If you’re looking to build muscle, you likely don’t do the same strength training exercises with the same weights over and over (and over) again. Instead, you mix it up—by following a split program or changing the load you’re lifting. The same standard should apply to your runs. To become faster and increase your anaerobic threshold, sometimes you need to throw a sprint workout into your running routine. 

What Does it Mean to Sprint, Exactly?

Just like the definition of a “slow run” or an “easy ride” can vary depending on whom you ask, what qualifies as a “sprint” is relative. 

A sprint is generally considered running “all out” for as long as you can, followed by a recovery period, says Nina D. Whorton, a physical therapist at FYZICAL Therapy & Balance Centers Franklin in Franklin, North Carolina.

The pace of a sprint is going to differ for every runner, adds Peloton instructor Jon Hosking. Generally, this speed should be your all-out effort—as close to maximum exertion as possible over a short distance or time. 

“We’re looking for a physical effort that can only be sustained for anywhere between a few seconds up to around two minutes,” says RJ Williams, a physical therapist for FYZICAL Therapy & Balance Centers. And it’s not exclusive to elite athletes or those in the midst of race prep. “Sprinting can be for nearly anyone, at any age,” he says “Intensity is relative. Your maximum effort will evolve as you become more physically fit.”

The Benefits of Sprinting

“Sprint training is hugely beneficial for any runner, but particularly those looking to diversify and vary their running workouts whilst building more explosive speed and running power,” Jon says.

If you’re prone to falling or injuries, are currently recovering from an injury, or have any preexisting cardiovascular difficulties, make sure to take the necessary precautions—and potentially steer clear of sprints. And before you break out into a quick pace, make sure to establish a base of cardiovascular fitness. You should be comfortable with your running form, able to hold a slow and steady jog, and have a measured breath. 

Here of some of the key benefits of sprinting:

1. It’s Efficient

Sprinting allows you to “reach high levels of energy expenditure in a short space of time,” Jon says. If burning calories is a goal of yours, this type of workout can help you do that in a shorter amount of time, compared to other running workouts. 

2. It Will Build Your Power, Stamina, and Speed

“Anyone who wants to fuel their metabolism, get faster, or build stamina and power will benefit from sprints,” Whorton says.

Unlike a marathon run or a long, steady bike ride that employs your slow-twitch (type I) muscle fibers, sprinting activates your fast-twitch (type II) muscle fibers that help you produce power and force. By sprinting, you challenge your fast-twitch muscle fibers, which should lead to improvements in your overall speed and running performance over time, Jon says.

Sprinting increases the strength of those fast-twitch muscle fibers and coaches your cardiovascular system to be more efficient at circulating blood and oxygen to your muscles. This benefits your heart, lungs, and endurance, Williams says. “Our goal with sprinting is to produce maximum power for as long as we can.”

3. It Offers a Mental Boost 

Whether you’re running a 10K, half marathon, or full marathon, “your brain can get in the way,” Whorton says. Sprinting gives you a chance to practice pushing past the mental “wall” that you might hit come race day. Since this type of workout is so vigorous, it can act as a vivid piece of evidence that you can push through challenges.

Another reason to run at a more rapid pace? The rush. “Sprinting is arguably more exhilarating than steady-state cardio, and is likely to induce a rush of endorphins,” Jon says. “[It can be a] great stress-reliever, and an amazing way to help focus the mind.”

4. It Can Increase Your Anaerobic Threshold

Your “anaerobic threshold” refers to the highest level of exercise intensity you can handle for a prolonged amount of time without lactic acid (lactate) building up in your blood. Past this point, you’ll start to experience a significant amount of fatigue. As a general rule, the more you train at higher intensities through interval and sprint workouts, the higher your anaerobic threshold. 

5. It Can Increase Your VO2 Max

Your maximum aerobic capacity is also known as your VO2 max, and “running at a higher intensity has a huge impact on improving your VO2 max,” Jon says.

How to Warm Up Before Sprint Workouts

“Because sprinting is at maximum or near-maximum effort, it’s vital that you prepare your muscles, heart, and lungs to perform at their best,” Williams says. Aim to complete a five- to 10-minute warm-up that includes dynamic stretches before any sprint workout.

“These [types of stretches] fire up and activate the specific running mechanics needed to perform sprints more effectively,” Jon says. “They'll also help bring about a rhythm to your strides, which is key for sprinting.”

Start with a five-minute jog, then perform these sprint-specific warm-ups for one minute each:

Try to crank up the intensity with each move, Williams suggests. “Considering that your sprint reps should land around a nine to 10 out of 10 effort, start by performing a few reps at around a four or five out of 10, and then begin bumping up that intensity until you are ready to perform your work.”

Sprinting on the Road vs. Indoors: Key Differences

There are pros and cons to both indoor and outdoor workouts. Sprinting on a treadmill allows you to control more of the variables: distance, time, terrain, weather conditions, and climate. It also enables you to monitor your speed more closely, Jon says. 

“It also forces you to sustain that speed even when mentally you’d want to pull back, keeping you honest,” Williams adds.

That being said, you may personally prefer the sensation of being on the trail or road. Sprinting outside also allows you to naturally dial in your effort levels. Rather than being locked into a selected speed, you may surprise yourself by setting a new personal record for time or distance.

There’s no wrong choice when it comes to sprinting outdoors or indoors. Try both and take note of how you feel mentally and physically after to choose your preferred sprint workout location. Feel free to mix and match depending on your mood and the conditions.

4 Sprint Treadmill Workouts to Try

Start by adding one sprint workout to your routine per week, before building up to two to three sessions a week. (Note that any number above that may increase your risk for injuries, overtraining, and extreme muscle soreness.)

There are four variables that can make each sprint workout different, Williams says.

Sprint workouts require a lot of effort and focus, but don’t forget to tune into your body. If you notice any discomfort, dial things back or take a break. And as with any sport or physical activity, consult with your doctor or a physical therapist prior to doing it. 

Looking for a place to start picking up the pace? The following Peloton Tread workouts will coach you through the most popular (and effective) types of sprint workouts. 

1. Tempo Runs

Build your speed and endurance during these intense workouts that involve running at or just below your goal race pace for a stretch of time. 

2. Interval Runs

During these sprint workouts, you’ll increase your pace or the incline you’re running on to make your heart rate soar, before catching your breath during a well-deserved recovery period. You’ll continue to repeat this sequence throughout. 

3. HIIT Runs

If you’re crunched for time, one type of interval run you may want to explore is a high-intensity interval training (HIIT) run, in which you’ll clock a maximum effort followed by a recovery period. 

4. Hill Runs

Admittedly tough for even distance athletes, hill runs involve fast-paced intervals performed at difficult inclines to build your power, speed, and endurance. Long, steady hills are all about endurance, while shorter, steeper hills deliver gains akin to a plyometric workout, Whorton says.