For many people, working out is a non-negotiable part of the day. Whether it’s early in the morning, before lunch, or late into the evening, most of us schedule devoted time in our day to strengthen our hearts, lungs, and muscles.

This got us wondering: what is the ideal workout duration? We took this question to Twitter, and 30-60 minutes seemed to be the sweet spot for most of our audience. There’s also a bit of uncertainty around this topic, which is fair, given the amount of information — both good and bad — on how long you should exercise.

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Some people may be unsure about what the ideal workout length is if they want to improve their health and fitness. Of course, what is ideal for one person might not be ideal for the next. In reality, the ideal workout duration should be whatever the science has shown to be best for improving health outcomes. It should also be a workout length that you enjoy, are capable of performing, and which can fit into your day. Unfortunately, that can get a bit tricky, but we’re here to help!

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Defining “optimal”

It’s difficult to define what “optimal” means for everyone. The optimal workout duration is going to depend on a lot of factors including your current fitness and training status, your willingness to devote time to exercise, life obligations, and your day-to-day schedule.

Your goals also matter. Are you looking to maintain your current fitness and body composition, or are you looking to make improvements in endurance, strength, and muscle mass?

There’s a big difference between the optimal workout duration needed to maintain fitness and the duration needed to improve it. In this article, we will provide evidence-based recommendations for both. It’s important to note that there will be points in every training program when we should strive to improve fitness, and times when we will need to coast along and maintain fitness. We can’t always be on the upward curve of our fitness journey.

After diving into the science of training, we’ve developed a comprehensive list of the optimal workout duration for all types of fitness goals, which you can use to fine-tune your weekly workout schedule.

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The optimal workout length for maintaining and building endurance

If cardio is your game, then it’s likely that you’re used to putting in lots of hours of running or cycling. Endurance sports require a lot of volume in order to succeed, but that doesn’t mean you need to be logging Ironman-like mileage to reach a high level of fitness. Unless you are training for an ultra-endurance race, an insane amount of weekly volume might not be any better for improving your fitness than a more conservative amount — the cost-to-benefit ratio might start to increase.

Let’s start with the minimums. What is the optimal workout duration if you’re someone who just wants to maintain their level of fitness over time? It’s probably less than you might think.

Studies have found that your short-term endurance for exercise 5-8 minutes in length and your maximal aerobic capacity (VO₂ max) can be maintained for up to 15 weeks with a workout duration lasting 30-40 minutes performed just 2 days per week. One caveat — you have to keep the intensity level up around 80-100% of your maximal heart rate!

Some evidence suggests that as little as 13-26 minutes per workout session can maintain aerobic capacity, but you might have to work out 5-6 times per week and keep the intensity high.

Keeping up your longer-term endurance capacity or performance during exercise lasting 1-3 hours might require at least 26-30 minutes per workout on 2-3 days per week, just for maintenance.

In short: for maintaining aerobic fitness, the volume needed per workout might be fairly low — with the optimal workout duration is somewhere between 13 minutes on the low end and 40 minutes on the high end. Do at least 3 moderate- to high-intensity sessions per week, and you can maintain your endurance for around 3-4 months or more.

The optimal workout duration changes a bit when we talk about what it takes to improve aerobic fitness or endurance. Before we go into workout duration, let’s discuss the weekly volume that seems to be optimal for fitness gains.

Most research has concluded that an energy expenditure of ~1,000 calories per week — equivalent to 150 minutes of moderate-intensity or 75 minutes of high-intensity activity — is best for improving fitness and other markers of cardiometabolic health. However, it’s important to note that some epidemiological studies show that people who exercise well above this amount may experience even greater benefits for healthspan and mortality risk.

Achieving this weekly volume is critical if you want to improve your aerobic fitness, but how you achieve that volume will determine what your optimal workout duration is.

The two most popular ways to reach your weekly total are to exercise 3 or 5 days per week. This means that if your schedule and time allow for 3 days per week of cardio, your optimal exercise duration is somewhere between 50 and 60 minutes. If you’ve got more days to train, split your cardio sessions into 5 workouts per week and aim to get in 30 minutes per workout. Both workout lengths seem to be equally effective when the exercise volume is matched during the week.

Here’s a nice conclusion from a meta-analysis on exercise training that seems to sum up what we know about the optimal exercise duration: “Aerobic training at an intensity of 66-73% of heart rate reserve (maximum heart rate minus resting heart rate) performed for 30-40 minutes per session at least 3 days per week is optimal for maximum cardiorespiratory fitness benefits.”

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The optimal workout length to maintain and build strength and muscle mass

When we talk about duration or length in relation to resistance exercise, things can get a bit more complicated because, unlike aerobic exercise, a strength training session involves a combination of sets, reps, and recovery periods — making a single time prescription difficult.

However, as we’ll see below, most of us can obtain the necessary training stimulus in around 30-60 minutes per workout, but this will depend on whether your goals are to maintain or your strength and muscle size or improve these outcomes.

Let’s talk minimum effective dose. Training studies have shown that as little as 1 workout per week can maintain muscle strength and sprint speed. The same goes for muscle size — younger adults can maintain muscle size from once-per-week training. For older adults, 2 sessions per week seems to be the bare minimum.

What’s the optimal duration for a strength training workout? It’s hard to give a definitive answer here, but performing a minimum of 1-3 sets per exercise for 5-6 different exercises will put you somewhere around a workout length of 30 minutes. Keep in mind that to maintain strength and size with the minimum volume of exercise, you need to keep your intensity high enough and lift at a greater percentage of your maximum ability for each particular exercise or muscle group.

For those looking to build strength or muscle mass, the optimal workout duration is probably somewhere between 45-60 minutes. This is because rather than 1 set per exercise, 2-4 sets is optimal to achieve strength and size improvements. While some research shows that a single set can effectively increase muscle size and strength, this is likely only applicable to individuals who are newer to training with a lot of room for improvement (so called “newbie gains”).

What about the length of rest intervals? 2-3 minutes between sets is the most effective duration if your goal is improving size or strength. This allows enough time to replenish energy stores between sets of exercise and recover a muscle’s force-generating capacity before working it again.

The optimal workout duration will be determined by how many sets you perform and how many exercises you do. It’s recommended that untrained and recreationally-trained people perform 4 sets per exercise and about 5-6 different exercises per workout. This equates to around 45-60 minutes for the optimal workout duration (not accounting for the time it takes you to drive to and from the gym, of course).

Those with more experience may need a bit more volume — up to 8 sets per exercise — to see further improvements. However, increasing intensity can also be one way to gain strength and size. That being said, experienced lifters can see significant improvements in fitness with a workout of 45-60 minutes done 2-3 times per week.

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The optimal workout length to boost cognitive performance

Sometimes we choose to exercise for more than fitness or the calorie burn. Exercise — particularly aerobic exercise — can be a potent brain- and mood-boosting tool to use before a big meeting, presentation, or long writing session. There’s a good deal of evidence to support the cognitive health benefits of exercise, but if you’re looking for a quick hit for cognitive performance — the exercise version of an espresso shot — what’s the optimal workout duration?

One study comparing the effects of a 10-minute, 20-minute, and 45-minute moderate-intensity aerobic exercise workout found that 20 minutes provided the biggest improvement in cognitive performance.

The bare minimum workout length to increase brainpower seems to be 10 minutes, and many of us have probably noticed a significant mood improvement from even a 10-minute walk. However, the optimal length for cognitive performance appears to be 20-30 minutes, and to some extent, higher-intensity exercise is better for this outcome. When exercise goes on for too long, we might actually see a significant decline in cognitive performance due to fatigue and a reduction in energy stores.

This is good news if you’ve only got time for a quick workout during a lunch break or in between meetings. While 20 minutes might not be enough for the significant fitness improvements discussed above, it’s enough to benefit your brain.

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“Optimal” is whatever is optimal for you

We’ve talked about the optimal workout length for achieving a variety of goals related to endurance and strength performance, but there are two more variables to consider when talking about optimizing any exercise routine. Those variables are your weekly/daily schedule and your enjoyment level — both of which determine your ability to reach your goals and sustain a regular habit of exercise.

Some of us have more available days in the week to devote to training, and some of us less. By figuring out how many days per week you can set aside for a combined cardio and strength program, you can develop a bulletproof workout routine. All of the evidence suggests that you should perform cardio 2-3 days per week, with another 2 days being devoted to strength or resistance training. It’s also possible to do both on the same day, without the fear of compromising your gains in cardio or strength.

The volume of exercise needed to improve fitness may be well known, but how you distribute that volume will determine your optimal workout length. Exercising fewer days per week means you’ll need to put a little bit more time in per session. More frequent workouts allow you to spend less time per session, which may be ideal for some people.

Finally, we should talk about preference. Some people love going out for a 1-2 hour run or bike ride a few times per week. Others dread the idea of exercising for any longer than 30 minutes. The optimal workout length is also the length for which you can stay motivated, focused, and maintain a reasonable sense of enjoyment. You don’t need to exercise for an hour at a time if you hate doing it. Maybe it’s something to build up to.

We can talk all day about the optimal workout duration, but in the end, finding what’s optimal for you is a process of self-experimentation and will depend on what state of life or training you’re in.

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Your optimal weekly exercise Rx

Here’s a summary of the science on optimal workout duration.

• To maintain short-term endurance and maximal aerobic capacity, a once-weekly workout of 13-26 minutes can be effective, as long as the workout is of a high enough intensity.
• For long-duration endurance, a workout duration of 26-30 minutes done 5-6 times per week is enough to maintain fitness.
• To maintain muscle strength and size, a workout consisting of 1 set per exercise each week seems to be enough, though 2-3 sets per exercise may be more effective. This could be achieved in a workout of around 30 minutes.
• For a cognitive boost, a 20-30-minute moderate- to high-intensity workout is more effective than shorter- or longer-duration workouts.
• Building aerobic endurance and improving cardiorespiratory fitness requires a workout duration of 30 minutes (done around 5 times per week) or 50 minutes (done around 3 times per week).
• Higher intensity workouts can also improve fitness with a workout duration of 20-30 minutes done 2-3 times per week.
• For building strength and muscle mass, a workout of 45-60 minutes seems to be optimal and is plenty of time to complete 2-3 sets of 5-6 exercises.
• Your optimal workout duration is easy to calculate. Just take the optimal training volumes per week and split them across 3, 4, or 5 exercise sessions.

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