Mileage. Drastic increases in your weekly mileage will increase your chances for injury. This includes jumping back to your old training routine after an extended break. The rule of thumb for this is to keep your mileage increases below 10% per month. So if you’re running 10 miles one week then following week should be 11 miles and no more.
Resting. Once every 3 weeks your body could benefit from a reduction in running mileage. Rather than adding 10% to your distance remove 30%. This will give your joints and muscles time to recover.
Warm up. Take about 1 mile to warm up before you actually start running at your running pace. The time spent warming up reduces the stress on your cardio-vascular system because it takes time for your body to adjust the flow of blood to the vital muscles needed for running.
Hills and speed work. Running up hills builds strength necessary for speed work but with less stress on the body. Before you start sprinting around the track you should build up strength by doing hill work once per week for 3 or 4 weeks.
Running Fast. Running fast uses some different muscles than a jog, and increases the stresses on your joints. To improve your speed you should do speed work no more than once per week with a good warm up and cool down.
Stretching. Stretching your muscles just after you finish your run will reduce the strain on your muscles. After an intense run you should do light stretching, while after an easy run it is better to do more stretching.
Stride. Rather than increase the stride distance to run faster focus on moving your feet quicker. Lengthening your stride increases the impact to your joints and muscles. You’ll see the same speed increase with less impact by maintaining your stride while improving your foot turnover rate.