Kansas City Royals pitcher Danny Jackson has a pregame ritual that may have helped his team win the World Series. Before every game, he listens to "Eye of the Tiger" from the movie "Rocky." He compares it to self-hypnosis that helps him psyche himself up to play well.

California fitness consultant Jack Riley runs to the theme from "Rocky." "Some rhythms, such as 'Chariots of Fire,' which you would think would be good running songs, are not synchronized," said Riley, who is in the "Guiness Book of World Records" for most triathalons completed in one year -- 52. "Something like Rocky's theme has more of a beat."

With 19 million more stereo headsets sold this year -- many to runners looking for musical accompaniment -- and with the proliferation of aerobic dance classes, music and exercise have become intertwined. What goes in the ears and its effect on the rest of the body has become a new area of fitness fanatacism.

"Music helps make running easier and more enjoyable," said Riley, 53, who prefers "rock music with a synchronized beat," such as the Dubee Brothers or the Beach Boys. Riley uses the tapes for endurance runs of up to 20 miles. With musical accompaniment, he said, "I find that I run harder without knowing it."

Can Duran Duran really help improve your 10-kilometer time? Can aerobics to the tune of Patti LaBelle help you shake your booties more easily than the music of Madonna?

"Absolutely," said Raul Espinosa, a communications aide in the Carter White House and now president of Music in Motion, a service that analyzes top 40 tunes for their effectiveness as accompaniment for aerobic dance. He said that all music is not created equal when it comes to exercise.

"There are many elements in the motivational quotient of a song," said Espinosa. "It's not enough to say, 'Listen to the radio and pick this song and play it in your classes.' And there is much more to the effect music has on the human system than counting beats per minute."

Good exercise music, said Espinosa, depends on what kind of exercise you're doing, at what level and with what purpose. For aerobic dance classes, Espinosa chooses music with 120 to 140 beats per minute for the warm-up and floor work, 140 to 190 for aerobics, 80 to 120 for the cool down, and 60 to 80 for the slow stretch.

The music you use, said Espinosa, should be 10 to 15 beats per minute higher than the "maximum benefit exercise zone" you want to achieve. For example, if you want your heart rate at 160 beats per minute, the music should be at 170 to 185 beats per minute.

Most joggers run at a pace that doesn't fit most popular music, said musician Rick Loewus. On his daily runs through Central Park and on treadmills in health clubs, Loewus sneaked up behind runners and counted the cadence of their run. He found that the average fitness jogger, no matter what age or sex, "seemed to almost always take 168 steps per minute." Since Loewus found that "the runner's pace is a very awkward musical pace," he wrote his own tunes, called "Soul Music," at half that speed -- 84 beats per minute.

But other factors also influence the "motivational quotient" of the music, Espinosa said. How many times you've heard the song before, the breaks in rhythm and the lyrical arrangement can contribute to or detract from the music/exercise effectiveness.

Using Alpha Syntauri and Synclavier composers connected to his Apple commuter, Espinosa gets a printout analyzing each musical piece for 13 different factors, including beats per minute, tonal amplitude, frequent or infrequent changes in rhythm and lyrical arrangement. He then runs the music by a 20-member review board of fitness experts.

Music in Motion rejected "Concealed Weapon" by the J. Geils band, "Turn up the Radio" by Autograph and "Go Insane" by Lindsey Buckingham, all songs in which the rhythm track progressed too fast or changed too frequently to accommodate sets of four to eight exercises. Among the songs they selected for aerobics were "New Attitude" by Patti LaBelle and "Tell Me" by Al Jarreau. While most of the data about exercise/music correlations is very subjective, at least two scientific studies have been done.

Gary Crook, exercise physiologist at Physis, an exercise studio in San Francisco, studied 30 runners who selected their own music -- mostly rock -- running to exhaustion on a treadmill with speed and grade increases every three minutes. Measuring heart rate, blood pressure, respiratory rate and volume and perceived exertions, Crook hoped to find a range of exertion where music would be helpful. He found no signficant difference with or without music.

Last February, Eric Miller, a doctoral candidate in exercise physiology at Ohio State University, studied the effects of using stereo headsets on 10 experienced college-age male runners. On both 30-minute treadmill runs, with and without headsets, Miller tested runners' heart rates, perceived exertion, lactic acid and endorphin levels.

Both beta-endorphin and perceived exertion levels were significantly lower in the music group. "Because they perceived the exercise as less intensive," theorized Miller, "the body thought it needed less pain killer. The physiological stress was the same. But the psychological stress was less."

Miller believes that music tunes out the body's stressful sensory input -- increased heart rate and respiration.

"One thing that was interesting to us was how your perception of stress can influence biochemical levels in the body. If you run with stereo headsets, you can exercise at the same intensity -- but do so with less effort."

If music makes exercise painless, will we see, in future Boston marathons, a field of headset-bedecked runners?


Triple jump master Willie Banks recently threatened to withdraw in Australia when the International Amateur Athletic Federation (IAAF) ruled that he could not use his headset during competition. But after the IAAF was assured that he could not receive coaching signals from the stands, Banks went on to wear the device and listen to "inspiration" music during the competition. He set the World Cup record for the triple jump.

But for amateurs, safety is also a consideration.

"I used to run with music when I lived in a safe area and could run along the C&O canal," said Liz Elliot, director of the American Running and Fitness Association. "Now I live in the country where there are no sidewalks and the average speed is 70 mph. It's just not safe."

In addition, hearing specialists warn that any loud noise, especially when close to the ears, is harmful.

Dr. David Libscomb at the University of Tennessee said stereo headsets can make the wearer "functionally deaf" or cause permanent damage.

Still, used carefully, music may soothe the savage exerciser.

"Everyone says if they have the right music," said researcher Crook, "the time goes faster and it takes less effort."