Before you jump on the treadmill or hit the running trails, think about doing a short warmup first. And try following your workout with a quick cool-down session. A warmup and cool-down may add a few minutes to your exercise routine. But they might also lower stress on the heart and other muscles.

Warmups and cool-downs generally mean doing your activity at a slower pace and lowered intensity.

Warming up helps get the body ready for aerobic activity. A warmup slowly warms up the heart and blood vessel, also called cardiovascular, system. It does this by raising the body temperature and increasing blood flow to muscles. When you warm up, it also may help lower muscle soreness and lessen injury risk.

Cooling down after your workout lets the heart rate and blood pressure slowly recover to preexercise levels. It may be most important for competitive endurance athletes, such as marathoners, to cool down to help control blood flow. Cooling down doesn't seem to help reduce muscle stiffness and soreness after exercise, but more research is needed.

There's debate about whether warming up and cooling down can prevent injuries. But proper warmups and cool-downs pose little risk. And they seem to give the heart and blood vessels a chance to ease into — and out of — an exercise session. So if you have the time, try adding a warmup and cool-down to your workout routine.

Warm up right before you plan to start your workout. In general, warm up by focusing first on large muscle groups, such as the hamstrings. Then you can do exercises more specific to your sport or activity, if needed.

Start by doing the activity and movement patterns of your chosen exercise. But go at a low, slow pace that slowly builds in speed and intensity. This is called a dynamic warmup. A warmup may cause mild sweating. But a warmup generally won't leave you tired.

Here are some examples of warm-up activities:

• To warm up for a brisk walk, walk slowly for 5 to 10 minutes.
• To warm up for a run, walk briskly for 5 to 10 minutes.
• To warm up for swimming, swim slowly at first. Then pick up the speed as you're able.

Cooling down is similar to warming up. You generally keep doing your workout session for five minutes or so. But you go at a slower pace and lower intensity.

Try these ideas for cool-down activities:

• To cool down after a brisk walk, walk slowly for 5 to 10 minutes.
• To cool down after a run, walk briskly for 5 to 10 minutes.
• To cool down after swimming, swim laps slowly for 5 to 10 minutes.

If you do stretching exercises as part of your workout routine, it's best to do them after the warm-up or cool-down phase. Then the muscles are warm when you stretch.

Stretching can improve flexibility and range of motion about a joint. Doing stretches also may help improve your performance in some activities by allowing the joints to move through their full range of motion. But studies haven't regularly shown that stretching helps prevent muscle soreness or injury.

Finding time for regular aerobic workouts — plus warming up and cooling down — can be hard. But with a little creativity, you can probably fit it all in. For example, you can walk to and from the gym for your warmup and cool-down.