These days, it seems every celebrity has a diet or workout protocol they recommend above all others. As one of the hottest celebrities in Hollywood for years, Jennifer Aniston is no different; recently, she’s been touting the benefits of the so-called 15-15-15 workout plan, or the Jennifer Aniston workout. And trainers say this approach is more than just a gimmick, it’s straightforward and accessible.
The basic idea for this cardiovascular workout plan is to spend 15 minutes cycling on a stationary bike, then 15 minutes on an elliptical machine and finally 15 minutes jogging or running on a treadmill.
Mike Matthews, a certified personal trainer, podcast host and founder of Legion Athletics, a sports supplement company based in Clearwater, Florida, says that 45 minutes of cardio “is a good amount of exercise.” Though he typically recommends a little less — about 30 to 45 minutes of cardio to his clients, as “you can get results with less than that 45 minutes.”
Still, aiming to get 30 to 45 minutes of exercise on five to seven days a week is an admirable goal and “a sweet spot in terms of improving health in various ways,” Matthews says.
Benefits of the 15-15-15 Plan
One key benefit of this type of exercise is improved body composition, or the ratio of muscle to fat. “In 45 minutes of moderately intense exercise, such as biking, elliptical or running on a treadmill, you’re going to burn anywhere from about 500 to 700 calories, depending on how much you weigh and how intensely you’re working out,” Matthews says. Moderate intensity means you can hold a conversation while exercising, but you’d be a little winded.
That calorie burn, if you were to do that seven days per week, could add up to more than 3500 calories. There are 3500 calories in a pound of fat, and while the calculation isn’t exactly one-to-one, “it’s a useful rule of thumb that you have to burn a bit more than 3500 calories to lose a pound of fat,” Matthews says. Therefore, if you’re looking to lose weight, the 15-15-15 plan along with eating healthfully (so as to not take in more calories than you’re burning) can help.
Another upside to the 15-15-15 plan is that it doesn’t have to strictly involve just biking, elliptical and treadmill work. For example, if you don’t have access to a treadmill, you could substitute rowing on a rowing machine. Any cardiovascular modality you enjoy that you can do for 15 minutes at a moderate intensity will suffice.
Ivory Howard, a certified yoga and Pilates instructor based in Washington, D.C., notes that you don’t necessarily have to do all 45 minutes at once, either. “If you don’t have access to all three cardio machines, you could split the workout into a 15-minute elliptical workout and 15-minute bike workout in the morning and a 15-minute run at lunch.” You’ll still be getting 45 minutes of cardio, but it can feel like less of an investment of time.
Any trick that helps you log those minutes can be helpful. The Centers for Disease Control and Prevention recommends that adults get at least 150 minutes of moderate-intensity physical activity (such as biking, using an elliptical or jogging on a treadmill) per week. The CDC also recommends two days of muscle strengthening activity each week.
Generally speaking, getting 30 to 45 minutes of cardio exercise five to seven times per week is best. You can combine the cardio work with strength training days or alternate. The point is to move as frequently as you can.
However, most Americans aren’t getting the prescribed amount of physical activity. “According to the CDC, only 53.3% of adults meet the Physical Activity Guidelines for aerobic physical activity and only 23.2% of adults meet the Physical Activity Guidelines for both aerobic and muscle-strengthening activity,” Howard says.
This has wide-ranging impacts on overall health and wellness. “Many of the leading causes of death and disability in the U.S. are directly linked to a lack of physical activity,” Howard says.
A common refrain as to why so few American adults are getting the exercise they need is a lack of time. This is where the 15-15-15 workout can help. “The 15-15-15 workout can easily be adapted to a person’s needs, lifestyle, and availability, making exercise accessible and encouraging more to workout consistently and avoid many of the leading causes of death and disability in the U.S.,” Howard says.
Who’s It For?
Howard says that the 15-15-15 approach to exercise is “best suited for those who are short on time and/or bore easily of longer cardio workouts.”
By cycling through different exercises, the 15-15-15 plan aims to “keep your workout interesting, and you’re less likely to be bored or injured” by shifting through the various exercises than if you were to, say, just run on a treadmill for 45 minutes straight.
Matthews also notes that shifting from one modality to the next after just 15 minutes keeps things interesting. “Many people would find it boring to just sit on a bike, especially if you’re indoors, for the whole 45 minutes. But by going from one to another, it can make it more interesting.”
Variety is the spice of life, after all. “It also kind of makes it feel like you’re doing three mini workouts,” he says. Anything that helps keep exercise interesting can keep you coming back day after day. “You’re never going to enjoy all your workouts, but we should generally enjoy them and not dread them.”
With exercise, some is always better than none, and Matthews says he sees virtually no downsides to the 15-15-15 plan. “If it appeals to you, I think it’s a great plan.”
Don’t Forget Strength Training
While the 15-15-15 plan offers a manageable way for you to get your cardio in, Howard urges you to remember to incorporate strength training into your overall fitness regimen as well. “I would recommend complementing this workout with strength training. If you have the time, add balance and flexibility to your workout too. You can stretch, strengthen and improve your flexibility in one brief workout session.” Yoga and Pilates, Howard’s main area of specialty, can be especially helpful for building strength and flexibility.
Matthews agrees that strength training should be part of your overall exercise routine. The 15-15-15 plan does offer some strength-building effects — “biking, in particular, can be a good way to improve lower body muscle tone and strength, but it’s not as effective as strength training, such as squatting and doing lunges.”
Getting Started on the 15-15-15 Workout Routine
While Matthews says there are virtually no drawbacks to the 15-15-15 plan, if you’re very new to exercise, it’s best to start out slowly. “If somebody is currently very out of shape and they’re not doing any exercise, jumping right into 15-15-15 is probably going to be too much. This is not where I would start them.”
Instead, he recommends starting with just 15 to 30 minutes per day of walking. “Ideally, go outside and walk for 15 to 30 minutes.” Do that for a couple of weeks until you feel stronger — maybe you’re no longer feeling soreness in the legs or feet and you’re able to walk briskly without getting out of breath. These are signs that your body is adapting to the exercise and you’re ready to move up a level.
That next level might entail walking for 15 minutes followed by 15 minutes of spinning on a bike, followed by another 15 minutes of walking.
You can mix it up to what feels best for you and based on what equipment you have access to, but the main idea should be to ramp up slowly and steadily until you can do the full 45-minute progression.
Matthews also cautions that if you have a lot of weight to lose, it may be better to delay running on the treadmill until you’ve dropped some weight. Running is a high-impact activity that can be hard on the hips, knees, ankles and feet. Carrying excess weight compounds the strain put on the joints. Substituting a lower-impact activity like rowing or swimming can help alleviate some of that strain while still providing an excellent cardiovascular workout that can help you achieve your weight loss goals.
In the end, Howard says, whatever activity or workout plan you enjoy that keeps you moving is probably best. “Our bodies and lives change as we age, and it’s important to find ways to adapt so that we can continue to work out and maintain an active lifestyle.”
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Update 07/07/22: This story was previously published at an earlier date and has been updated with new information.