Steven J. Fleck

Value of resistance training for the reduction of sports injuries.

SummaryMany competitive and recreational athletes perform resistance training as a part of their conditioning programmes. Resistance training in addition to increasing muscular strength and hypertrophy may also aid in the prevention of injuries. Research indicates that resistance training promotes growth and/or increases in the strength of ligaments, tendons, tendon to bone and ligament to bone junction strength, joint cartilage and the connective tissue sheaths within muscle. Studies involving humans and animal models also demonstrate resistance training can cause increased bone mineral content and therefore may aid in prevention of skeletal injuries.Investigations to date suggest resistance training can aid in injury prevention. The incidence of various types of overuse injuries, such as swimmers shoulder and tennis elbow, may be reduced by the performance of sport and/or motion specific resistance training activities. Screening of athletes for agonist and antagonist muscle strength imbalances can be utilised to identify athletes possessing a predisposition for injury. Resistance training may then be performed to correct the imbalance and therefore reduce the incidence of injury.

Human torque velocity adaptations to sprint, endurance, or combined modes of training

We had groups of athletes perform sprint and endur ance run training independently or concurrently for 8 weeks to examine the voluntary in vivo mechanical responses to each type of training. Pre- and posttrain ing angle-specific peak torque during knee extension and flexion were determined at 0, 0.84, 1.65, 2.51, 3.35, 4.19, and 5.03 radian·sec-1 and normalized for lean body mass. Knee extension torque in the sprint- trained group increased across all test velocities, the endurance-trained group increased at 2.51, 3.34, 4.19, and 5.03 radian·sec,-1 and the group performing the combined training showed no change at any velocity. Knee flexion torque of the sprint and combined groups decreased at 0.84, 1.65, and 2.51 radian·sec.-1 Knee flexion torque in the sprint-trained group also decreased at 0 radian·sec-1 and in the combined group at 3.34 radian·sec.-1 Knee flexion torque in the endurance- trained group showed no change at any velocity of contraction. Mean knee flexion:extension ratios across the test velocities significantly decreased in the sprint- trained group. Knee extension endurance during 30 seconds of maximal contractions significantly increased in all groups. Only the sprint-trained group showed a significant increase in endurance of the knee flexors. These data suggest that changes in the voluntary in vivo mechanical characteristics of knee extensor and flexor skeletal muscles are specific to the type of run training performed.