Take this familiar scenario: You are walking casually to the bus stop and then realize the bus is pulling up and you are still quite a length behind. The bus begins to pull away from the curb, and you still have 100 yards to go. In a split second, you turn on the juice and dash toward the bus. Your arms are pumping, your legs are striding and your lungs are blowing like a blacksmith’s bellows.

Ah, success. You make it on board, and with a sigh of relief you plop into the chair. Immediately, you feel a stitch in your ribs, and the back of your legs tighten into a cord. Sitting is uncomfortable because your bottom is cramping up, and the air-conditioned bus feels overly hot because your skin is a little clammy.

These ill effects result from taking a "cold" body and making it do what only a warm body should. A body at rest is ill prepared to deliver high levels of work. The heart beats slowly, the lungs take in a quarter of their maximum capacity, the arteries are constricted and the skeletal muscles fire only a minimum of their total strength.

A deliberate and well-paced warm-up primes these systems to deliver by slowly increasing the load placed on them. Conversely, cooling down takes these elevated systems gradually back to rest, allowing enough time for heat dissipation and lactic acid processing and removal — all-important in preventing after-exertion cramping.

A good warm-up complements the activity and approaches the lowest limit of the highest intensity you plan to perform. The cool-down, in turn, should allow enough time for the heart rate to drop 30 to 40 beats from the highest level achieved. In other words, you should feel the "pounding" in your chest subside to a dull thumping instead.

Here are some tips to ensure a proper warm-up and cool-down sequence:

Warming up

» Begin taking deeper breaths from the bottom of your diaphragm and releasing when the lungs feel full. Do not rush. Be sure to time your movements with your breathing.

» Take your body through long, deliberate motions. For example, if you are jogging, start the session by taking overly long strides that coincide with the deeper breathing. Take time to feel the legs extend to their maximum length and the glutes contract to their fullest. In the case of resistance training, start with a light set and focus on proper technique to ensure recruitment of the proper motor units.

» A typical warm-up should last at least five to 10 minutes.

Cooling Down

» Do not sit down.

» In the case of jogging, slow the pace to a brisk walk for a few strides and then walk at a resting pace for a minimum of five minutes or until the chest feels looser.

» If you are lifting weights, cool down with the opposite motion in which you were lifting. This means that if you were working on the bench press, for example, end your session with a hanging stretch from the pull-up bar.

Essentially, gradual increase and decrease of intensity is the key. The body dislikes sudden upheavals in its homeostasis. Working out hard is something your body needs; just make sure it is ready for the task.

Reggie Palma is an exercise physiologist and personal trainer. He has a fourth-degree black belt in the Filipino martial art kali. He can be reached at fitnessatyourdoor@mac.com or 392-2314.