Interval Training – Kick Your Ass and Kickstart your Metabolism in 20 Minutes

So you’ve heard amazing things about High Intensity Interval Training (HIIT).

You’re not quite sure what it is, only that people seem to like it and it helps them lose weight. You probably have questions like:

Is it running?


Why is it so popular?

What are the positives and negatives I need to consider?

If you’re a busy person, you don’t need to be spending hours a day on a treadmill or out jogging around your neighborhood to lose weight. In fact, those hours of running could actually be causing you a litany of healthy issues that I can help you avoid.

I’ll try to keep things concise so you can get to the root of the real reason why you’re here: “will Interval Training help me lose weight and get in shape?”

Let’s dig into what interval training is, and how you can use it to give your heart a great workout and kickstart your weight loss regiment.

What Is interval training?

Interval training is following a specific regiment where you vary your speeds and intensity throughout a shorter run/swim/bike/row.

Like the dog in the photo at the top or this tiger above, animals never run at the same steady pace; they walk and then SPRINT, or jog and then RUN. They don’t do this because they’re targeting a fat-burning heart rate, but just because they’re designed to operate in bursts like this.

You can learn from this too and use it to your advantage when it comes to your training.

Here’s a simple example: you might jog for three minutes, and then push yourself hard for a minute, repeating this cycle for a certain amount of time (usually around 20 total minutes).

Alternatively, you could sit on a rowing machine and row quickly for 30 seconds at an elevated rate followed by 30 seconds of rowing at a slower pace, and then repeat the process.

This style of training can carry over to cycling (if you’ve ever taken a Soulcycle, Flywheel, or similar class), running, rowing, swimming, rollerblading, and so on. Pretty much any form of cardio where you’re able to move at different speeds, High Intensity Interval Training is the art of varying your speed with purpose.

What are the Benefits of Interval Training?

Now, you’re probably wondering what makes an interval different from just jogging or running/moving at a constant pace.

Let’s dig into the nitty gritty:

You burn more calories while doing interval training compared to steady cardio: This type of training not only burns calories and builds up your oxygen capacity while exercising, but it can also produce an ‘afterburn’ effect that can leave your metabolism operating at a higher level of efficiency for hours and hours and hours after you’re done exercising. This means you’re burning calories while you’re sitting on your butt playing video games after your run.

Your heart is a muscle, Interval Training challenges it: if you keep your beating at a constant rate, never expanding it outside of its comfort zone, it will never grow stronger. This is the concept behind “antifragile” – by introducing chaos and pushing your muscles outside of their comfort zone, they must adapt and grow more resilient in order to survive!

If you constantly run or bike at the same steady pace every day, your heart adapts and learns to become more efficient (and thus needs to do less work) at that pace. However, when you throw some intervals in there, your heart will have to work harder, pump more blood, and work harder to return to normal levels. When your heart rate is constantly changing due to your varied training speeds, it’s becoming more resilient and will be better prepared to handle more chaos in the future.

Interval training improves both your aerobic and anaerobic capacity. As referenced in this post from

Mark’s Daily Apple: Dr. Tabata’s “famous study on moderate and high-intensity interval training helped legitimize a movement – away from chronic cardio and toward high-intensity workouts. This studies showed that high-intensity intermittent training actually improves both anaerobic (intensity and muscle building) and aerobic (slower, oxygen consuming) body systems, while aerobic exercise only improves aerobic systems.”  Two for one!

note: Tabata training is highly advanced – you’ll still see similar results with interval training compared to Tabata training as it operates on the same principle.

A quick Note about Interval Training and Weight Loss

My guess is that you’re reading this article because you’re trying to get the most efficient “bang for your buck” when it comes to getting in shape.

As we point out in our article “what’s better: interval training, cardio, or weights,” if you only have 20-25 minutes to train, doing intervals is more efficient than steady cardio.

But the reason you’re doing that is most likely to lose weight, right?

So let’s talk about that for a second. For starters: how you eat will be responsible for 80% of your success or failure.

One of the Rules of the NF Rebellion is that “you can’t outrun your fork.”

This means that I don’t care how many intervals you do, it’s not gonna help you lose weight if you don’t also fix your nutrition. You can read our beginner’s guide to nutrition if you want more information.

Next! intervals CAN be part of your weight loss strategy, just like cardio can be, as long as you are also taking care of yourself in other ways too!

If you want to download our free 10-level Nutrition Guide to help you fix your diet starting today, you can do so by signing up in the box below:

How to interval train

Let’s take you through a sample running guide for interval training.

Three  days a week of running is sufficient – if it’s done right, your body will need 48 hours to recover between exercises, and actually burn fat on your off days, when you’re sitting at your computer or playing videogames.

This will be your routine for three weeks:

  • 5 minutes of warmup...light walking, bump the speed up a little bit to get your legs warmed up…then stretch.  Don’t stretch until you’ve warmed up.  Think of your muscles like rubber bands…you quickly pull a rubber band that hasn’t been used yet and it’ll snap.  Warm it up, get it used to activity, then stretch it, and you’re golden.
  • 30 seconds of increased pace (70% of maximum effort)… 2 minutes of decreased pace.
  • 30 seconds of increased pace (75% of maximum effort)… 2 minutes of decreased pace.
  • 30 seconds of increased pace (80% of maximum effort)… 2 minutes of decreased pace.
  • 30 seconds of increased pace (85% of maximum effort)… 2 minutes of decreased pace.
  • 30 seconds of increased pace (90% of maximum effort)… 2 minutes of decreased pace.
  • 30 seconds of increased pace (100% of maximum effort)..2 minutes of decreased pace.
  • 5 minutes of light jogging and stretching. When you stretch afterwards, your muscles expand, allowing the nutrients you’re about to eat to fill in the gaps that are now empty from exercise.  Also, it keeps your muscles loose, so there’s a far less chance for injury.

Now, because this is your first time doing intervals…it might be tough to get through the routine. If it is, concentrate on doing the intervals as strongly as possible (really push yourself on those 30 seconds fast sections)…and if you can only get through 3 or 4 intervals, stop there.  The next time, aim for 5 intervals, then 6, then 7.

The reason I don’t tell you how fast to run for either, is because it’s different for each person.  If you’re really out of shape, your 90 seconds might be walking, and your 30 seconds might be jogging.  If you are in shape, your 90 seconds might be jogging and your 30 seconds might be sprinting.

You should be close to death by the time you complete this cycle…okay maybe not that bad, but you should be dripping in sweat.   If you’re not, then you were faking it, and you’re only screwing with yourself.

What if I don’t LIke RUnning? Help!

“Steve, this all sounds great. But I hate running!”

Confession: So do I. So I don’t run, ever.

I used to run cross country in high school, and I’ve tried to get excited about running about a dozen times since then.  After reading Born to Run, a fantastic book, about running, I even had myself convinced that I was going to LOVE running.  Every time I get started, about ten minutes into my run, I just get bored as hell!

We don’t believe in doing exercise you hate, so we’ll never tell you to go to the gym if you hate gyms or get on a bike if you’re afraid of biking without training wheels.

Instead, I train in a way that makes me happy – when you think about it, powerlifting is like concentrated forms of interval training: periods of rest followed by intense moments of maximum effort!

So, if you aren’t interested in running but like the idea of Interval Training, consider trying it with other activities:

  • Hiking, swimming, climbing, cycling, rowing, jumping rope.
  • Basketball, tennis, soccer, and frisbee are AMAZING styles of exercise that use interval training (it’s all start and stop!)
  • Gymnastics, powerlifting, parkour

In ever exercise above, you’re varying your tempo, speed, effort, and endurance. And it can help make your heart better, burn more calories, and get you rocking and rolling!

What else Do I need to KNow?

I bet you have one final question: “how do I incorporate interval training into my life!?”

Are you supposed to run on alternate days? What if you also want to do yoga or weight training? What’s the best strategy for losing the most weight in the least amount of time?

I hear ya – this stuff can be super overwhelming and challenging.

We offer a TON of free resources that can help you make sense of your fitness journey, cut through the crap, and get you results.

For starters, we have our self-paced online course, the Nerd Fitness Academy, which has helped 40,000+ students level up their lives. Workout plans, 10-levels of nutritional strategies, boss battles, a leveling up system, mindset missions, and a supportive community!

We also have TONS of free resources that I’ll send you when you sign up in the box below, where you can join hundreds of thousands of people that I email regularly with new health and fitness content (and sometimes animal photos):

Thanks for reading, let us know if you have any more questions below!



photo, Tigress running in the water, Five Furlongs Snow Fun With Lena, go Boris go

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