Let’s be honest: It can be tempting to run on level ground with no incline. Flat routes and tread belts let you simply cruise along at a steady pace with a steady effort. Running is hard enough already, right? Well, deliberately seeking out an incline to run up again and again with some hill repeats can make you an even better runner.

“Hill repeats are something most runners will encounter in training at some point, whether it's by design or by accident!” says Peloton instructor Susie Chan. “If you run off your Peloton Tread, it's not always flat routes outside.” 

Running uphill naturally amps up the intensity, which is why so many pros make dedicated hill sprints a regular part of their training program. “Hill repeats are a great way to improve your running fitness and strength,” Susie says. Read on to learn what you can get out of this workout, and how to do it effectively. 

What Are Hill Repeats?

Hill repeats are a running workout that’s just what it sounds like: Repeated bouts of running up a hill. “They are simply running up and down elevation repeatedly in your run,” Susie says. 

That can mean hitting the same hill (or tread incline) over and over, or choosing a route that has you running on hill after hill. “Often for simplicity people choose to run up and down the same hill,” Susie says, “but hill repeats can also be taking a deliberately hilly route with various gradients to tackle.”

Either way, the typical approach is to run hard up the hill, then recover with a light jog or walk on the way back down. This is the opposite of how you’d approach a race, where you’d slow down on the uphill to conserve energy. But the focus of this workout is to use the challenge provided by an incline to become a stronger runner. 

The Benefits of Hill Repeats 

It’s no secret that hill sprints are not an easy exercise. But the benefits of hill runs might convince you to regularly add them to your training plan. 

They Can Build Strength 

Thanks to gravity pulling you downward, your muscles quickly feel it when you take on a big incline—but the struggle pays off. “Hill repeats are a great way to strengthen your legs,” Susie says. “They work your legs in a way flat running does not.” Charging upwards will fire up your calves, hamstrings, quads, inner thighs, and glutes. In particular, research shows that the vastus muscles in your quads are activated 23 percent more and the soleus (in the calf) is activated 14 percent more compared to when you’re running on level ground.

They Can Make You Faster

Susie says hill repeats are a “fantastic way” to become a faster runner. “If you are training your body to power up a hill, when you take your running onto a flat course, you will really feel the benefit of the training!” she says. Many people even call hill repeats “speedwork in disguise” because even though your pace might not pick up much (if at all), the intensity revs up as you climb each hill. And that can add up to faster paces: One 2021 study showed that hill running efficiently increases aerobic capacity, AKA your VO2 max, or the amount of oxygen your body can use during exercise. 

They Can Help Your Form

When we run up a slope, research shows we’re more likely to use quicker steps that land on our forefoot or midfoot. This faster running cadence can help give you a more efficient running form that keeps you from overstriding, which might not only improve your running performance, but also help protect your body from injury. 

They Make You Feel Superhuman

Sure, you might be huffing and puffing when tackling that elevation. But getting to the top of each hill sprint is a powerful feeling. “Go into it knowing that it will be challenging—you are supposed to feel like you are pushing yourself!” Susie says. The upside? “You will feel so accomplished at the end.”

How to Get Started With Hill Repeat Workouts

Although they’re challenging, hill repeats aren’t just for advanced runners. Even beginners can tackle them with the right approach. Here’s how. 

How to Do a Hill Repeat

The first step for running hill repeats is the same as any other workout: a warmup. “Run at least a mile prior to any reps,” Susie says. 

She also suggests going into any hill repeat workout with a plan, rather than just trying to wing it. Test out your hill before starting the workout to get a feel for it, and then set a goal. “Find your hill, and decide before your first rep how many you will do,” she says. “I would suggest starting at four and then adding more the next time.” Remember: The more reps you do, the harder the workout will be. 

However many intervals you do, focus on maintaining good form on each one: “Stand tall, use your arms to drive you up by propelling your elbows back, shorten your stride, and try to breathe evenly,” Susie says. Once you reach the top, keep moving—walk or jog back down to the start to get yourself ready to go again. On a treadmill, you can lower the incline and slow down to an easy pace. 

Does Length or Steepness of the Hill Matter?

There is no one ideal length or steepness for hill repeats. “It depends on what your goal is and your current fitness level,” Susie says. She simply recommends setting yourself up for success by choosing a distance and gradient that you can realistically tackle. “So perhaps it is a lower incline and slightly longer, or steeper and shorter,” she says. “I like to find something which will be longer than 30 seconds to run up but not more than two minutes.”

Hill Repeats Pace

Because the grade can vary, hill repeats are typically done based on effort, rather than a predefined pace. So a coach will tell athletes to hit, for instance, their 5K effort—or how hard they could race 3.1 miles—instead of their 5K pace. When you’re new to doing hill sprints workouts on a treadmill, it’s best to start off conservative on the first interval, and then dial up the speed as you go until you find the right effort level. 

Should I Be Running Downhill as Well?

During hill repeats, runners will typically use the downhills as a chance for recovery to get ready to tackle the next uphill interval. That could look like an easy jog or a walk back down to the starting point. Don’t try to run hard downhill, too—that turns it into a different kind of workout because you won’t have enough energy to run hard uphill intervals. 

What to Do If You Don’t Have Hills Near You 

Don’t live near a hill? “You can do hill reps with exactly the same benefits on your Tread,” Susie says. “The effect of running at incline is just as good on a treadmill or outside, especially if you are working on your run speed.” On one of Peloton’s Treads, you can take a hill class that’s already designed to give you a challenging uphill workout (and will include auto incline adjustments based on the instructor’s cues). Or if you prefer to do things by yourself, you can design your own hill sprints workout with a set time and incline.  

The only thing you’ll miss out on is the downhills, Susie says. “These are a great way to get those quads strong,” she adds. That’s why, if you’re training for a hilly race like the Boston Marathon, she suggests doing some of your hilly training runs outside. “You will need to condition those legs to be strong on downhills also,” she says.  

Sample Hill Repeats Workout

There are many ways to do a good hill repeats workout. Here’s a basic idea of what one might look like: 

Warm-up: Run one mile at an easy pace to get your blood flowing. Then, take a few minutes to do some running warm-up exercises, like leg swings and high knees to make sure all the right muscles are activated and ready to go.

Workout: Run up a moderately-steep hill for 45 seconds at your 5K race effort. (On a treadmill, set the incline to somewhere between five and 10 percent). Turn around and jog downhill or simply lower the Tread incline to recover before immediately repeating. Start with four reps, and work your way up to 10. 

Cooldown: Finish up with one mile at an easy pace. Then stretch out those muscles after so they don’t tighten up on you.       

The Takeaway

Hill repeats are by no means easy, but they can be a powerful way to boost your strength and speed as a runner. “Mentally get ready! It does feel tough,” Susie says. Start with just a few reps, and add more as your body gets used to the challenge. With consistent practice, you’ll see a payoff during your everyday runs—whether they include any hills or not.