A jam-packed weekday schedule makes it difficult to find time for long cardio sessions, but skipping workouts all week can derail your weight-loss effort. The thought of a weekend slog on the treadmill or elliptical trainer trying to make up the difference would hardly fill your heart with joy. With high-intensity interval training, known as HIIT, you can strip fat in minimal time – and keep your fitness plan firmly on track.
With high-intensity interval training, or HIIT, you vary the cardio intensity throughout a training session, instead of plodding along at the same speed. A typical HIIT workout starts with a three- to five-minute warmup before going into the main intervals. Usually your high-intensity bursts last anywhere from 30 seconds to three minutes, though they can be as short as 10 seconds and as long as five minutes. This pushes you into an anaerobic exercise state, which increases fat loss. Break up the bursts with lighter recovery periods of at least the same length as the sprint. For a simple routine, perform HIIT on any cardio machine, interspersing one-minute high-intensity intervals with two-minute rest periods.
Burning more fat in less time might sound like a pipe dream, but it really is a reality. Researchers at the University of Guelph, Ontario, found that in just two weeks of interval training, women increased their capacity to burn fat. Intervals recruit larger muscle fibers and make you work harder, leading to an increased calorie burn. The Idea Health and Fitness Association recommends HIIT for weight loss because the extra demand on your body also means you carry on burning fat after your session ends.
The Centers for Disease Control and Prevention advises a minimum of 75 minutes of vigorous cardio each week for maintaining general health and well-being, though weight loss might require more. If you do it right, HIIT meets the vigorous quota. Aim for three 25-minute sessions, with a day of rest in between, or try five shorter, more intense 15-minute sessions each week. You shouldn't need any other cardio on top of this, though for best results, add two total-body strength-training sessions per week.
Any gym cardio machine works well for high-intensity intervals, though if you fancy a change of scenery go for hill sprints or sprints on a running track, take your bike for a spin or hit the pool for some swimming intervals. You can also combine interval training with a weights workout in a body-weight circuit, explains Jessica Smith of "Shape" magazine. Include exercises such as squats, pushups, lunges, planks and jumps -- work hard for one minute then take it steadier for two. Check with your doctor before starting a workout plan and ask a trainer for help if you need it.
- ACE Fitness: High-Intensity Interval Training
- Oxygen: HIIT: Blast Fat in No Time!
- Idea Health and Fitness Association: HIIT Vs. Continuous Endurance Training: Battle Of The Aerobic Titans
- Centers for Disease Control and Prevention: How Much Physical Activity do Adults Need?
- Shape: Lose Fat Fast: HIIT Bodyweight Workout
Mike Samuels started writing for his own fitness website and local publications in 2008. He graduated from Peter Symonds College in the UK with A Levels in law, business and sports science, and is a fully qualified personal trainer, sports massage therapist and corrective exercise specialist with accreditations from Premier Global International.