915 EP002 – Offseason strength training increases strength levels but decreases hamstring/quad ratio in professional soccer players

Off-season in soccer is usually determined with partial or complete training cessation, decreases in force production and consequent increases in injury risk. To counteract this, offseason-strength training is regularly prescribed. To examine the effects of low volume offseason strength training on lower body strength and hamstring/quads ratio in elite soccer players. We conducted four weeks longitudinal, time-series study design. The study was carried out during midseason break of the 2022/2023 season. All participants were members of Serbia first division soccer team,regularly ranked within first four teams in league for the past 5 years. All the players participated in at least 6 training sessions per week in the last 12 weeks of season Fourteen male professional soccer players (27.14±5.90 yrs., 180.82±7.49 cm, 76.59±7.02kg) participated in the study. Interventions The players were subjected to lower body, low volume strength training (4 exercises, 2 sets, around 80% of 1M), 2 times per week for 4 weeks. Isokinetic strength tests (60 degrees/s) were performed before and after 4 week study period, with quads and hamstring Peak force for left and right leg determined. There was significant difference for both leg quads (L: 45.86 ± 6.53 kg vs 48.47 ± 8.73 kg; R: 44.08 ± 5.70 kg vs 47.40 ± 6.86 kg Pre vs Post; p< 0,05) and leg hamstring strength (L: 33.60 ± 4.52 kg vs 34.85 ±4.50 kg; R: 33.02 ± 5.29 kg vs 34.341 ± 4.80 kg Pre vs Post; p< 0,05). Interestingly significant decrease in H/Q ratio was reported for both legs ( R: 75.31 ± 0.1% vs 73.12 ± 0.1 ; L: 73.21 ±0.1 vs 71.1 ± 0.1 kg Pre vs Post; p>0,05). Low -volume strength training during offseason increased lower body strength but also injury risk, thru decreases in H/Q ratio.