Background The Covid-19 pandemic caused a forced lockdown longer than the normal annual season break in Iranian football leagues. Return to football after such a long break without organized team training might increase the rate of injuries.

Objective To investigate the effectiveness of a home-based injury prevention program (IPP) on reducing injuries in semi-professional football players.

Design Prospective cohort study based on a randomized controlled trial.

Setting Iranian semi-professional male football players.

Participants A total of 178 players from 11 clubs participated in study. From the total of 178 subjects (90 subjects in the intervention group and 88 in control group), 10 subjects dropped out due to a positive Covid-19 test, leaving 87 subjects in the intervention group and 81 in the control group for the final analysis.

Interventions The IPP consisted of 8 weeks home training program with focus on the most common injury locations. The IPP was addressed strength, mobility and balance via neuromuscular and body-weight training with no equipment.

Main Outcome Measurements Non-contact injury rate in the remaining season(8 weeks), trainng and competition exposure, compliance with the IPP.

Results Player compliance with the IPP was very good (94%). Exposure data were comparable between groups. Pooled estimates for total (training and match) incidence per 1000 h was 7.8 for the intervention group and 15.9 for control group. A lower proportion of players in the intervention group experienced injuries (29% [27 of 87]) compared with the control group (75% [61 of 81]; relative risk [RR], 0.41; 95% confidence interval [CI], 0.29–0.61; p<0.001).

Conclusions A home-based, unsupervised IPP was shown to be effective in reducing the number of injuries in semi-professional male football players after the Covid-19 break. This indicates that going back to training and match play without accompanying IPP cannot be regarded optimal.