To accomplish a good cardio-vascular workout you should always remember to warm up first and cool down afterwards. This means gently stretching and moving your muscles to start off with. Suddenly moving into full exercise without building up first will cause problems such as stiffness and cramps. Ease yourself into it. Then after exercise, the cool down is basically gently moving the muscles and joints to stretch and relax, as your body returns to its normal pace.
Running
Make sure you have a good pair of running shoes. The technology put into these shoes nowadays is highly researched and designed to reduce shock to the feet, ankles, legs and back. So don't skimp on these - you get what you pay for.Before you start your run, be sure to warm up first. Start with a brisk walk ensuring you move your arms vigorously gradually breaking into a slow jog. It is better to run at a speed to which you can still converse. If you find yourself losing breath, slow your pace down until you've recovered. If you are a novice runner try running and walking, until you can hold your run for 15 minutes.
Now increase the length and time of your run by a couple of minutes every other time you hit the road or treadmill, until you can run for 30 minutes without stopping. Try to increase your run time by 10% each week, remember not to over do it and don’t forget to warm down at the end of each by slowing down gradually. When your run is complete stretch your legs for 30 seconds per muscle, hamstring, calf and thigh.