Strength training should be an important component of a serious runner's workout. Building muscular strength, particularly in the legs, corrects muscle imbalances and helps create power. A regular strength-training program can also reduce the risk of injuries. You can weight-train during the off-season or year-around. If you are serious about running fast, however, it will probably be necessary to back off weight training during the competition season to prevent overtraining.
Develop a schedule that works for you. A break between workouts gives the body time to recover and may reduce the risk of overuse injuries and the chances of overtraining. Chris Carmichael, in "Outside Magazine," recommends training in blocks. One example of a training block that allows you to build leg muscles for speed is to weight-train two days, rest one day and then do speed workouts for three days. This is just one example; the important thing is to work out a schedule that works for you, when you can make it to the gym and when you can run.
Integrate hill workouts into your running. Lifting weights is not the only way to build leg muscles. Hill workouts increase leg strength and power. "Running Times" recommends one or two hill workouts each week as part of a strengthening program.
Use big lifts, such as squats and deadlifts, that work multiple body parts, as the main component of the leg-building program. Complete the exercises at a weight that allows you to do six to 12 repetitions.
Follow up all workouts with a stretching routine. Increasing muscle mass will not improve performance if it comes at the expense of flexibility. It is important to stretch after each workout to maintain a full range of motion through the core, hips and knees.
Train your brain to use new muscle through short, fast repeats. Several times a week, run short, fast repeats. Ten repeats, about 20 seconds long, run at about 90 percent of your maximum speed, will train the brain and nervous system to recruit the leg muscles. Warm up thoroughly before you begin this workout and recover fully between each sprint. This is a mind-body workout, not a cardiovascular one.