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Why you should be adding sprints to your workout routine—even if you hate running.

Essentially, all you need to start a running program is a decent pair of shoes and the appropriate attire, making it one of the most popular forms of working out. The body burns approximately five calories of energy for every liter of oxygen it consumes; therefore, if the goal of a movement program is primarily weight-loss, then running becomes an effective solution, because it requires a lot of oxygen to fuel muscular activity. Whether inside on a treadmill or outside on a trail, running is an efficient form of movement that can help improve your body’s ability to use oxygen, helping you to become a more effective calorie-burning machine.

The good news is that if you really don’t like to run then there are a number of other options that can help you burn calories. However, even if you are one of those people who find joy in running and have fun with it, it does get a bit, well, repetitive. As enjoyable as it may be to lace up your favorite pair of shoes, hit play on a motivating playlist and become lost in the cyclic action of left-foot, right-foot, repeat, at some point, you are probably interested in learning new ways to make your running workouts more interesting. Whether pursuing a specific goal, like faster foot speed, or improving aerobic capacity (the ability to use oxygen to fuel activity) or simply want to change up your workouts a bit, consider taking a page from the sports world and adding sprints to your running workouts.

The science of running

First, a little physiology lesson. It’s important to note that there are two general types of muscle fibers in your body: slow-twitch and fast-twitch. Slow-twitch fibers use oxygen combined with fatty acids to provide the energy for contractions. Because they are efficient at using oxygen to help fuel activity, slow-twitch fibers are often involved with endurance activities like distance running.

Fast-twitch fibers, on the other hand, use the other source of energy in the body, carbohydrates (called glycogen once it is stored in muscle cells), either with or without oxygen, to fuel muscle activity. Whether or not oxygen is used in the process of converting glycogen to adenosine triphosphate (ATP), the actual chemical used to fuel muscle contractions, there is only a finite supply of it stored in muscle cells, so it is depleted rather quickly.

As the names suggest, the process of converting glycogen to energy takes less time in fast-twitch fibers than converting fatty acids to energy in slow-twitch fibers. When your body needs energy quickly to fuel explosive activity, it engages the fast-twitch fibers to do the work. Fast-twitch fibers are larger than slow-twitch fibers and play an important role in the definition of particular muscles. The primary benefit of adding sprints to your running workouts is that you can engage more of your fast-twitch fibers, which can help you burn more calories while simultaneously improving definition of your leg muscles.

Running for distance is a great way to train the slow-twitch muscle fibers, which are primarily responsible for converting oxygen and fats to energy. Running at a steady pace for a distance or time can improve the efficiency of your slow-twitch muscle fibers, but can often leave many of the fast twitch fibers uninvolved in the activity.

However, it is the fast twitch muscle that are most responsible for enhancing muscle definition. A quick search can produce the winners of the men’s marathon, Eliud Rotich of Kenya, and the men’s 100-meter sprint, Usain Bolt of Jamaica, in the 2016 Summer Olympics. Notice a difference between these two athletes? Bolt has a lot of well-defined, lean muscle, while Rotich, even though he is a great athlete, is pretty much legs and lungs.

Why you should be sprinting

If you want to improve muscle definition in your legs, thighs, hips and rear end, sprints should be an essential part of your workout. Here are six other reasons why you should consider making sprints a regular component of your overall workout program.

Active-aging benefits

If toned, sculpted legs aren’t a reason to start sprinting, consider the active-aging benefits. During the aging process, type II muscle fibers can atrophy, which can contribute to the loss of muscle mass (called sarcopenia). High-intensity training like sprinting is a great way to recruit type II muscle fibers and maintain muscle mass throughout the aging process.

Hormones that build muscle

Long-distance running, especially for longer than an hour at a time, can increase levels of cortisol, which, among other uses, can convert protein to fuel, thus reducing the body’s ability to build new muscle tissue. Sprinting, however, can promote the release of the hormones that help build muscle. Another active-aging benefit of sprinting is that it creates the metabolic and mechanical stress that signals the release of muscle-building hormones like testosterone (T), human growth hormone (HGH) and insulin-like growth factor (IGF) that are used to repair damaged muscle fibers and build new tissue. Adding sprints to your workouts can help you maintain or increase your levels of calorie-burning, lean muscle mass, which will help you to achieve a more youthful appearance.

Calorie burn

Doing a series of sprints is an effective way to achieve the benefits of high-intensity interval training (HIIT), which includes burning a lot of calories in a relatively short period of time. It also helps you burn more calories after your workout is over, an effect known as excess post-exercise oxygen consumption (EPOC).

Aerobic efficiency

HIIT can be effective for burning calories, but it can also help improve overall aerobic efficiency (your ability to use oxygen for fuel). If you do enjoy running in distance races like ten kilometers, half-marathons or marathons, then sprint training can help improve aerobic capacity while limiting the total distance you have to run, helping to reduce the risk of an overuse injury.

Range of motion

Sprinting is a form of dynamic flexibility. Running for distance uses a relatively short running stride, while running for speed requires a greater range of motion from the ankles, knees, hips and shoulders. The explosive arm and leg action required for effective sprinting results in greater joint range of motion of the involved body parts.

Reduces injury risk

Sprinting improves the extensibility of the involved muscles, fascia and connective tissue, which helps to reduce the chance of injury from muscle strains. Flexibility refers to the ability of a joint to move through a complete range of motion, while extensibility is the ability of a muscle to easily lengthen and return to its original starting position. The explosive actions required for sprinting improves the structures of the involved tissues, which helps them to become stronger and more resilient and thus less susceptible to injury.

Gassers. Suicides. Sprints. Whatever you want to call them, they are no fun. But if you played any sports when you were growing up, sprints were probably an essential part of your team’s training routine. You may have bad memories of an obnoxious coach forcing you to run sprints until you were gasping for breath. Once you stopped playing sports you probably swore a solemn oath that you would never, ever do another sprint.

If running is a regular part of your weekly fitness regimen then you should probably consider going back on your oath and giving sprints another chance. The good news is that instead of a loud-mouth coach yelling at you to run until you’re winded, you get to choose the distance to run, the number of reps and, most importantly, the amount of rest between sprints.

If this list has piqued your interest in sprinting, a great workout to help you get started is listed below. Keep in mind that sprinting places a lot of mechanical stress on your muscles and connective tissue, so you should perform a complete warm-up that starts with slow, rhythmic movement and gradually progresses to rapid, explosive actions. For a frame of reference, Usain Bolt, the current Olympic champ for the Men’s 100-meter sprint, can complete the race in less than 10 seconds, but will spend more than 45 minutes warming up for that one, single event.

This might not seem like a lot of exercise, but if done correctly you will definitely feel the results. Allow some time (three to five weeks) for your body to adapt to the high intensity work before adding more distance or reps. Have fun—and remember: When you’re in charge of your own sprints they may turn out to be much more enjoyable than you remember.

Sprint workout

Dynamic warm-up

Do two to three sets of each movement.

  • Body-weight squats
  • Side lunges
  • Push-ups

Agility drills

Ten to 15 meters outdoors on a court, or 20 seconds on a treadmill. Perform three times each.

  • Hurdle walks: Lifting up foot like stepping over a hurdle
  • High knee jogs: Slow pace, lifting knee high as possible
  • Lateral shuffle (each direction)
  • Backpedal
  • Forward skips
  • Lateral skips

Sprints

Start with three sets of five, then progress to five sets of seven.

Do active rest (walking) for 30-45 seconds after each 100 percent effort sprint; actively rest for two to three minutes after each set of five sprints.

  • On a treadmill: 15 seconds of all-out effort. Other options are to sprint on a basketball court from baseline through the opposite foul line, or to sprint on a football field for 50 yards (from the end zone to 50-yard line)

Once three sets of five is easy, add reps to seven, then start adding sets returning to five reps.

Example: After three sets of seven, progress to four sets of five and gradually add reps until you get to four sets of seven, then start with five sets of five.

Cool-down

Static stretching: Hold each stretch for 45 seconds, complete two times per leg.

  • Hamstrings: Hold left leg straight out front with right knee bent, reach for left foot, alternate
  • Quadriceps: Pull heel of right foot to right glutes, alternate
  • Calves: Lean forward while extending right leg straight back, keep right heel pressed into ground, alternate

Check out these five running recovery mistakes you could be making.

Photo credit: YakobchukOlena, Thinkstock