Give each body part attention about three times a week. Train the muscle groups most in need of conditioning that will be of greatest benefit to running. For example, if you followed a body builder s weight training routine you will probably find minimal, if any improvement, in running performance. Quite possibly, running performance would diminish. Ensure muscle balance by training antagonists as well as agonist muscle groups.
Antagonist muscles are the muscle or muscles that can slow down or stop a movement.
Antagonist muscles assist in joint stabilization. Provide a progressive overload stimulus. In other words, you must progressively place greater than normal demands on the exercising musculature for desired increases in strength to occur. Work the muscles throughout their full range of movement so that strength gains occur in the full range of motion. Failure to do so could result in injury.