Comparing the Acute Effects of a Session of Isometric Strength Training with Heavy Resistance Training on Neuromuscular FunctionOACSCD

Purpose This study compared the acute effects of a session of isometric strength training(ISO)with heavy resistance training(HRT)training on 20-m sprint,countermovement jump(CMJ)and isometric mid-thigh pull(IMTP)performance.Methods Ten resistance-trained athletes(age:26.7±6.2 years,body mass:71.5±16.2 kg,height:1.68±0.10 m)performed baseline measures for 20-m sprint,CMJ and IMTP prior to either an ISO or HRT session.During both training sessions,participants performed back squats,Romanian deadlift and split squat.Post-test performances were measured 5 min and 24 h after each training session.Participants returned a week later to perform the other training session.Results A significant time×condition effect was found for 20-m sprint time(P=0.007)and IMTP peak force(P=0.003).Main time effect was observed for 20-m sprint(P<0.001),CMJ height(P<0.001)and IMTP peak force(P<0.001).HRT resulted in a greater increase in sprint time at 5 min(0.17±0.12 vs.0.06±0.05 s,P=0.013,g=1.15)and 24 h(0.01±0.09 vs.0.00±0.05 s,P=0.004,g=1.32)post-training as compared to ISO.Similarly,HRT resulted in a significantly larger reduction in IMTP peak force than ISO at both 5 min(-363.3±248.8 vs.-98.9±230.3 N,P=0.024,g=1.06)and 24 h(-289.2±256.2 vs.37.9±177.8 N,P=0.004,g=1.42)post-training.Total impulses generated during each exercise were greater during ISO than HRT(P<0.001–0.006).Rating of perceived recovery post 24 h was higher in ISO than HRT(P=0.002).Conclusion The above results indicated that acute HRT led to a greater reduction in sprinting strength performance and lower perceived recovery post-24 h than ISO.