You're revved up and ready to get fit. You can't wait to achieve a higher level of physical fitness — to feel better and have more energy to do all the things you enjoy. You're motivated, inspired and ready to get your body moving.

But jumping into a workout without preparing your body can lead to setbacks such as muscle strain and muscle soreness. To help your body adapt to the demands of repetitive movement, take time to warm up and stretch before you exercise. And don't forget to cool down afterward.

How it helps
Warming up prepares your body for aerobic exercise by increasing blood flow through your heart and lungs. This increase delivers more oxygen and sugar (glucose) to your muscles, which is necessary to get and keep you going. Your heart beats more rapidly and forcefully. You inhale and exhale more often. The temperature of your body slowly rises. Your muscles become warmer.

How you do it
Choose a warm-up activity that uses the same muscles you'll use during your workout. For example, if you're going to take a brisk 30-minute walk, walk slowly for five to 10 minutes to warm up.

Avoid sudden or aggressive movements during your warm-up. Doing this type of movement before your body is warmed up can cause injury.

How it helps
It's a good idea to stretch your major muscle groups after you warm up or before you cool down. Besides preparing your muscles for increased activity, stretching increases your flexibility and helps maximize the range of motion around your joints.

How you do it
If you only have time to stretch once during an exercise session, skip stretching after your warm-up and do it after your workout before you cool down. Your muscles will be warmer and more elastic.

How it helps
Taking time to cool down after your workout allows your heart, lungs and blood flow to return to normal gradually. This decreases strain on your heart and may help prevent muscle strain and soreness.

How you do it
For example, after a 30-minute session of brisk walking, cool down by slowing your walking pace for five to 10 minutes.

Avoid obstacles in your path to fitness by taking a few easy steps. Make time to warm up, stretch and cool down. Give your body the time it needs to adjust to the demands of your workout.