FITNESS magazines and Web sites love to ask readers about their
favorite workout music while presenting their playlists or suggestions
from celebrities. Self.com features the " '80s cardio playlist," which
includes the short-shorts video classic "Wake Me Up Before You Go-Go"
by Wham! On Fitnessmagazine.com, the singer Rihanna reveals her
favorite workout songs - immodestly recommending four of her own for
"when you have to pick up the pace on the treadmill."

The playlist fixation has a scientific basis: Studies have shown that
listening to music during exercise can improve results, both in terms
of being a motivator (people exercise longer and more vigorously to
music) and as a distraction from negatives like fatigue. But are
certain songs more effective than others?

Generally speaking there is a science to choosing an effective
exercise soundtrack, said Dr. Costas Karageorghis, an associate
professor of sport psychology at Brunel University in England, who has
studied the effects of music on physical performance for 20
years. Dr. Karageorghis created the Brunel Music Rating Inventory, a
questionnaire that is used to rate the motivational qualities of music
in the context of sport and exercise. For nearly a decade, he has been
administering the questionnaire to panels representing different
demographics, who listen to 90 seconds of a song and rate its
motivational qualities for various physical activities.

One of the most important elements, Dr. Karageorghis found, is a
song's tempo, which should be between 120 and 140 beats-per-minute, or
B.P.M.  That pace coincides with the range of most commercial dance
music, and many rock songs are near that range, which leads people to
develop "an aesthetic appreciation for that tempo," he said. It also
roughly corresponds to the average person's heart rate during a
routine workout - say, 20 minutes on an elliptical trainer by a person
who is more casual exerciser than fitness warrior.

Dr. Karageorghis said "Push It" by Salt-N-Pepa and "Drop It Like It's
Hot" by Snoop Dogg are around that range, as is the dance remix of
"Umbrella" by Rihanna (so maybe the pop star was onto something). For
a high-intensity workout like a hard run, he suggested Glenn Frey's
"The Heat Is On."

Music preferences are as idiosyncratic as workout routines, of course.
Allison Goldberg, a 39-year-old life coach and amateur runner who
lives in Texas and who is training for the Houston Marathon on Sunday,
has been running to the Green Day CD "American Idiot" because, she
said, "There's no way you can run slow to Green Day." (Though she may
not be listening on race day; a rule bars runners from using portable
music players and headphones.) Haile Gebrselassie, the Olympian from
Ethiopia who has won the gold medal at 10,000 meters, often requested
that the techno song "Scatman," which has a B.P.M. of around 135, be
played over the sound system during his races.

Ms. Goldberg also includes on her playlist "Don't Phunk With My Heart"
by the Black Eyed Peas (130 B.P.M.), "Mr. Brightside" by the Killers
(150 B.P.M.), and "Dancing Queen" by Abba. The musical style that
seems to most reliably contain a high B.P.M. is dance music, said
Richard Petty, the founder of Power Music, a company that has produced
workout compilations for instructors and fitness enthusiasts for two
decades. "A rock song doesn't have that same consistency," said
Mr. Petty, a former D.J. who takes a metronomic approach to making
exercise music: He chooses a hit song with a catchy melody - say,
"Gold Digger" by Kanye West - and produces a remix whose B.P.M. count
is tailored to experience level and type of workout.

For a stroll walker going at a pace of around 3 miles an hour, a
remixed track has a count of 115 to 118 B.P.M.; for a power walker
going 4.5 m.p.h., the count is 137 to 139 B.P.M., while the B.P.M. for
a runner elevates to 147 to 160.