Importance of frequency and intensity of strength training for work ability among physical therapists.

The aim of the study was to evaluate the association between frequency and intensity of strength training participation and work ability among physical therapists (PTs). The Work Ability Index questionnaire (WAI) and a questionnaire about participation in strength training during leisure time were administered to a sample of Spanish PTs. In addition, participants provided information on gender, age, body mass index, education, substance use, working experience and working hours per week. The odds for having excellent WAI (score 44-49) as a function of intensity or frequency of strength training participation were determined using binary logistic regression controlled for various confounders. Data from 981 PTs were analysed. High-intensity strength training (> 80% 1 RM) showed strong associations with excellent WAI (odds ratio = 9.7; 95% confidence interval, 2.9-31.6). In addition, performing strength training more than 3 times per week was associated with excellent WAI (odds ratio = 1.79; 95% confidence interval, 1.24-2.59), however, no significant associations were found with lower levels of frequency and intensities. High-intensity strength training 3 times per week is associated with excellent WAI among PTs. Training programs meeting these features may importantly contribute to maintain or improve WAI.