Expert Solutions: Cardio or Strength Training First?

It’s an age-old question, with no right answers. If you have to do both in the same day, does it matter whether you do strength training or cardio first? SparkPeople’s Fitness Experts voice their opinions on this hot topic.

Dean Anderson, Certified Personal Trainer
I think that the ideal would be to do these two forms of exercise on different days (or one in the morning and one in the evening), so that you can devote maximum effort and get the maximum benefit from each. Any time you do one followed by the other, the second one will suffer at least a little (although you may gradually improve your overall endurance this way).

If that’s not possible, then it comes down to a question of priorities and goals–for that day, and overall. If you’re trying to build muscle mass, doing cardio right after strength training is not usually a good idea, because the more depleted your muscle fuel (glycogen) becomes, the more protein you’re body will use as fuel. After an hour of fairly intense exercise, protein may provide up to 10% of the fuel used, compared to the 1-2% it normally provides. That’s the opposite of what you want for muscle building. To increase strength, you want your body to shift into "repair and rebuild" (anabolic) mode as soon as possible after your strength workout, and the best way to make that happen is to eat instead of doing cardio. A light cardio workout before lifting would be better. But don’t try to do a strenuous strength workout after you’ve already tired yourself out with cardio–that’s not safe.

If you’re mainly trying to lose fat and maintain the muscle you’ve got, then doing cardio after strength training can be a good strategy. The percentage of energy contributed by fat goes up considerably after an hour of exercise, and since strength training uses mostly glucose for energy, doing that first will also increase the amount of fat your body uses for the cardio. However, it’s also true that as more fat is being used to fuel the exercise, the less work you’ll be able to put out, and the fewer total calories you’ll burn. Your cardio will probably be less intense and/or shorter than it would otherwise be, and this may cancel out the amount of extra fat actually burned.

Jen Mueller, Certified Personal Trainer
You'll find a lot of different opinions when it comes to this question. I don't know that there is a lot of reliable research to substantiate doing one or the other first, so I think it comes down to individual goals and preference. If your goal is to build muscle mass and strength, you'd probably want to do your weight training first. If your goal is to gain cardiovascular endurance, you'd want to do your cardio workout first. Here's an example. When I train for a marathon, my primary focus is increasing my mileage. Weight training is going to help prevent injury and increase strength, but what matters most is the running and increasing my distance. So in that case, I always do cardio first.

When it comes to weight loss, I recommend doing cardio first. Cardio exercise is going to help you burn the most calories in the shortest period of time. Although weight training is also going to help with weight loss (and should be part of any workout routine), I would make cardio the activity you're going to do while you have the most energy and your muscles are rested. No matter which order you choose, the second activity is going to suffer (to a certain extent) because you've already used up some of your energy. If you can do your cardio and strength training on different days, that would be the ideal situation. But no matter which order you use, you'll want to do a good 5-10 minute warm up before each workout session.

Nicole Nichols, Certified Fitness Instructor
What I always say matters most is that you're actually doing both cardio and strength training—in any order, on any days, at any time—and continuing to push a little harder to become even more fit. While I do agree with the perspective that it’s ideal to do cardio and strength training on separate days for optimal results, most people’s schedules don’t allow that. If you have to do both in one day, your second best option is to do them at different times of day—such as cardio in the morning and strength training in the afternoon or evening. This two-a-day approach gives you time to rest and refuel enough that you’ll have optimal energy once again by the time you get to your second workout.

But exercising twice in one day isn’t feasible for most busy people. If you have to fit in both during one workout, you should focus on whichever exercises will help you reach your main goals, and do those first. Perform cardio first if you want to lose weight, train for an endurance event, or achieve the general health benefits of exercise. Do strength first if you want to build size and power. Be sure to eat something within two hours of starting your workout session and within about one hour of completing it. Keep the length of your combination session reasonable and realistic so that you have enough energy for each part of your workout.

Personally, I do a little bit of everything—cardio first on some days, strength training first on others, cardio and strength on separate days, and even two separate workouts in one day. I like the variety, but also enjoy the mental and physical break that comes when I can focus on just one thing at a time. Changing the timing and order of your exercise program is yet another way to keep your body surprised, stave off boredom, and maximize your results.