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

BACKGROUND: 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.

METHODS: 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.

RESULTS: 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).

CONCLUSIONS: 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.