Why is low intensity training so important for performance?

Young woman running in forest
The science shows that if you’re seeking to improve performance, you’d do well to shift down into low gear on a regular basis with low intensity training (Image credit: Stanislaw Pytel)

In a world obsessed with FKTs and personal bests, the idea of low intensity training might cause some athletes to wrinkle their nose. Why bother splashing out on a pair of the best trail running shoes and a Garmin watch to track your increasingly impressive metrics if you’re just going to go for a jog, you might wonder? And yet, the science shows that if you’re seeking to improve performance, you’d do well to shift down into low gear on a regular basis. Doing so can improve your stamina and ultimately place less strain on your joints and soft tissue. Read on to learn more about what low intensity training looks like and why it’s a good idea. 

Woman checking sports watch during run

Keeping your heart rate at 50% of your VO2 max can have a big impact on your performance (Image credit: Getty)

What is a low intensity workout? 

When it comes to exercise, intensity might seem to be rather a subjective quantifier – for me, any run longer than 10k seems pretty intense, but for my friend Tara, an ultrarunner, that’s practically a recovery run. So “intensity” might be a bit of an individual experience, based on your current level of fitness and what activity you’re doing, but there are actually three defining characteristics that make a workout low intensity no matter who is doing it:

  • You maintain a steady heart rate (so, no intervals then)
  • You workout at about 50% of your VO2 max
  • You workout for a sustained period of at least 30 minutes

Obviously, this could apply to lots of different activities then, from a long, slow jog to a dynamic yoga practice, but the following are some typical low intensity workouts:

  • Brisk walking
  • Moderate hiking
  • Slow jogging
  • Lap swimming
  • Cycling through flat or rolling terrain
  • Dynamic yoga such as Vinyasa
  • Rowing
  • Elliptical workouts
  • Slow weight lifting or resistance training

In any of these activities, you could use a heart rate monitor to keep an eye on your performance, but there are other ways to keep yourself from switching into high gear. You should in theory be able to hold a conversation, so you won’t be breathing extremely hard or necessarily sweating profusely (though we all sweat in different quantities). Keeping these markers in mind, you’ll be able to choose appropriate hiking and running trails that aren’t too steep, or look for sections of flatter long distance hikes or road rides rather than always going for the hill climb. As time goes by, your fitness will improve, and you will need to up the intensity of your workouts by choosing more challenging terrain or picking up the pace a little in order to reach 50% of your VO2 max. 

Man hiking on cliffside trail

Choose appropriate hiking and running trails that aren’t too steep (Image credit: John Crux Photography)

What are the benefits of low intensity training? 

High intensity training, such as HIIT workouts and ultramarathons, are hard on your cardiovascular and musculoskeletal systems. That’s why you don’t want to do HIIT workouts more than a couple of times a week, and why you need to rest for at least a week after an ultra event, to offset the health risks. Low intensity training puts much less stress on your body, and a long term study by Fukuoka University published in 1992 found that 60 minutes of low intensity training 3 - 5 times a week actually improved VO2 max, improved HDL cholesterol levels and lowered blood pressure, all without modifying diet.

Of course, those latter two benefits are compelling for anyone looking to improve their health, but for athletes, the improvement to VO2 max is the most seductive benefit, because that means that low intensity training will ultimately allow you to go further, for longer. The fact that you can build stamina while placing less strain on your joints is naturally going to be another appealing argument for turning down the dial on the regular – if you can improve your fitness without increasing your risk of injury, you’ll improve your longevity as an athlete, too.

Now it’s true that a lot of the studies on low intensity training have been performed using elderly subjects or those with chronic health conditions rather than on athletes, but regardless of the research, there remains the simple fact that, for most of us, a low intensity workout is simply easier to commit to. The HIIT workout, half marathon or fastpacking your way over three 14ers in a single day all require a certain degree of mental commitment and usually take quite a bit out of you. But a 45-minute jog or three-mile walk can usually be accomplished even when you’re a bit tired, making you more likely to lace up those hiking boots in the first place and be able to commit to several low intensity days a week. In fact, these workouts can actually be used as active rest days between high intensity workouts, though after a big race or workout, total rest is often the best medicine.

A runner tying their shoelace on the trail

You're more likely to have the motivation to lace up for a low intensity workout three times a week (Image credit: kupicoo)

Can you build muscle with low intensity training? 

It’s well known that in order to increase muscle mass you need to place stress on your muscles, so if that’s your goal, you might be wondering if low intensity training places enough demand on your muscles to make a difference? Of course whether and how much muscle you build really depends on what you’re doing, but a 2012 study published in the Journal of Applied Physiology did find that participants saw an increase in muscle mass when they implemented low intensity resistance training, so yes, it’s possible. 

Person lifting kettlebell at gym

Slow weight lifting and resistance training can help build muscle (Image credit: Getty)

Do low intensity workouts burn fat? 

As we explain in our article on heart rate zones, low intensity exercise does indeed burn fat. According to the Cleveland Clinic, though you’re burning fewer calories at this lower intensity level, most of the calories you’re burning are from fat, whereas during high intensity training your body relies on carbs for energy. That said, per minute of training, you’ll still burn more fat during high intensity training than low intensity training, so you’ll want to do low intensity work for longer periods of time, and interspersed with high intensity days, if burning fat is your goal.  

Man hiking with pine trees in the distance

If you want to improve your performance then, and you’re already doing high intensity workouts, try to balance those high intensity days with one or two low intensity days in between (Image credit: Garmin)

How often should you do low intensity workouts? 

If you’re starting from scratch, two or three days a week is a good place to begin, whereas if you’re already active, the low intensity nature of these workouts means that you can’t very easily overdo things, though anything is possible. You’re much more likely to overdo high intensity training, or rely too much on high intensity training with total rest days in between. If you want to improve your performance then, and you’re already doing high intensity workouts, try to balance those high intensity days with one or two low intensity days in between. This helps you to keep improving your fitness while you’re recovering. 

Julia Clarke

Julia Clarke is a staff writer for Advnture.com and the author of the book Restorative Yoga for Beginners. She loves to explore mountains on foot, bike, skis and belay and then recover on the the yoga mat. Julia graduated with a degree in journalism in 2004 and spent eight years working as a radio presenter in Kansas City, Vermont, Boston and New York City before discovering the joys of the Rocky Mountains. She then detoured west to Colorado and enjoyed 11 years teaching yoga in Vail before returning to her hometown of Glasgow, Scotland in 2020 to focus on family and writing.