Summarize the following:
Weights are a good supplement to training because they strengthen the muscles and joints. Weight training also decreases injury risk. Research shows that runners who lift weights at least three times a week are stronger runners - they can run for longer and faster.  When lifting weights to augment your running, it's best to use a heavy weight that is enough to push your limits after 5 repetitions. Lifting lighter weights with high repetitions works to develop muscle size and endurance, but will not make you run faster. Fewer reps with heavier weight will help to develop faster, more powerful muscle contractions.  Strengthen and stretch your hip flexors. Studies have shown that doing hip-strengthening exercises can improve speed and agility. Try some basic exercises like the clamshell or sidestep. Make sure you are doing hip exercises at least 2-3 times a week.  Strengthen your hamstrings. It's important for runners to have strong and open hamstrings because fatigue in those muscles can cause injuries to your knees. Dead lifts, leg curls, and box jumps are good exercises to strengthen the back of your legs and avoid hurting your joints.  Strengthen your buttocks. Have a strong gluteus medius can help prevent lower-body injuries. Try taking the stairs instead of elevators during your daily routines.  Strengthen your core. The core is an area often forgotten by runners. To reduce inefficient motion while running, train and strengthen your core to provide stability. Static exercises like planks will give you the best core workout, rather than endless situps where its easy to fall into the bad habit of using momentum rather than strength. Cross-training involves doing another type of fitness activity that is not running. Cycling, swimming, skiing, using the elliptical machine are all ways to pump up your cardiovascular system without straining those muscles used in running. In fact, intense cross-training for an hour can elicit the same aerobic benefits as a run.  It's important do cross-training that involves lower-impact activity than running, which is a high impact activity. This will provide some relief to your joints on non-running days. Good activities include swimming, cycling, and rowing, among others.  There is a basic formula for cross-training: Do 60 minutes at or above 70 percent of your maximum heart rate. This will be the equivalent of a 8km run. Incorporate cross-training into your workout a couple of times a week (on days when you don't run). After exercising, massage your leg muscles with a foam roller. This post-workout exercise will increase flexibility and range of motion in the knees. Rolling will also work to break down scar tissue.

Summary:
Do weight and strength training. Cross train. Foam roll.