Want to Work Out Twice a Day to Boost Weight Loss? Here's How to Do It Safely

Once reserved for serious athletes, two-a-day workouts, or working out twice in one day, has hit the mainstream. Doubling down on your workouts can give you a nice push toward your weight-loss goals, but there are some drawbacks if you're not performing those two-a-days correctly.

So, is working out twice a day right for you? Here's the rundown on this type of workout, some tips on how to do it safely and effectively, as well as a sample week to help kickstart this new routine.

If you're exercising more, you're going to be burning extra calories. Of course, you'll only get this benefit when you increase your total exercise time, not when you're just dividing the amount of time you usually work out in half.

‌How to Make It Work‌

If you normally work out for 30 minutes five days a week, try splitting your workouts into one 20-minute workout and one 25-minute workout. That's an extra 15 minutes of calorie-burning activity each day and an extra 75 minutes each week.

When deciding how much activity to do for both workouts, keep in mind the recommendations from the U.S. Department of Health & Human Services. The organization suggests that adults get at least 150 minutes of exercise each week, which can be increased to 300 minutes per week for even greater results.

When you exercise, you increase the number of calories you burn per hour, even in the hours after your workout. This is often referred to as exercise afterburn, or excess post-exercise oxygen consumption (EPOC), according to the American Council on Exercise (ACE). An EPOC is the amount of oxygen required to restore your body to its normal resting state.

For example, when you exercise, your heart rate increases, your oxygen needs increase and your temperature changes. It takes energy for your body to return balance after exercise, and with energy use comes more calories burned. Energy is also required to heal muscle damage, build muscle fibers and build bone mineral density, all of which can continue after exercise, per the ACE.

As balance is restored, you return to your basal metabolic rate, or the rate of calorie burning needed for just basic functions, such as breathing. When you split your exercise routine in two, you get the benefit of two exercise afterburn time periods instead of one.

‌How to Make It Work‌

And the best thing about EPOCs? It's about intensity, not duration. When exercising at higher intensities, energy is needed immediately and then exhausted in a shorter amount of time. So you're burning calories while working your butt off, then burning calories to recover and restore the energy you used up. If you do a 25-minute strength training routine in the morning and then a 20-minute HIIT workout later on, you'll be a calorie-burning machine while saving a lot of time.

Any type of workout takes time from your day, and if you're already struggling to fit in one, two can feel beyond overwhelming. But it's possible that exercising twice a day could actually be ‌more‌ convenient for your schedule.

‌How to Make It Work‌

If it's difficult to fit in a 30-minute workout, you may settle for one 20-minute session if that's all you can spare at once. If you have 20 minutes free in the morning ‌and‌ another 20 minutes free at night, however, you'll increase your exercise along with your calories burned, which can help boost your weight loss.

In order for any workout plan — especially two-a-days — to be done effectively and safely, you need to balance your physical activity with recovery time, according to a March 2015 article in ‌ACSM's Health & Fitness Journal‌. Too much overload and inadequate rest can result in both physiological and psychological symptoms that hinder performance and may cause you to stop your workout routine.

Recovery and rest, especially between your more intense workouts, are important. This is the time when muscle tissue repairs and muscle growth occur — usually 24 to 72 hours depending on the intensity and duration of the session.

You also shouldn't feel totally wiped out following a tougher workout — you should feel like you could push a little further. And of course, proper nutrition and hydration are critical in order to refuel (but more on that in a bit).

‌How to Prevent Burnout‌

"You don't want to do two high-intensity weight-training sessions in one day," says Derek Morris, ISSA-certified personal trainer and certified nutritionist. "This would be way too much stress on your central nervous system and burn you out fast. A more sensible approach would be to do a weight or resistance training session in the morning and then cardio at night. Keep both the morning and night training sessions to an hour or less."

The more you work out, the more at risk you are for injury. And that's why mixing up your workouts, resting your tired muscles and knowing proper form and technique are so important, according to the U.S. National Library of Medicine.

‌How to Prevent Injury‌

Repetitive movements — working the same muscle over and over — is something you definitely want to avoid while strength training.

"For instance, if you were doing the exact same bicep curls every time you train them, you could potentially develop tendinitis," says Morris. "It's best to rotate some of the accessory exercises to get a more well-rounded stimulus of the muscle groups."

Proper technique is also very important, according to Harvard Health Publishing. Learning the right form of any exercise or how to properly work a machine will help safeguard that body. Remember to warm up, gradually ease into a new workout and always listen to your body. Asking a trainer for help is always a great idea, too!

When you change up your workout routine, it's important to develop a fueling plan that matches its intensity. Morris explains that weight-loss efforts could actually be thwarted if the body is thrown into too deep of a calorie deficit, with not enough rest and nutrition to support bodily function.

"The body wants to hang on to fat cells in a severe calorie deficit," he says. "Fat is needed more than muscle in a situation of starvation, which is essentially what people are doing when they burn way over what they should compared to what they are eating."

For example, Morris adds, if you're only eating 1,000 calories a day but burning 2,000, your body will have no choice but to break down muscle tissue in an effort to free up calories for daily energy use. "Careful planning must be made to ensure efforts result in fat loss and not muscle wasting," he says.

‌How to Get the Right Nutrition‌

It's critical to be mindful of what you're putting into your body. If most of your food is coming out of a package with an ingredient list a mile long, try eating more whole foods instead, like fruits, vegetables, whole grains, lean meats and healthy fats like olive oil, nuts and seeds, per Harvard Health Publishing.

Consider adopting a Mediterranean diet, which is based in these foods and has proven benefits for weight loss, according to the University of Pennsylvania Medicine.

Ready to start with two-a-days? It's probably best to plan out your week before jumping in headfirst. A little planning will help you get the most out of your workouts, with proper rest and injury prevention. Below, Morris shares a safe and effective sample week of two-a-day workouts.

You don't have to make two-a-days the standard for every workout day. Do what you can and what's best for your schedule. If you can only squeeze in one workout on a certain day, you're still ahead of the game.