By Dorene Internicola
NEW YORK (Reuters) - For people who are too bored or busy to spend an hour on a treadmill an exercise regime that was developed for athletes but is being taught in gyms may help to build fitness in less time.
The Tabata Protocol is a four-minute regime that measures fitness in seconds - 20 seconds of full-out work followed by 10 seconds of rest, repeated eight times.
Although it can boost fitness levels of the healthy and time-pressed, experts say it is not for everybody and should not be done every day.
"Tabata is about all-out maximum effort," said Jessica Smith, a Miami-based fitness expert and Tabata coach, adding it is a good workout in a shorter amount of time, especially for people who don't have hours to spend at the gym.
"The intensity has to be high to get the benefits, but you don't want to do it too often."
The Tabata Protocol was developed by Dr. Izumi Tabata after the Japanese scientist conducted tests on two groups of athletes, comparing moderate intensity training with high intensity interval training (HIIT).
He found that short bursts of highly intense exercise were at least as effective as hours of steady moderate training.
While Tabata falls under HIIT, its preset work-to-rest ratio is more specific, and usually more demanding, than other interval workouts, which can encompass anything from boot camps to circuits.
"HIIT has more leeway," said Smith. "The intervals can be longer."
The Tabata Protocol can be followed with kettlebells or on treadmills.
Rachel Buschert, who leads a Tabata group fitness class at an Equinox gym in New York, follows the protocol as closely as she can in a group fitness setting.
"The idea is to tax your body in 20 seconds," she explained.
The high intensity work, which often consists of push-ups, squat thrusts and jumps, fills about 20 minutes of the 45-minute class. The rest is recovery, warm up and cool down.
For general fitness, a Tabata class twice a week is recommended, but should not be done on consecutive days. Buschert recommends people who try Tabata start from a base of aerobic fitness.
"If you can't do one push-up, how can you do 20?" she said. "This is for that person who wants to up the ante."
Mark P. Kelly, an exercise physiologist with the American Council on Exercise, said HIIT has been proven effective in improving athletic performance and enhancing weight loss.
"During high-intensity intervals the heart rate goes really high and remains high even during the rest periods," he said. "Various hormones kick in that build muscles and burn fat."
HIIT also pushes the anaerobic threshold, the level of exercise intensity at which lactic acid builds up in the body faster than it can be cleared away, to enable the exerciser to perform at even higher intensity.
Kelly said the Tabata Protocol, while effective, is definitely not for the beginner, but for the experienced and even advanced exerciser. Dizziness and shortness of breath are two quick indicators that people overdoing it.
Kelly advocates a well-rounded program, especially for the non-athlete.
"Harder or more is only better up to a point," he explained. "Do other things. Maintain flexibility, maintain good joint mobility. Do resistance to strengthen muscles. Do longer aerobics. Build your aerobic base first."
(Editing by Patricia Reaney and Nick Zieminski)