It’s a question currently being asked by personal trainers, gym instructors, and gym goers alike: Which is better — a longer, consistent workout like walking, running, or biking for 30–60 minutes, or a shorter routine involving intense bursts of cardio exercise like jumping jacks interspersed with moderate activity or rest?
More and more the answer is HIIT, or High-Intensity Interval Training, which alternates low-to-moderate intensity intervals with high-intensity intervals. HIIT is often incorporated into group exercise classes or as part of CrossFit or Tabata circuit training workouts. It’s based on a 1996 study by professor Izumi Tabata from Japan’s Ritsumeikan University, initially involving Olympic speed skaters using 20 seconds of ultra-intense exercise followed by 10 seconds of rest, repeated continuously for four minutes.
In a recent study by Queens University in Canada, high-intensity, circuit-style training helped improve both cardio-respiratory fitness and strength, even with workouts totaling less than 30 minutes a week. Other studies have shown that just four minutes of interval training can boost fitness levels as much as 30 minutes of running on a treadmill. While a long run will help you burn more calories than a HIIT workout, an interval program will improve your overall fitness. So for those who use lack of time as a reason not to exercise, a HIIT program can offer a whole body workout in half the time of an hour-long fitness class or long run.
HIIT classes have invaded gyms across the country and the Bay Area, including the San Francisco JCC and Presidio YMCA. According to Laura Greenfield, fitness and community wellness manager at the SFJCC, HIIT is considered to be much more effective than normal cardio because it increases both aerobic and anaerobic endurance while burning more fat. “It’s easy to incorporate HIIT into your workout routine,” Greenfield says. “At the gym, if you’re on the treadmill, jog or walk at your normal pace for four minutes, then sprint for one minute, then return to jogging for the duration of your workout. Once that becomes comfortable, increase the sprint portion by another minute or two. The goal is to increase endurance.”
Greenfield adds that even if you don’t have a gym membership you can still add high-intensity training to your workout. “High knees, fast feet, jump squats; those will get the job done. Just focus on increasing your intensity and your heart rate for a few minutes during your workout. Aim for 8-to-10 cycles of low-to-high intensity during your exercise session.”
Our days are packed with work, family, and everything else life throws at us. It’s nice to know we can get a solid workout in a reasonably short time. Check out the high-intensity interval workouts offered at most gyms in the city. Or create your own!
photos: courtesy JCCSF
