Gabe Mirkin, M.D.
Warming up before you exercise helps to prevent injuries
and lets you jump higher, run faster, lift heavier or throw further.
Your warm-up should involve the same muscles and motions you
plan to use in your sport. For example, before you start to run
very fast, do a series of runs of gradually-increasing intensity to
increase the circulation of blood to the muscles you will be using.
Muscles are made up of millions of individual fibers, just
like a rope made from many threads. When you start to exercise
at a very slow pace, you increase the blood flow to muscle fibers,
increase their temperature, and bring in more oxygen, so the
muscles are more pliable and resistant to injury. When you
contract a muscle for the first time, you use less than one percent
of your muscle fibers. The second time you bring in more fibers,
and you keep on increasing the number of muscle fibers used in
each contraction for several minutes of using that muscle. It’s
called recruitment. When you are able to contract more muscle
fibers, there is less force on each individual fiber to help protect
them from injury. Usually you are warmed up when you start to
sweat.
The same principle applies to your heart. Angina is a
condition in which the blood vessels leading to the heart are
partially blocked so the person has no pain at rest, but during
exercise, the blocked arteries don't permit enough blood to get
through to the heart muscles, causing pain. If people with angina
exercise very slowly before they pick up the pace, they are able
to exercise longer and more intensely before they felt heart pain.
Always check with your doctor if you feel any heart pain during
exercise.
Competitive athletes in sports requiring speed and
endurance perform better after they warm up with increasing
intensity. Warming up slowly does not increase the maximum
amount of oxygen that you can bring to muscles that you need
during competition. If you are a runner, skier, cyclist, or an
athlete in any sport that requires endurance, warm up at a
gradually increasing pace. Use a series of increasingly intense
repetitions of 10 to 30 seconds duration, with short recoveries,
until you are near your maximum pace. This type of warm-up
increases endurance because intensity increases the maximum
amount of oxygen that you can bring to your muscles, as you
continue to compete, and lets your muscles contract with greater
force as you begin to fatigue. You will then be able to bring in
more oxygen to your muscles than you could have done without
the intense warm-up.
November 20, 2005