Despite headlines promising “exercise in a pill,” we’re not there yet.
If you want all the benefits of physical activity — general health, immunity, longevity, fitness, and more — you’ve still got to put some time in. And it’s worth it! But how much time?
Today we’re sharing the science of how much time you really need to spend working out, depending on your goals.
Before we dive into the specifics, let’s lay the groundwork for workout durations.
Three Golden Rules of Fitness
Rule 1: quality of movement is always more important than quantity
Even a single repetition executed with impeccable form is better than a sloppy, high-rep set. An intelligent workout is one that doesn’t injure you.
The same is true of aerobic activities. Performing cardio at the correct intensity and duration for your goals is better than endless “junk miles.”
Rule 2: some movement is always better than none
Whatever your goal, there is a minimum effective dose, and it’s often much less than you think. Even if you have limited time or energy (which happens to all of us), just a few minutes of activity can have huge benefits compared to doing nothing.
Rule 3: fitness and health are both lifelong pursuits
While it helps to have a short-term goal (running a 5K, getting stronger, burning off some unwanted fat), it’s far more important to keep coming back.
The best way to stay engaged with exercise is to choose activities that are fun, motivating, and make you feel good. Don’t let trends or other people influence you on this. As long as you’re showing up for some kind of exercise, you’re absolutely on the right track.
How Long Should You Work Out for General Health?
Physicians recommend 150 minutes per week of moderate-to-vigorous physical activity. The guideline is based on evidence showing that this amount of activity reduces the risk of dying of any cause by about 26%.¹
The good news is that virtually any activity that elevates your heart rate helps you stay healthy, and you don’t need to go overboard on intensity.
Examples of moderate-intensity activities:²
- Brisk walking
- Riding a bike with light effort
- Playing tennis doubles
Examples of vigorous-intensity activities:²
- Riding a bike fast
- Playing soccer
Recent evidence also suggests that you don’t have to do exercise in extended “bouts” — in other words, your activity can be sporadic and you can still get the same health benefits.³
The study of nearly 5,000 adults aged 40 and up found that including sporadic activity throughout the day along with extended exercise sessions when possible gave equally good results and also allowed the participants to get more total activity per day.³
The people who got about an hour of total activity per day were approximately 50%-70% less likely to die than people who were sedentary, while adults obtaining about 95-100 minutes per day of total activity were around 80% less likely to die of all causes.³
An hour or more of activity may sound like a lot, but with this approach, you get to count vigorous walking that isn’t part of a scheduled exercise session. You can also split up your daily activity any way you’d like.
If you’d prefer not to total up the amount of time you spend being active each day, you can also use a pedometer (step counter) to track how much you walk.
In a Lancet study review of over 47,000 adults, researchers found that increasing step counts reduced the risk of death by up to 53%:⁴
- In people under 60 with 8,000-10,000 steps per day
- And among adults aged 60 or older with 6,000-8,000 steps per day
And if you’re really limited in time, you can still get significant health benefits with about 5,000-6,000 total steps per day at a brisk pace.⁴
How Long Should You Work Out for Weight Loss?
Similar to working out for general health, moderate daily activity also works for weight loss. To lose weight or shed unwanted fat, your workouts matter, but not as much as your diet.
One pound of body fat contains approximately 3,500-4,000 calories (kcal). To lose a significant amount of weight, you’ve got to do several things:⁵
- Create a calorie deficit (burning more calories than you consume)
- Liberate stored fat through lipolysis, which converts adipose tissue triglycerides into free fatty acids (FFAs)
- Burn the FFAs by shifting your body into fat-burning mode.
The bottom line? If you’re eating too many calories, you can’t create a calorie deficit, which essentially makes it impossible to lose weight. Running a mile burns about 115 calories, while a 12-ounce soda can contains 35 grams of carbs, providing 140 calories!⁶
You shouldn’t starve yourself to lose weight, but the point is to cut out unnecessary calories (like sodas and sugary drinks) instead of trying to “outrun” a faulty diet.
Evidence strongly suggests that combining appropriate diet and exercise delivers better, more sustainable weight loss results compared to diet alone.⁷ As long as you’re eating a balanced diet, exercise helps increase the calorie deficit, liberate stored fat, and burn more fat.
Daily walking or other moderate-to-vigorous activity paired with sensible nutrition is the best, most sustainable way to burn fat. You can aim for 30-60 minutes of activity per day to lose weight or more as time allows.
How Long Should You Exercise to Get Stronger?
Believe it or not, strength training is the least time-consuming fitness goal. You can get stronger with as little as two weekly sessions of 10-20 minutes or by doing a few reps at a time throughout the day.
When you train for strength, your body adapts in two primary ways: by increasing your central nervous system’s ability to recruit neurons and muscle fibers and by growing or building new muscle fibers.
The first type of adaptation is similar to building any motor skill. If you wanted to learn to juggle or walk on a slackline, you could make great progress with relatively short, low-intensity, frequent practice sessions lasting a few minutes or less.
The second type of adaptation can also occur following short, easy training sessions but is more likely to happen when you go heavy or perform reps explosively.
If you’re brand new to strength training, you can build strength without going heavy. Pick several upper body and lower body compound movements per workout and perform 1-3 sets of 5-10 reps per movement. This can take as little as 10-20 minutes twice a week, and you can make consistent progress for months or more.
When you hit a plateau on your easy sets of 5-10 reps, try using the “rule of 10” (a term coined by master strength coach Dan John). To do this, continue using multiple compound movements during each workout, increase the amount of weight when you can, and limit yourself to 10 total reps per exercise, for example:
- 5 sets of 2 reps
- 3 sets of 3 reps
- 2 sets of 5 reps
- Three total sets containing 5, 3, and 2 or 2, 3, and 5 reps
Can you get better results with longer training sessions? Yes and no.
Strength training for up to an hour, two to five times per week, may achieve faster results and build more muscle compared to shorter sessions but isn’t necessarily more sustainable or better overall. Both methods can work depending on your schedule and preferences!
How Long Should You Train for Endurance?
Your aerobic oxidative system is the energy system that predominates after about 60-90 seconds of sustained activity.⁸ Increasing your aerobic fitness requires constant activity for prolonged periods.
Along with other muscular and cardiovascular adaptations that occur with endurance training, your cardiac muscles remodel during aerobic sessions to be able to push more blood through your vascular system, an increase in what is referred to as “stroke volume.”⁹ Prolonged cardio sessions of 45-60 minutes or longer are highly effective at increasing stroke volume, which is reflected in a lower resting heart rate.¹⁰
Aside from stroke volume, it’s possible to increase most aspects of endurance in relatively little time, depending on what type of aerobic fitness you’re training for. In other words, training for a “short” 5K race looks quite a bit different from training for a marathon.
You can make meaningful progress for endurance events with as little as three days per week of training, typically spent like this:
- A fast day with less distance, usually including a form of intervals (often 15-30 minutes)
- A “tempo” run, ride, or swim at a sustained pace and medium distance (at least 30 minutes, sometimes up to an hour)
- A longer, slower “recovery” run, ride, or swim (usually 45 minutes to an hour and a half or longer)
Another tip that can help you get the most out of your endurance sessions is to use a heart-rate monitor to maintain the correct intensity. The 180-Formula is a method designed to calculate your Maximum Aerobic Function (MAF) heart rate.¹¹
To use the 180-Formula, subtract your age from 180, then subtract an additional 10 if you’re overtrained or recovering from an illness or injury; subtract an additional 5 points if you’re new, plateaued, or haven’t been training consistently. If none of these apply to you, use the original MAF number.
You would run your fast interval days at a heart rate at or just over your MAF, “tempo” runs at your MAF, and “recovery” runs about 10 beats per minute under your MAF.
If you’re thinking, “Whoa, that’s WAY too much math,” don’t worry! You can still build endurance with three weekly sessions lasting 30-60 minutes each, and you don’t need a heart-rate monitor. Spend most of your sessions at a pace where you can comfortably breathe through your nose or speak in complete sentences and you’ll know you’re in the aerobic intensity zone.