The effects of training based on Nordic hamstring and sprint exercises on measures of physical fitness and hamstring injury prevention in U19 male soccer players.

This study analysed the effects of a training program based on Nordic hamstring and sprint exercises on physical performance and hamstring injuries in young male soccer players. Forty-nine U19 players were randomly assigned to a control (CG; n = 26) or experimental group (EG; n = 23). Linear sprint and with change of direction (COD) were assessed before and after a 14-week training period. Hamstring injuries were collected during the intervention period. Between-groups analysis revealed differences in linear sprint performance (p = 0.012-0.001) in favour of the EG. Pre-to-post performance increased significantly in the EG for 20 m (effect size [ES] = -0.56) and 30 m (ES = -0.62) sprints, but a significant reduction in some COD parameters was observed (ES = 0.45-0.57). In CG, only a significant reduction in COD with dominant leg was found (ES = 0.63). Significant differences in injury burden in favour of the EG was reported such as (27.87 [CG] vs. 3.82 [EG] absence days/1000 h of exposure, rate ratio = 7.30, 95% CI 3.34-15.99). While injury incidence was not different between the EG and CG. These findings suggest that the training program implemented can improve sprint performance and reduce injury burden.

Effects of body mass-based resistance training on measures of physical fitness and musculotendinous injury incidence and burden in U16 male soccer players.

This study examined the effects of body mass-based resistance training (bmRT) on selected measures of physical fitness and injury incidence and burden in soccer players. Forty-six U16 male soccer players were randomly assigned to an control (CG; n = 26) or experimental group (EG; n = 20) Countermovement jump (CMJ), change of direction (CoD) (i.e., 20 m with one CoD), and linear sprint over 30 m were assessed before and after a 15-weeks training. Any type of musculotendinous injury that occurred throughout the intervention period was recorded. Between-group difference was noted at post-test for CMJ (p = 0.008). Pre-to-post training values increased in the EG (effect size [ES] = 1.01) while in the CG no pre-to-post changes were detected (ES = 0.27). No between-group differences at post-test were observed for sprint and CoD tests. Differences in injury burden were reported (33.28 [CG] vs. 9.55 [EG] absence days/1,000 hours exposure, rate ratio = 3.49, 95% CI 2.03-6.00, p < 0.001), but not in injury incidence. A bmRT programis suitable for improving jumping height but not linear and CoD speed performance. Additionally, bmRT may reduce injury burden, and therefore, the severity of musculotendinous injuries in U16 male soccer players.

The effects of jump training on measures of physical performance, lower extremities injury incidence and burden in highly trained male soccer players.

This study aimed to analyse the effects of a 16-week jump training program on the physical performance and lower extremities injury profile in semi-professional male soccer players. Participants were randomly assigned to the control group (CG; n = 13; age = 21.7 ± 3.6 years) or the experimental group (EG; n = 10; age = 22.3 ± 3.5 years). Countermovement jump (CMJ) height (cm), 30 m linear sprint time (s) with split times at 10 m and 20 m distances, and change of direction speed (CODS; 10 + 10 m with 90° turn) time (s) with turns using the dominant or non-dominant leg, were assessed before and after the intervention. Lower extremity injuries sustained throughout the intervention period were collected. Significant within-group improvements were found in EG in CMJ (p = 0.01; effect size [ES] = 1.03; large). Additionally, between-group difference after intervention was found in CMJ (F = 4.42; p = 0.013) in favour of EG. Injury burden was 194.86 (CG) vs 71.37 (EG) days of absence/1,000 h (RR = 2.73; 95% CI 2.10-3.54; p < 0.001). No other significant within-group or between-group differences were found. In conclusion, compared to regular soccer training, jump training was effective to improve jumping ability and burden in soccer players.