August 24, 2006
Athletes can warm up with infrared light: study
NEW YORK (Reuters Health) - Forget tedious warm-up
exercises. Athletes may be able to ready their muscles using
pulses of infrared light, a study suggests.
In a study of 24 young adults, Japanese researchers found
that a device that emits near-infrared light warmed up the
shoulder muscles better than standard warm-up exercise. [
athlete, this so-called "deep thermal therapy" could offer an
exertion-free alternative, according to the study authors, led
by Dr. Shinichi Demura of Kanazawa University.
The idea of using a "passive" warm-up before competition is
not new. Hot pads and steamy showers are other ways of warming
the muscles and improving range of motion in the joints, Demura
and colleagues note in their report in the Clinical Journal of
However, they add, irradiation with polarized near-infrared
light can penetrate to deeper muscles and, theoretically,
provide a more thorough warm-up. The technique has already been
used to treat pain from joint and muscle injuries and from
For the current study, Demura's team had 24 young men and
women go through each of three warm-ups, then tested the
effects of each one on participants' shoulder joint
In one condition, participants rode a stationary bike for
10 minutes to warm up their whole body; in another, they had
their shoulder and back muscles irradiated with the
near-infrared light-therapy device; in the third, they received
"placebo" irradiation, in which the light pulses were set at a
very low intensity.
According to the article, the device used to deliver
polarized near-infrared light was the Super Lizer made by Tokyo
Medical Laboratory, which "is often used in medical studies or
Overall, the researchers found, both exercise and the light
therapy improved participants' range of motion in the shoulder,
but the latter worked slightly better. They believe the therapy
may improve blood flow to the deeper layers of muscle that act
on the shoulder joint.
More studies should look into the effects of combining such
light therapy with warm-up exercises, according to Demura's
team. For competitive athletes, they note, a break from the
standard warm-up could save some needed energy.
SOURCE: Clinical Journal of Sports Medicine, July 2006.