DOCTOR'S VIEWS ARCHIVE
Circadian Rhythms & Athletics
NFL Odds
STANFORD, CA - More and more scientists are learning
about our bodies' biologic rhythms. What are biologic rhythms?
In essence, they are the rhythms of life. All forms of life on
earth, including our bodies, respond rhythmically to the regular
cycles of the sun, moon, and seasons.
For example, as night turns into day, vital body
functions, including heart rate and blood pressure, speed up in
anticipation of increased physical activity. These and other
predictable
fluctuations in body function, taking place during specific time
cycles, are our biologic rhythms. They are regulated by "biologic
clock" mechanisms located in the brain.
Although biologic rhythms can be "reprogramrned"
by environmental influences (such as when a person regularly works
the night shift and sleeps during the day), they are genetically
"hard-wired" into our cells, tissues, and organs.
Medical scientists who study the body rhythms
(chronobiologists)
have found that these rhythms can affect the severity of disease
symptoms, diagnostic test results and even the body's response
to drug therapy. (For more information, please read the
Body Rhythms article.)
Among the various biologic rhythm cycles that medical
chronobiologists study, the 24-hour day/night-activity/rest cycle
is considered a key chronobiologic factor in medical diagnosis
and treatment. The circadian rhythm (also referred to as the
"body
clock") is influenced by a specific area of the brain called
the hypothalamus.
Why is the 24-hour body clock so important? Because
so many of our normal body functions follow daily patterns of
speeding up and slowing down, intensifying and diminishing, in
alignment with circadian rhythm. It is now known that the symptoms
of many chronic disorders also depend in part upon the circadian
rhythms, including asthma, allergies, rheumatoid arthritis, blood
pressure elevations (hypertension), and the chest pain of heart
disease (angina).
A study from Standford University's Sleep
Disorders Clinic looked at the National Football League's (NFL's
) Monday Night Football results for possible advantages of West
Coast versus East Coast teams by a circadian rhythm effect.
The fascinating results, which reviewed the past 25 years of Monday
Nite
Football games (which always begin at 9:00 p.m. Eastern Standard
Time),
were published in the journal Sleep (1997;20[5]:362-365). Dr. Roger S.
Smith and colleagues at Stanford found that West Coast teams win
substantially more often and by significantly more points per game
than
East Coast teams.
West Coast teams won 63.5% of games, while East Coast teams won only
36.5%
of games. West Coast teams won by an average of 14.7 points per game,
whereas East Coast teams won by an average of 9.0 points per game.
West
Coast teams won 59.3% of the home games through the years, while
winning
71.0% of Monday Nite Football games. East Coast teams won 56.5% of
their
home games, but only 43.8% of Monday Nite Football home games!
Overall, West Coast team records are 4.4 percentage points better
than East
Coast team records since 1970. However, when West Coast teams play
East
Coast teams for Monday Nite Football, West Coast team records are 27.0
percentage points better than East Coast team records!
Furthermore, West Coast teams performed significantly
better than East Coast even when taking into account the statistical
predicted point spread by Las Vegas odds makers!
These results, the authors feel, are not a result
of jet lag, since this effect should be virtually equal or to
the advantage of an East Coast team traveling westward.
The authors concluded that the power of circadian
rhythms produces an advantage for the West Coast NFL teams during
Monday Nite Football. This advantage they suspect may relate to
the fact that West Coast teams are competing closer to the time
that they typically train each day. This effect not only enhances
home-field advantage for the West Coast teams, but also eliminates
the beneficial effects of home-field advantage for East Coast
teams!
The findings of this study seem to indicate that
athletic performance is enhanced at certain times of day, likely
a result of an effect of the body's circadian rhythm. It also
implies that "it may be more advantageous to perform closer
to one's peak performance time of day rather than try to acclimate
to an opponents time zone."
Last Editorial Review: 8/3/1998