Letuli does chest presses with suspension bands during
high-intensity interval training at Kri Chay's Urban
HITT FITT gym in Lee's Summit, Mo., on January 20, 2014.
The American College of Sports Medicine named
high-intensity interval training as the top global trend
CITY, Mo. ó Nicole Lindemann, a business owner, wife and
mom, speaks the truth: "Basically, Iím like everyone
else in the world ó weíre not getting any younger or any
better in shape."
resolutionaries, time to bust a move. But how, exactly?
38-year-old Lindemann didnít know that the American College
of Sports Medicine named "high-intensity interval
training" as the top global trend for 2014 when she
signed up for just such an exercise class a few weeks ago.
HIIT, or just say "hit."
term brings anything to mind, itís probably the image of
those cabals of impossibly fit-looking folks sweating it out
on TV commercials. Theyíre hawking such hard-core workouts
as CrossFit and P90X, which are types of high-intensity
the popularity of these well-marketed programs shot HIIT to
the top of the ACSMís trend watch, accompanied with warnings
from fitness experts that extreme regimens can be
injury-inducing and "arenít for everybody."
actually nothing new about intense interval training, which
goes back at least to the 1930s and Fartlek, the famed Swedish
program. And it can be done in a measured way that provides
big exercise benefits without big injury risks, says Kri Chay,
a certified trainer and owner of Urban HIIT FITT in Leeís
latest science backs him up on this. The central idea couldnít
be simpler: Go hard. Then go easier or rest. Repeat.
the notion of alternating relatively intense exercise with
periods of recovery," said Martin Gibala, a kinesiology
professor at McMaster University in Hamilton, Ontario, who has
studied the topic for 10 years. "And it can be properly
scaled for different levels of fitness."
benefits are impressive, Gibala said, and they can be achieved
in about half the time of continuous moderate-intensity
exercise. Thatís a big deal because lack of time continues
to be the No. 1 barrier people cite to getting regular
exercise, he says.
is a newbie in Chayís first-of-the-year, six-week session.
She wasnít interested in becoming an ultra-exerciser. Sheís
busy enough with her 7-year-old daughter and her business,
Kidz First Therapy, which provides occupational therapy for
children with special needs.
does want to be healthier, in better shape and to look better
in her clothes.
start of a recent class, Chay pointed to a dry-erase board
with the sessionís 10 exercises, the set on the left for
newbies and on the right for veterans.
ó 14 women and four men with a range of body shapes ó were
to hit each exercise for 40 seconds, with a 20-second break to
move to the next station.
music blasting, they were to cycle through the 10-exercise
regimen three times. A buzzer marked the end of each 40-second
interval and a bell sounded for the start of the next.
hard, baby," Chay yelled.
were dumbbells, kettlebells, hanging rings and other equipment
at the stations, set up for various types of lifting and
bodyweight, or calisthenic-style, exercises.
circulated, helping with proper form and sometimes offering
modifications of some exercises. A woman with a bad ankle
needed an alternative at one of the stations.
like to incorporate upper and lower body, push and pull,"
Chay said. "They choose their level, and I modify the
program if someone needs it, even on the fly, in the middle of
likes the variety, and she thinks thereís a psychic
advantage to the intervals.
makes me push harder because I know the duration isnít that
long," she said.
that "short-term goal" of the intense interval has
been shown to be a plus for exercisers, not to mention that
the on-off method, even repeated, helps to fight boredom, said
Micah Zuhl, a clinical assistant professor at Central Michigan
Universityís School of Health Sciences.
training is being used in rehabilitation clinics, he said,
even with cardiac patients, which was unheard of just a few
said intervals can be adapted to many types of full-body
workouts, with or without equipment, and is used in swimming,
biking and running, including on cardio machines.
really hot right now is sprint training," he said,
interspersing sprints, rests and jogs of various lengths.
are no set guidelines on interval length, Zuhl said, although
research is showing the best benefits when the high-intensity
portion is set at 30 seconds to two minutes. In studies, the
"go easier" or rest period is often twice as long.
So, for example, 30 seconds of high-intensity effort would be
followed by one minute of recovery.
intense should the high-intensity be?
no free lunch," Gibala said. "If the time-efficiency
aspect is attractive to you, then youíre going to have to go
hard with these intervals."
approach, especially when starting out, he said, is to
"get out of your comfort zone" for the go-hard
interval. If youíre running outdoors, for instance, resolve
to pick up the pace from one streetlight pole to the next,
then back off.
always, talk to your doctor before trying a new exercise
program. A certified personal trainer can help you determine
proper intensity, Gibala said.
targets are a more exact way to determine exertion, but those
also are variable from person to person, he said.
figure the average maximum heart rate for someone your age ó
subtract your age from 220. Then shoot for a heart rate about
85 percent of that number during the high-intense intervals.
40, the average maximum is 180, so the target would be 153
beats per minute.
said many of his studies have used exercise bikes with a
protocol of one minute of intense effort followed by one
minute of recovery, repeated 10 times per session.
Participants performed three of these 20-minute sessions over
shown benefits for people with Type 2 diabetes in just two
weeks," said Gibala, noting that this was a total
commitment of one hour a week. "Their blood-sugar levels
are markedly reduced."
Bracko, an exercise physiologist and ACSM program planner,
said it isnít well-understood why HIIT produces such
time-efficient results. Of course, the exerciser is working
harder during the intense bursts than in any similar periods
of continuous exercise.
physiological benefits might also be a result of both ramping
up and down the intensity, he said, and from the
"after-burn." Itís known that people burn calories
longer after interval training than after continuous or
advocates are so sold on interval training they recommend
jettisoning continuous styles of exercise. But Gibala and
others say thatís unnecessary. They suggest limiting HIIT
sessions to two or three a week, alternating on other days
with continuous or steady-state exercising, including strength
training and cardio.
end of his HIIT class recently, during post-workout
stretching, Chay talked to members not about the workout or
its intensity but about Ö food.
requires class members to record what they eat and drink in
food journals, which he monitors. They must bring their
journals to class, or else.
night somebody forgot their food journal, and we all had to
run outside," Lindemann said.
workouts wonít matter, Chay told participants, if eating and
drinking arenít under control.
canít out-train a bad diet."
high-intensity interval training, the workout possibilities
are nearly endless. Here are three samples of how to
incorporate HIIT into an exercise session. The times and
distances are only suggestions and can be varied for an
individualís conditioning level.
first two are from Kelly Garroutte, an Overland Park personal
trainer with a masterís in exercise physiology. These simple
workouts use full-body exercises ó burpees and mountain
climbers ó that spike the heart rate. Less-intense
exercises, focused on different muscle groups, are used for
the recovery periods. For equipment, the first requires a
cable rowing machine, the second a set of dumbbells. (A quick
online search will explain how to perform burpees, mountain
climbers, dumbbell curls and dumbbell lateral lifts.)
third sample is from Micah Zuhl, a clinical assistant
professor at Central Michigan University. Itís a running
workout with sprints and a jog.
Burpees: 30 seconds
Seated cable rows: 60 seconds Repeat three times.
Dumbbell curl: 30 seconds
Dumbbell lateral lift: 30 seconds
Mountain climbers: 30 seconds Repeat three times.
Sprint: 30 meters (about 100 feet)
One to three minutes
eight to 12 times
jog: Five to 10 kilometers (3.1 to 6.2 miles)