It’s time for spring cleaning! Get into your closet, dust off your walking shoes, unpack your goggles, and get ready to put a new step into your workout routine. If you’re on the prowl for a fat-burning workout that won’t take too much time out of your day, then read on. It’s time to make your workouts more efficient. If you want to burn a large amount of calories in a short amount of time, take a new look at an old favorite: interval training.

Interval training alternates bursts of high intensity activity with intervals of lower intensity work. Research has found that interval training increases cardiovascular fitness, zaps more calories than a traditional workout, and increases your body’s ability to burn fat. The best part: All of this can be done in a short time—as little as 30 minutes, with all the benefits of a much longer workout. That should pump you up!

During interval training, short bouts of high intensity activity place high energy demands on your body, which burns more calories. So you get the benefit of high intensity training without the ill effects that sometimes go along with it. Interval training also reduces lactic acid buildup in your muscles (which causes the soreness you feel after a hard workout) and potentially prevents overtraining (which may reverse the effects of exercise), according to the Journal of Physiology.


To start, you need to know your rate of perceived exertion (RPE), a scale that measures how hard you’re working based on your ability to breathe during exercise. A good interval workout incorporates training in all three important RPE zones: low, medium, and high (see “Determine Your Rate of Perceived Exertion”). In these tables, we show you how to rev up your walking, swimming and resistance training routines with 30-minute interval workouts.

Interval training isn’t for everyone. As with any new exercise program, consult your healthcare provider before you start. If you’re a beginner, begin slowly. Remember that interval training is harder on your body, so give yourself time to adjust to the demands by slowly progressing to the intermediate and advanced levels.

With interval training, resting is almost as important as the activity; make sure you give your body enough rest between these workouts. Take a 48- to 72-hour break in between sessions to give your body time to recover. Interval training should be done a maximum of two days per week. It should also be done in conjunction with less intensive activities, although on separate days. You’ll need the energy to gear up for the next interval workout!


Whether it’s a brisk walk through the park or a lap around the shopping mall, walking is a fantastic exercise with tremendous benefits. This lower intensity exercise incorporates a large number of muscles and helps burn calories. It also boosts your aerobic capacity. The American Heart Association says that 30 to 60 minutes a day of walking can help prevent obesity, heart disease and diabetes.

To follow our workout, increase your walking speed to reach your medium- and high-level RPE after the warm-up. Perform this workout twice a week with 24 to 48 hours in between workouts. For beginning exercisers, shorten the medium-intensity intervals and lengthen the low-intensity intervals. For advanced exercisers, skip the low-intensity intervals and only perform the medium- and high-intensity intervals.

Swimming is another great calorie-burning exercise, with benefits other exercises can’t offer. Swimming helps mobilize joints and allows you to move with little or no pain. Your body is more buoyant in water, making you roughly 90% lighter in water than on land. If you’re overweight or have joint pain or inflammation, swimming is for you.

For a 150-pound woman, a water workout can burn 500 to 700 calories an hour. If time is a factor, interval training can help you burn a large amount of calories in 30 minutes, alternating high- and low-intensity bouts to rev up that calorie-burning engine. This 30-minute workout is broken into distance intervals. If you’re a beginner, shorten the distance intervals to 50 meters and slow your pace. For advanced swimmers, keep the distance intervals the same, and pick up the pace when swimming the recommended distances.


One great way to get the most out of your program is to combine cardiovascular work with resistance training using a method called peripheral heart action (PHA) training. This method of interval training mimics a regular circuit training method that keeps you moving from one exercise to another, with minimal to no rest in between. However, with PHA training, while you move from one exercise to another you alternate upper- and lower-body exercises.

This increases the intensity of the workout and decreases your time spent training. This method forces blood to circulate quickly through the body, increasing calorie burn and, according to the Archives of Physical Medicine Rehabilitation, decreasing body fat and increasing lean muscle mass. Overall, the same researchers, reporting in the Medical Science of Sports, found that circuit training increased calorie burn compared with similar traditional resistance training, where you may rest for up to 90 seconds in between sets.

To follow this workout, move from exercises 1 to 8 in the order listed, with no rest in between. If you’re a beginner or are new to resistance training, do the same exercises shown but just use less resistance and increase the rest time to 30 seconds between exercises. For advanced exercisers, perform a higher intensity cardio interval like jogging or increase the incline to 5% or higher for the two-minute cardio interval.

Determine Your Rate of Perceived Exertion (RPE)
RPE scale (1-10)	Zone Intensity
RPE scale 1-4: Low	Breathing is easy, you can talk for days.
RPE scale 5-7: Medium	You might be able to hold a decent conversation but not for long.
RPE scale 8-10: High	Hold the phone—you can’t seem to squeak out a hello.

Walking Workout
Time (in minutes)	RPE
5:00 (warm up)	1-4
4:00	5-7
0:30	1-4
4:00	5-7
0:30	1-4
4:00	8-10
0:30	1-4
4:00	5-7
0:30	1-4
4:00	5-7
5:00 (cool down)	1-4

Swimming Workout
Distance	Stroke	Pace	RPE	Rest
100 m	Freestyle	2:00 min	1-4	0
100 m	Kick/swim	1:30 min	5-7	10 sec
100 m	Backstroke	2:00 min	1-4	0
100 m	Butterfly	1:30 min	5-7	10 sec
100 m	Breaststroke	2:00 min	1-4	0
100 m	Kick/swim	1:20 min	5-7	10 sec
100 m	Freestyle	2:00 min	1-4	0
100 m	Kick/swim	1:20 min	5-7	10 sec
100 m	Backstroke	2:00 min	1-4	0
100 m	Breaststroke	1:10 min	8-10	10 sec
100 m	Freestyle	1:30 min	5-7	10 sec
100 m	Breaststroke	2:00 min	1-4	0
100 m	Butterfly	1:10 min	8-10	10 sec
300 m	Freestyle	6:00 min	1-4	0

Resistance Training Workout
Body Part	Exercise	Sets	Repetitions	Intensity	Rest
1 Chest	Seated chest press	3	12	Moderate weight	0
2 Legs	Leg press machine	3	12	Moderate weight	0
3 Back	Lat pulldown	3	12	Moderate weight	0
4 Legs	Step-ups	3	12	Moderate weight	0
5 Shoulders	Seated shoulder press	3	12	Moderate weight	0
6 Legs	Side lunges	3	12	Moderate weight	0
7 Arms	Standing biceps curl	3	12	Moderate weight	0
8 Arms	Triceps kickbacks	3	12	Moderate weight	90 sec
Cardio/Walking for 2 minutes at incline 3% between sets if on treadmill

About the Author: Chere Lucett, NASM-CPT, PES, CES, owns Enigma Fitness and Performance, a company that specializes in fitness and performance training. She lives in Queen Creek, Ariz., and advises women to not be afraid of resistance training. “Women don’t get big and bulky if they are lifting correctly and if their genetics don’t allow it,” she says. “So get out and lift some weights! The benefits far outweigh the possible negatives.”