By John Porcari, Ph.D., Kirsten Hendrickson, B.S., and Carl Foster, Ph.D., with Mark Anders
Fitness fads come and go, but boot-camp workouts are still among the most popular.
Back in the spring of 1998, the American Council on Exercise first spotted the rapid growth of instructor-led workouts based loosely on the calisthenics used (like push-ups, squat thrusts, punches, kicks, etc.) to whip new recruits into shape in the U.S. Army’s basic-training program. Ten years later, take a look at the class schedules of gyms and fitness centers across the country and you’ll still find boot camp. According to recent stats from the International Health, Racquet & Sportsclub Association, a trade organization for health clubs, 955 of its 3,306 member clubs offer boot camp–style fitness classes. And it’s not just hot in the gyms. A quick scan of the exercise videos offered on Amazon.com yields more than 30 different boot-camp videos.
"There’s a certain element of getting back to the basics and a more functional-training approach," says ACE’s chief science officer Cedric X. Bryant, Ph.D. "People are looking for different experiences. With boot camps, you’re giving them something outside the traditional club environment."
Maybe the boot-camp trend is still going strong because it’s not really trendy at all. The workout is simple and not tied to a single piece of equipment. Or maybe it’s the motivating team-oriented atmosphere that’s created as fellow exercisers ‘survive’ the workouts together.
Whatever the reason, boot camp remains wildly popular, yet surprisingly its efficacy has never been formally studied. "Boot camp is becoming more and more popular in the health club setting so obviously people want to know if they’re really going to get something out of it, and if it’s going to be worth their time," says Kirsten Hendrickson, a graduate student in exercise and sports science at the University of Wisconsin. "So we decided to take a look at it."
To analyze the health and fitness benefits of boot camp–style workouts, a team of exercise scientists from the University of Wisconsin, La Crosse Exercise and Health Program, led by John Porcari, Ph.D., and Hendrickson, recruited six men and six women ages 19 to 29.
All volunteers were given an exercise test on a motorized treadmill to determine each subject’s maximal heart rate(HR max) and maximal oxygen consumption (V• O2 max) to establish a baseline of fitness. Ratings of perceived exertion using the 6–20 Borg Scale, a measure of how hard subjects feel they’re exercising, were also recorded throughout the exercise testing.
Once that baseline was established, the subjects were invited back into the lab to view a 40-minute recorded boot-camp exercise video. Naturally there are many boot camp–style exercise videos on the market, so researchers reviewed a wide range of titles, eventually settling on The Method: Cardio Boot Camp with Tracey Mallett. "We chose that DVD because it has a good blend of aerobic movements and strength moves that you’d picture military guys doing at boot camp," notes Porcari. "Plus we wanted to pick one where people were taxed pretty hard because that’s what you picture when you think of boot camp."
The study volunteers were given a copy of the DVD to take home and practice until they felt familiar enough with the choreography to be able to follow along easily with the workout. At that point, they were asked to return to the lab for testing. Each subject was then outfitted with the Cosmed portable analyzer, a backpack and facemask apparatus that measures oxygen consumption and caloric burn. Heart rate and perceived exertion were also tracked every three minutes throughout the 40-minute workout.
After analyzing the data, researchers found that the average exerciser burns approximately 9.8 calories per minute during a typical boot-camp workout, which equals nearly 400 calories during the entire 40-minute boot-camp video studied (Table 1)
"The biggest benefit is you’re burning an average of 600 calories per hour," says Porcari. "That’s obviously going to help with weight loss, but you’re also getting the muscle-building benefit from pushups, arm curls and squat thrusts that you wouldn’t get just from going out for a fast walk or jog."
According to recommendations set by the American College of Sports Medicine (ACSM), to enhance cardiorespiratory endurance individuals need to exercise at 70 percent to 94 percent of HR max and 50 percent to 85 percent of V• O2 max. Based upon the data collected in this study, subjects were exercising well within those recommended intensity levels. "On average, people were working at 77 percent of heart-rate max, which is considered moderate intensity, but it also gets as high as 91 percent, meaning, all these boot-camp workouts have peaks and valleys," Porcari explains. Figures 1 and 2 offer a visual representation of how heart rate and oxygen consumption varied by the minute as the test subjects followed the video from high-intensity moves like kicking and punching, down to low-intensity moves with the dumbbells, and back up again to high-intensity moves.
"These workouts are designed to be cyclical like that," he explains. "Boot camp is a good form of interval training because you get periods of high intensity interspersed with moves that tend to be lower in aerobic intensity but they serve a whole different purpose—to build muscle strength."
The Bottom Line
Boot camp is an excellent way to enhance aerobic capacity and help control body weight. "I think it’s a great workout with great variety," says Porcari. "It’s a good combination of aerobic exercise and muscle conditioning and it’s much more of a total-body workout than just going out for a run or bicycle ride."
But remember, not all boot-camp workouts are created equal, he warns. Some are heavy on cardio, while others emphasize martial arts–inspired movements or basic strength-training exercises. For best results, our researchers recommend picking a well-balanced program with equal helpings of aerobic movements and calisthenics. However, if you’re looking to improve in a particular area, you might consider looking for a boot-camp class or video that caters to your particular fitness weaknesses. For example, if you’d prefer build more upper-body strength and endurance, consider picking one with more push-ups, squat thrusts and similar moves.
"If people are looking for something that’s fun and variable that will increase their adherence to an exercise program, and, most importantly, burn a lot of calories," says Hendrickson, "boot camp would be a really great option."