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You Might Be Working Out Harder Than You Need to Be. Here’s Why

Easy training 80 percent of the time is the perfect way to prepare for an endurance race. The only hard part is sticking with it.

By Eric ArnoldJuly 10, 2024


No matter who you are, how old or how fit you are, you know the feeling when you first start working out or return to exercise after a break. The endorphins kick in and each time you clip into the bike, set out for a run, or grab a dumbbell, you push a little harder. You’re chasing that feeling of accomplishment you had after your first workout and to go one proverbial step more. And then, one day, you realize you just can’t push your output, mileage, or reps any further.

If this sounds familiar, you’ve learned the hard way that fitness is an up-and-down journey, not a straight, linear progression of one achievement stacked atop the next.

There is a way, however, to avoid falling into this trap. It’s a training method experienced and amateur athletes rely on to ensure that those natural valleys our bodies experience are more like a dip into a shallow creek and not a freefall into the Grand Canyon. It’s called 80/20 training—essentially, doing light workouts 80 percent of the time and pushing yourself at a challenging level 20 percent of the time.

By training this way you can expect to avoid the most drastic effects of overtraining, have more enjoyable workouts, be less fatigued afterward, and reduce your risk of injury. You’ll also experience faster and steadier improvement on all the metrics that matter. And although 80/20 training is key for endurance runners, the approach can benefit almost any type of athlete—bikers, swimmers, rowers, you name it.

What is 80/20 Training?

Endurance athletes, in particular, subscribe to the 80/20 rule, often called 80/20 running by marathon runners or polarized training by cyclists. No matter where they are in their monthslong buildup to race day, whether they’re doing two miles or 20, 80 percent of the runs are easy and 20 percent are at race pace

The trick with 80/20 training is resisting the temptation to push hard and chase an endorphin-high or higher output. Peloton instructors often coach you to, “Listen to your body.” But with 80/20 training, it’s critical to listen to your brain. 

Through years of research on endurance athletes, Stephen Seiler, PhD an exercise physiologist at the University of Agder in Norway, discovered that most elite endurance athletes were spending the majority of their training time at a low intensity. His subsequent research, including a June 2024 study in Sports Medicine confirmed that coaches of world-leading athletes in Olympic endurance sports prescribed low-intensity training for 75 to 80 percent of all sessions. While more training is better, Seiler also found in his data that better training is better—meaning we should train more often, but not as hard as we think we should.

The Benefits of 80/20 Running

You don’t need to be a world-famous marathoner to reap the rewards of 80/20 training. Seiler and his colleagues found when recreational runners performed a 10-week polarized training program with roughly an 80/20 split, it stimulated greater training effects during a 10K run than runners who trained at moderately high-intensity.

“There are huge benefits for all types—from elite athletes to the everyday runner,” says Peloton instructor and experienced distance runner Becs Gentry. “Most people have a tendency to go out too hard for most runs, train around their threshold pace too often, and then get fatigued too soon in the training session or even the program.” Follow the 80/20 protocol, she says, and you can avoid that fatigue.

Researchers hypothesize that adopting an 80/20 training style may improve the quality of your higher-intensity sessions by preventing fatigue and staleness. It may also help to prevent overtraining or diminishing returns in your training, they write.

Those are benefits pretty much any type of athlete, recreational or record-setting, can get behind. And that’s really the best part of 80/20 training: Anyone can do it and start it any time, especially if the objective is to build endurance and achieve a particular race-day performance target. “Through certain training cycles I have used this method,” Becs says. “It absolutely has [helped], depending on my goal outcome.”

Who Should Use the 80/20 Training Method?

Anyone and everyone can and should use the 80/20 training method, whether you’re gearing up for an endurance bike race, a half marathon, a full marathon, a triathlon, you name it. If endurance is the name of the race, 80/20 training—along with strength training days, rest days, and stretching, of course—is the way to go. You’ll feel better after each training session and you’ll see the improvements in your pace all along the journey, right up to and on race day.

Of course, you certainly can use 80/20 training if you don’t have a race on the calendar. You will experience the same benefits over time. But it makes more sense to try the program if you know you have a specific goal in mind.

Let’s say it’s a half marathon in a few months, and you know you want to break an overall or minutes-per-mile pace. If you know your current baseline and what you want to achieve, 80/20 training can be the program to get you there. Without context or a target, 80/20 training can still be beneficial—but it’ll be harder to measure your improvement.

Beyond that, it’s important to resist the temptation to go 70/30, 60/40 or 50/50. That requires focus at first.

“I think people naturally end up liking to run at a slightly easier pace for as much as they can,” Becs says. And, as you see your improvement as you train, it gets easier and easier to stick to the program. Building your endurance over longer runs 80 percent of the time, she says, will leave you with “the energy to run hard for a smaller chunk of time—[that] means you have the impetus to crush it.”

How to Train Using the 80/20 Running Rule

Perhaps one of the best parts about developing an 80/20 training program is that it’s easy. Compared with other training styles, which all have their own merits, you don’t need to worry about  finding the right running cadence, learning to do the perfect tempo run, or incorporating Fartlek training. All those can be helpful, certainly, but they can contribute to information overload if you have a race on the calendar and a goal in mind. “Every training program is individual to the person completing it,” Becs says, adding that “most coaches would focus on one type of training schedule at a time.”

If you’re training on a Peloton Bike or Bike+ or Peloton Tread or Tread+ paired with a Bluetooth® or ANT+ compatible heart rate monitor, most of the information you need has already been collected for you. 

The most important data point you’ll need to figure out how slowly you should run on your “easy” days and how hard you should push the remainder of the time is your heart rate. That alone is key to setting your “easy” benchmark for 80 percent of your training runs and your “challenging” benchmark for the other 20 percent.

How to Calculate Your “Easy” and “Challenging” Paces

Using heart rate training zones is the simplest way to stay on track with 80/20 training. There are five heart rate zones, with zone 1 falling between 50 to 60 percent of your max heart rate and zone 5 between 90 to 100 percent of your max heart rate.

During your “easy” workouts, you should aim to keep your heart rate in zone 1 or 2. (You can learn more about zone 2 cardio here, a popular training method in itself.) If your heart rate creeps up into the third zone, you’re pushing too hard. Your challenging workouts will likely be in zone 4 or 5.

From there, you just need to match your lower heart rate zones to your training plan. For instance, if you’re training for a half marathon, in your first couple weeks you might be running three miles, five days a week. That means on four of your runs, you should keep your heart rate in those first two zones. 

On your fifth run of the week, you’ll try to maintain your ideal race-day pace. While this is your “challenging” workout, that doesn’t mean you’re going all-out—it means you’re trying to hit and maintain the per-mile target you have in mind for the actual race. For some people that will be zone 3, others zone 4, and some may even be in zone 5.

The strategy is the same when you increase to, say, four miles on each run, five days per week. On four of the runs, keep your heart rate low; on the fifth, just try to hit that race-day pace again. Same goes if each training run is eight or ten miles. Making sure your heart rate is staying in those first two zones is the best way possible to ensure that your slow, easy pace for 80 percent of your runs is actually slow and easy, no matter the distance.

All the while, you should take note of your minutes-per-mile pace in both your “easy” and “challenging” training sessions. Over time, you’ll find that you can keep your heart rate low even as your “easy” pace increases.

As the distances for each training session increase and race day approaches, keep an eye on your data and see where your heart rate was on those race pace training sessions, too. This information will be vital on race day, because you’ll want to make sure your heart rate isn’t ticking higher than the zones you were hitting on those more challenging runs. If it is, that’s a sign you’re running too fast and might burn out before the finish line.

Remember, the key to experiencing the benefits of 80/20 training is simply sticking to it, certainly—but doing it well. Be a bit nerdy and take note of your heart rate and per-mile pace after each run. Do that, and you’ll avoid the most challenging aspect of any type of training: fatigue. 

“Implementing the 80/20 can help all levels of runners mitigate this if they follow it well,” Becs says.

Looking to switch up your routine?


Featured Peloton Instructor

Headshot of Peloton instructor Becs Gentry. She's wearing a light blue Peloton two-piece workout outfit and smiling with her arms crossed.

Becs Gentry

Becs joins Peloton from London as an accomplished distance runner and coach who uses the sport as a way to explore the world. You’ll leave her class smiling and proud.


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