The effect of high speed strength training with heavy and low workloads on neuromuscular function and maximal concentric quadriceps strength.

Abstract

Dynamic strength training has been widely used to increase the ability of skeletal muscle to produce muscle force. Manipulating resistance training program variables has been commonly used as a tool to optimize maximum strength. This study examined the effects of 12 weeks of high-speed strength training with low and heavy workloads on muscle strength and neuromuscular function of quadriceps muscle. Thirty male subjects (age, mean±SD, 20.6±2.6 yr, body mass 70.4±12.9 kg, height 1.76±0.09 m) with no history of knee injury or trauma participated to the study. Subjects were randomly divided into two training groups, low workload training (40% 1RM) and heavy workload training (80% 1RM). One repetition of maximum leg-press measured before and after 12 weeks training. Moreover, surface electromyograpic signals were recorded from vastus medialis and lateralis muscle during one repetition of maximum leg-press before and after 12 weeks training. High speed training with heavy workload-low repetition resulted in a greater increase (41.8%±4.3) in maximal concentric quadriceps strength compared with high speed training with low workloads-high repetition (23.3%±2.7; F=3.8, P<0.035). Average rectified value of EMG after 12 weeks high speed training with heavy workload- low repetition was significantly larger than those observed after high speed training with low workload- high repetition (F=5.5, P<0.039). The result indicates that, high speed movement combined with heavy workload is an effective stimulus for neural adaptations to training, which in turn result in greater improvement in muscle strength.