One of the key things to do to avoid injury as you run, jog, or walk is to stretch and strengthen your muscles before and after you exercise. Light stretching will loosen your muscles and help you warm up. Stretching after will help remove the lactate from your muscles that was generated while you ran. In addition, stretching will help strengthen your muscles, enabling you to run better and helping you avoid injury.
A word of caution is in order, however. Any activity that causes muscle movement causes stress in your body, and too much stress is the cause of injury. Thus, if you aren't careful, doing stretches can contribute to injury. I've found that the keys to safe stretching are (a) experience no pain while you stretch, (b) do gentle, slow muscle movements when you stretch, and (c) don't rock your body back and forth or jump up and down. If you feel pain, back off and don't pull your muscles as much .
Use Anti-Injury Exercises
Dr. Weisenfeld in The Runners' Repair Manual ( Amazon ) has a chapter on "The Best Anti-Injury Exercises I've Ever Found".Let's take a look at what he says:
I'm going to let you in on a secret that could cut my practice by a third. If you do the right exercises and do them regularly, you can avoid most injuries. On the other hand, if you run and don't exercise, you're almost sure to be injured. It's that simple. Every run you take causes microscopic tears in the muscles, and when these tiny tears repair themselves, they form scar tissue. This scar tissue cannot be flexed or stretched. So every time you run, your muscles are getting tighter and tighter--and less able to stretch. A tight, inflexible muscle is a setup for injury. It can't take the shocks and jolts of running or the constant pulling of a long runner's stride. A tight muscle is one that's ready to be injured. And, along with these tight muscles, other muscles in your body are very tight while nearby muscles are relatively very soft. That's another setup for injury. So save yourself yourself some pain and money. Learn a basic group of exercises like the warm-up I'll give you here, or any good, well-balanced set of exercises.-- The Runners' Repair Manual, copyright 1980, chapter 3, pp. 33-34
He describes (with pictures) a set of stretches that will help keep your muscles lose, strong, and injury-free. I heartily recommend that you get his book and follow it in your running!
We all have our own way of stretching, and this is what I do (most are from Weisenfeld). I've posted pictures illustrating most of these stretches.
Three variations of wall pushups for calf and soleus
Foot on stair knee up for hamstring
Bent leg for quads
Knee press for hamstring and lower back
Knee lifts for lower back and abdominal
A variation of knee lifts in which one knee is bent and my head is raised up to touch the knee with my nose, the other leg is on the ground with knee bent
Furniture lift for shins
Leg raised in air for quads
A variation of flying in which my arms trace a horizontal figure-8 to get both sides of my brain working
Situps from a Runners' World article (see below)
Push ups (crosstraining)
After finishing my run, I walk a few hundred feet to cool down, and then I do the wall pushups, foot on stair, bent leg, ITB, leg lift, flying, and the variation of flying.
Situps Can Kill Your Back
Lower back pain is one of the common ailments that afflict runners. After I had been running for several years, I started having mild lower back pain. Coincidentally, Runners' World published an article on lower back pain about a month after I started having pains. That article suggested doing situps to strengthen ones stomach and thus strengthen ones back muscles; you can't have a strong back if you have a flabby stomach.
To me, doing situps meant doing them the "army" way, but the method suggested by Runners' World was different. If you do situps the "army" way, you keep your arms behind your head and place your head and shoulders on the ground each cycle. Your back muscles have to exert great effort to raise your head and shoulders off the ground, and unless your back is in good condition, that effort can injure your back.
In contrast, the Runners' World method for situps keeps your head and shoulders off the ground and to keep your arms stretched out in front of you, parallel to the floor, as if you were reaching for your toes. You rock your body back and forth. Your knees are bent in both positions. How far you bend depends on your condition, but keep your head and shoulders off the ground). When I tried this method, I found that could raise my body up and down with no noticeable strain on my back muscles. After about a month of doing sit ups this way, my lower back pain was gone!
Arms parallel to ground, knees bent
Head & shoulders off the ground, knees bent
I do 30 situps before I run, and after years of running, my back is in fine shape. I've also gained a beneficial side effect from doing the situps. Most of the time when I finish the situps, I feel great and am anxious to hit the roads. Some times, however, I feel tired after completing the situps, and I know that my body is tired and that I'd better take a slower and perhaps shorter run. My situps are a good indicator of my body condition.
For a stronger back, do the following lower-back stretches
Lie prone to relax back muscles
Keep head flat, pull knees towards chest
Touch knee to nose if possible
Touch other knee to nose if possible
Your Knees are for Running not for Hurting
Knee pain is another common problem with runners. Runners doing hills are especially susceptible to knee problems.Before each run, I do several repetitions of the foot press and inner thighs stretches that are described by Dr. Weisenfeld in The Runners' Repair Manual, and I've never had knee injuries, even after 17 years of running in hilly New England. Here is Dr. Weisenfeld's description of how to do those exercises.
Foot Press. Strengthens quadriceps (thigh) muscles, for treatment/prevention of runner's knee. Strengthens anterior leg muscles, for treatment of shin splints. Can be done lying down or sitting in a chair. Put your right foot on top of your left foot. Your lower foot tries to pull toward your body as your upper foot pushes it away from the body. Hold for ten seconds. Now switch feet--put the left foot on top of the right foot, and push/pull for ten seconds. This equals one set. Do five sets.-- The Runners' Repair Manual, copyright 1980, chapter 4, pp. 38
Foot Press: Isometrics with toes
Inner and Outer Thighs. The turned-out position strengthens the outer thigh muscles--for treatment/prevention of runner's knee. The turned-in position strengthens the inner thigh muscles--for treatment/prevention of groin pull. Can be done lying down or sitting in a chair. Stretch both legs out--knees straight, feet flexed (Toes pointed toward knees.) Tighten your thigh muscles. Now, turn your feet out as far as you can and hold ten seconds. Then turn your feet in as far as you can and hold ten seconds. Keep thigh muscles tight throughout exercise.-- The Runners' Repair Manual, copyright 1980, chapter 4, pp. 38 -39