Sprints are short bursts of running in which you go as hard and as fast as you can for abbreviated amounts of time. The idea with sprinting is to expend all of your energy and muscle strength to tap out your body’s resources.
Basically, it’s power running.
Since sprinting is just another form of running – albeit a more strenuous form – it provides many of the same benefits as endurance running:
- Strengthening of leg (and, to a lesser extent, core) muscles
- Strengthening of bones
- Improved mental health
For this article, we are focusing on the things that set sprinting apart from endurance running and make it a great exercise to add to your regimen even if you already run for distance.
HIIT vs Running
When you’re talking about sprinting versus running, you’re really talking about HIIT (high-intensity interval training) versus LISS (low-intensity steady state) cardio.
This distinction between low- and high-intensity is what gives sprinting its distinctive benefits and why you should incorporate sprinting along with running or another steady state cardio instead of replacing those exercises.
Think of sprints like weightlifting and other strength exercises. Sprinting tears and builds muscle and puts strain on your bones and joints. Due to this, you shouldn’t do them every day. “Off” days are great days for steady state cardio.
Your metabolic rate determines how quickly you burn calories. Like other HIIT exercises, sprinting increases your metabolic rate more than steady state exercises, including traditional running.
Studies have shown that two minutes of sprints has about the same effect on metabolism as 30 minutes of endurance running. And you don’t have to do those two minutes all in a row. Four 30-second sprints (or eight 15-second sprints) has virtually the same impact.
Two minutes of sprinting provides your body with roughly 24 hours of “afterburn” or increased metabolism and calorie-burning post-workout.
Cardio exercise uses carbs for fuel. Studies show that HIIT exercises, like sprints, require so much energy so quickly that they bypass carbohydrates in the body and dig into fat stores instead.
This means sprints burn a lot more fat than regular running, most importantly reducing abdominal fat, which is a major risk factor for disease, including heart disease and type 2 diabetes.
Sprinter Muscle Mass
Sprinting is a power workout. Unlike endurance running, which has mostly cardio benefits and provides more toning than muscle gain, sprinting mostly burns fat and builds muscle. Here’s how it works:
A sprint is an “explosive” body movement that requires a lot of force very quickly. Explosive movements like this use Type II muscle fibers, also known as fast-twitch muscle fibers. These muscle fibers contract more forcefully than Type I, or slow-twitch, fibers, which is what your body primarily uses for slower, less intense movements.
That means, when you sprint, more muscle fibers are engaged and torn than when you run at a slower pace. The more tears you get in muscle fibers during a workout, the bigger your muscles become. But the more tears you get, the more time your body needs to heal, which is why you shouldn’t do sprints every day.
Sprinter Body/Sprinter Physique
The three benefits above – increased metabolism, higher fat-burn, and greater muscle mass – combine to create what is known as sprinter’s body.
Over time, sprinters tend to develop muscular appearances, which is mostly noticeable in leg and ab definition. Compared with long-distance runners, sprinters tend to have larger muscles and look leaner.
Don’t be fooled, though. Sprinting will not give you muscle definition all over your body. Sprinters with noticeably muscular upper halves do upper body workouts to compensate.
Can you get abs from sprinting?
Yes and no.
Everyone has abs. For most people, “getting abs” isn’t about building more muscle, but about getting rid of the belly fat that covers ab muscles up.
As previously stated, sprinting is an excellent fat-burner and can make abs more visible.
But belly fat is stubborn. Getting rid of it takes full-body training and a healthy diet. It’s unlikely you’ll get a six-pack from sprints alone.
Will sprints make my legs bigger?
Short answer: They might.
Long answer: It depends on how much fat you have on your legs when you start.
If you’re carrying excess fat on your legs, sprinting will most likely make your legs smaller at first as the fat burns away. But at the same time, your muscles will be growing underneath.
For people who are already muscular or overweight, sprints may not change leg size very much. Though, those carrying fat will see that fat converted to muscle.
For thin people with less muscle, sprints may very well increase leg size.
Will sprinting make my butt bigger?
Once again, it depends.
Sprints will burn fat first, which, for many people, will decrease butt size. Though, some thinner people may see an increase in butt size due to muscle development.
All people who are just starting sprints may experience their butts looking bigger. Sprints tone the glutes, and they do it pretty quickly, which can lift the butt and make it stick out more.
This butt lift is especially likely if you’re doing sprints up hills, which puts more focus on the butt muscles.
How often should you run sprints?
No more than three times per week, with 24 to 48 hours of rest in between.
Pay attention to your body. If you are slowing down or unable to do as many sprints per session, you’re not giving yourself enough time to heal.
Calories Burned Sprinting
Sprints burn around 20 calories per minute for a 150-pound person who is going all out. That’s twice the amount of calories burned while jogging.
While calories burned varies by weight and effort, in general:
1-minute sprint = 20 calories
Muscles Used in Sprinting
When you sprint, you use all of your leg muscles:
- calf muscles
You also use:
- your glutes (more so during hill sprints)
- your core muscles (both abs and obliques)
Along with sprints’ other great benefits, they are also a massive time-saver. You can expect to burn twice as many calories and get four times the after-burn from sprints than from traditional running.