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There’s no better exercise. Sprint interval training is by far the most effective way to transform your body in the least time.

It doesn’t just strip away body fat. Interval workouts build muscle, give you nice legs and abs, and fix your metabolism. They also improve your energy levels, boost motivation, and make everything in life a little sharper.

Despite the abundant reasons to make sprinting a habit, it’s likely that unless you are a hardcore trainee or athlete, you aren’t sprinting as often as you should. This is a mistake.

Some form of interval training is valuable for everybody even if hitting the track for a few speedy 100-meter repeats isn’t your cup of tea. Let us convince you.

First, you must understand what sprint interval training is: All it requires is that you do intense but short bursts of exercise interspersed with rest.

You can do interval bursts by running, cycling, swimming, weight training, body weight exercise, running stairs, walking, or any other mode in which you work hard and then recover.

Second, interval training can work for everyone, but you must adapt it to your needs:

  • If you are completely out of shape, start with something as simple as run-walk intervals or moderate cycling intervals since even those will “feel” like a sprint.
  • Fit trainees who want to get a bit more shredded can benefit from both moderate and all-out intervals with varied rest depending on the interval length you pick and your conditioning level.
  • The average high school athlete will benefit the most from all-out short intervals with very little rest.
  • If you are elderly, overweight, or have conditions like high blood pressure, diabetes, or arthritis, you might start by walking briskly for 3 minutes interspersed with 2 to 3 minutes of slower, more casual walking.

Here are 12 benefits you can get out of interval training.

#1: Better Abs

A lot of people want leaner, cutter abs, but they waste their time training sit-ups and other core exercises that are completely useless.

Here’s the deal: Chances are, if you want better abs, you need to lose the fat that is covering them up. We can work on filling out your six-pack after the fat comes off with a serious weight training program, but intervals are the best way to shrink your love handles and burn belly fat fast.

This is because intervals literally repair your metabolism, by reducing inflammation and forcing the body to improve it’s ability to use and burn energy.

#2: Leaner Legs

Intervals don’t just make you leaner around the waist. They burn fat all over the body making them your best choice for fat loss. Period.

Of course, lean legs require a sculpted musculature. As long as you’re doing an exercise mode that uses the lower body (like running, cycling, rowing, or squats versus arm cranking or swimming), intervals will build muscle in the glutes, thighs and calves.

For example, in one study, young men who did 20 minutes of bike intervals for 3 months increased leg musculature by 0.5 kg, while losing 2 kg of body fat. The reason sprints work is that they enhance protein synthesis pathways by as much as 230 percent and preferentially increases the size and strength of the powerful, fast-twitch fibers.

#3: Lean & Sustainable Body Composition

It’s been said that the true power of exercise for producing fat loss is in its ability to build muscle because this increases your total net calorie burn over the course of a day, everyday.

Besides weight training, interval workouts are the only way to achieve this. With endurance-style cardio you lose muscle over the long-term because it’s catabolic. Plus, it trains efficiency, which is the opposite of what needs to happen if you want to stay lean without progressively eating fewer calories as your metabolic rate goes down.

#4: Improve Your Body’s Ability to Burn Fat

Called “metabolic flexibility,” the ability to mobilize and burn body fat is extremely beneficial if you want to get and stay lean.

However, more and more people are not readily fat adapted, which is one reason they need to eat carbs throughout the day in order to avoid fatigue. If they were fat adapted, their body would be better able to shift into burning stored body fat.

There are two ways to do this: Changing your diet by reducing the carbohydrates you eat is one way, but this appears to only works for lean healthy people. For overweight people, exercise is the catalyst to become more metabolically flexible and intervals are the most effective method.

For example, in one recent study, doing four 30-second sprints on a cycle ergometer increased fat burning by 75 percent. The elevated use of fat for fuel was sustained for at least two hours after the workout.

#5: Fix A Bad Metabolism & Prevent Diabetes

Studies show intervals improve insulin health in the young, old, overweight, diabetic, and folks with metabolic syndrome.

By building muscle, you increase both the receptivity of the muscles to insulin and their demand for glucose. You also reduce inflammation and contribute to better body composition by improving fat burning and overall hormonal balance in the body.

#6: Lower Blood Pressure & Improve Heart Health

It’s a shame that endurance exercise got dubbed “cardio” somewhere along the way because it’s not the most effective way to improve heart health.

Comparison studies between interval and endurance training repeatedly show better cardiovascular outcomes from intervals. For example, a 2011 study in overweight women showed increased stroke volume and a reduced heart rate both at rest and during training after 4 weeks of cycle sprints.

Other studies show lower blood pressure, and better arterial structure, with a decrease in chronic inflammation that damages heart function.

#7: Less Risk of Tripping and Falling

Intervals improve power and coordination by priming the nervous system so that you react faster and have a quicker first step. They also build the fast-twitch muscles, which are the muscle fibers most associated with fall prevention in the elderly.

This is another reason that interval training is preferred over cardio-style exercise since it’s critical that we prioritize coordination and mobility as we age.

#8: Higher Testosterone & Growth Hormone

Interval training has repeatedly been shown to increase hormones that support body composition like testosterone (T) and growth hormone (GH). Men get a bigger T response than women but women increase GH more than men from intervals.

For example, trained men who did ten 30-second cycle sprints significantly increased T and related hormones. Another study of male wrestlers who did six 35-meter sprints with 10 seconds recovery showed increased T and decreased cortisol, leading to a favorable ratio between the two hormones.

In a comparison study, after three 30-second maximal intensity sprints, women had a much higher increase in growth hormone than men. Scientists think interval training should be a priority for women because GH increases fat burning and is likely involved in some form of tissue repair, although it’s unclear exactly how.

#9: Get Smarter

We’ve known for a while that exercise can protect the brain as you age, but more recent research shows that it actually improves learning.

In one study, participants improved their recall of new vocabulary by 20 percent after sprint interval workouts compared to a control group that did no exercise. Researchers think intense exercise makes you smarter because it raises the adrenaline hormones that stimulate the brain, while also boosting function of neurotransmitters like dopamine.

#10: Get More Powerful

Power is the ability to express strength quickly. Being strong is not enough. To truly reach your power potential, you need to also train the body to utilize the stretch-shortening cycle, which is the elastic component of the muscle.

Any kind of explosive interval training will do this, whether it’s all-out track sprints, stair running, or cycle ergometer intervals. Not only will maximal intensity intervals boost power, but you’ll find that lesser intensity workouts are so much easier.

#11: Better Endurance & Work Capacity

What most endurance trainees don’t know is that interval training is more effective than steady-state endurance training for improving speed, endurance capacity, and how long you can go before you quit.

This is because repeated intervals at a high intensity lead to the following adaptations:

  • They require the body to use energy more efficiently by increasing the amount of glycogen that can be stored in the muscle by as much as 20 percent.
  • Better use of fat for energy preserves muscle glycogen (what your muscles burn for energy during exercise), prolonging work capacity.
  • Intervals increase the body’s ability to remove waste products during exercise, leading to a 50 percent increase in what is called the muscle buffering capacity.
#12: Improve Mental Toughness & Motivation

Interval training is not a walk in the park. These workouts hurt. Some days are harder than others.

There will be moments of doubt when you are in the middle of a sprint workout. The pain and uncertainty in your ability to finish your workout is all in your head. You must not give in.

By pushing through the discomfort, you will build confidence in your physical and emotional ability. You will accomplish something not many other people can do.

To get started, check out this article that gives you interval protocols for different goals and conditioning levels.

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