Adaptations to Strength Training

Muscle Fiber Adaptation
The most obvious effect of weight training is the increase in muscle size also called hypertrophy. Hypertrophy is the result of an increased amount of actin, myosin, and related proteins. High resistance with low repititions will lead to hypertrophy in males. Usually females do not have enough testosterone for significant hypertrophy. Weight training leads to increased fiber size and an uncreased number of sarcomes in trained fibers.

Corrective Fiber Adaptation
Weight training also makes changes to the body's connetive tissues (cartilage, tendons, and ligaments). Connective tissues get stronger which leads to overall strength gain.

Increased Nervous System Activity
Weight training stimulates motor units that were previously inactive, when a person begins a weight program. They will see gains in strength by three weeks, but no hypertrophy. This is because of the recruitment of motor units that were inactive previously.

Decreases Nervous Inhibition
Strength training raises the force threshold where the golgi tendon is stimulated.