results support the development of an integrated biopsychosocial model of athlete's health, where sports-and non-sports-related loads, together with life events shape an athlete's vulnerability to injury and illness.