How Long Do You Really Need to Work Out?

You know it’s important to prioritize fitness, but sometimes life happens and you just can’t allot an hour for exercise. Or maybe you can spare 10 or 15 minutes, but wonder if quick workouts are even worth doing. Can you actually get results from brief bursts of activity? How long should you work out each day and week if you want to lose weight and/or build muscle? Here’s all you need to know to determine your “optimal dose” of exercise.


How Much Exercise Do You Really Need?

When it comes to how long and frequently you need to work out, more isn’t necessarily better.

“You don’t need to spend hours a day exhausting yourself in pursuit of a leaner, fitter, more defined body,” says Trevor Thieme, C.S.C.S., Openfit’s fitness and nutrition content manager. “In fact, exercising too hard or too often (or both) can actually be counterproductive, sabotaging instead of maximizing your results by overwhelming your body.”

To keep your heart and body healthy, the American Heart Association recommends 150 minutes per week of moderate activity, or 75 minutes per week of vigorous activity. We’ll save you the math: that’s about 30 to 50 minutes of moderate, steady-state exercise three to five days a week, or about 25 minutes of high-intensity work three days a week.

Is it bad to work out every day?

While it’s not bad to work out every day if you have the time and energy, don’t feel like you need to go full throttle seven days a week. Recovery days are important for helping your body repair and strengthen itself, so take them when you need them.

“Adaptations like muscle growth, strength gains, and fat loss happen between workouts, not during them,” says Thieme. “So prioritize your recovery as much as you do working out.”


Workout Length = Fitness Level + Exercise Intensity

So how then can you determine the optimal dose of exercise for you? “There’s a direct correlation between workout intensity and duration. As workout intensity increases, workout duration decreases,” says Thieme, explaining that the greater your effort is, the faster you’ll tucker out, and the shorter the workout will have to be. “But keep in mind that your fitness level is also a key factor in determining how hard and how long you can go.”

If you’re a hundred pounds overweight, an hour-long, even paced walk might be as intense a workout as your body can handle. But if you’re an elite athlete, you might be able to crush 30 minutes of all-out, high intensity interval training (HIIT) with energy to spare. That’s why there’s no “perfect” workout length — every body is different.

There are external factors to consider, like workout type. “Think of a HIIT workout versus a typical weightlifting workout,” Thieme says. “You’re going to do much more work in much less time with HIIT, making that a more intense (and thus shorter) training session.”

And when you’re getting started, everything can feel pretty intense, so it’s OK if you can’t power through a high-intensity workout for very long.

Here’s how to gauge whether you worked out hard and long enough: “If you feel like you were challenged, but also feel energized, you nailed it,” says Thieme. “If a workout leaves you completely spent and exhausted, however, you likely exercised to excess.”


What If I Don’t Even Have 30 Minutes to Work Out?

“There’s a threshold below which you won’t see results,” says Thieme. “No one can work out for a few minutes a day and expect to lose significant amounts of weight, pack on significant amounts of muscle, or build significant amounts of endurance.”

But if you can’t dedicate 25 to 30 uninterrupted minutes to a single workout, there’s good news: Research suggests you can break those longer sessions into quick workouts and still get similar cardiovascular and health benefits. Indeed, one study found that consistently accumulating physical activity over the course of a day in 10 minute blocks or less can help lower triglycerides, waist circumference, and BMI, and increase HDL (good) cholesterol to an extent similar to that achievable through longer, complete workouts. And if your goal is weight loss, those smaller exercise blocks might actually be preferable.

“You’ll spike your metabolism three times instead of once,” Thieme says, explaining that your metabolism remains elevated after exercise as your body recovers. “So while you’ll burn fewer calories in each individual session, you’ll burn more calories overall.”

That said, it can be tough to get motivated three times a day. You’ll need to get dressed, show up, do the workout, and get back to whatever you were doing before — every single time. So it’s not the most efficient way to work out.

“All of that takes time, and it adds up,” Thieme says. “Doing multiple quick workouts is going to suck up a lot more of your day than simply doing one longer one.” If you struggle with willpower, the one-and-done approach may work better for you.


Are Quick Workouts Effective for Building Muscle?

Breaking up your routine into quick workouts throughout a day can work well for cardiovascular and weight loss goals, but you’ll need to commit to a longer workout if you want to get swole.

“You’re just not going to get much out of doing mini strength workouts, because that will give your muscles too much rest,” Thieme says. “In order to build muscle, you must first break it down a bit, and you simply won’t do that sufficiently if you try to split up a longer strength training session into multiple shorter ones.”

That said, neither do you need to waste hours pumping iron to see results. “Studies show that you start to see diminishing returns after about 18 to 24 total sets,” says Thieme. “That traditionally breaks down into about three to four sets of six to eight different exercises, and it really shouldn’t take you any longer than about 60 minutes max.”

If you spend more than an hour strength training, you’re either resting too long between sets or exercises, or you’re trying to cram too many exercises into your workout.


So How Long Should You Work Out?

Regardless of whether your goal is greater strength, longer endurance, or a smaller waist, the bottom line is that you really shouldn’t stress about how long your workout should be.

“The key is to find the right balance for your body, fitness level, and goals,” Thieme says. “You need to challenge your muscles, heart, lungs, and circulatory system — and to challenge them just enough each workout to trigger adaptation. That’s going to change as you become fitter, so just listen to your body, and exercise accordingly.”