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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  • Ethan Porter

    sexier as in being in better shape physically and being healthier overall

  • flab2fit

    Did it today. Though I am really out of shape, at the end 20 minutes my shirt was soaked and my face, red. 🙂 I did 45 seconds of jogging and 1 minute of walking x 10.

  • JayJay

    How about doing swimming laps. – is that good interval training?

  • Sam D.

    Is it ok to do this interval training on the same day as your weight training? I’ve heard from a variety of accredited sources that you should aim to get a sustained active heart rate (for me, 155 bpm) for 30 minutes, three times a week. I’m not sure what your take on that philosophy is, but because of my busy schedule, I need to make my workout times as comprehensive as possible.

    Currently, I’m planning on going on the Paleo diet, doing either the Beginner muscle-building workout you’ve suggested OR the other beginning weight training regimen I was referred to, which involves basic weight exercises using machines at my college’s workout center, and at least 15-20 minutes of this interval training or comparable cardio. So the workout would look something like this:

    1. 8 laps around 200 meter track for warmup
    2. Beginner weight training regimen
    3. 15 MAX minutes of cardio, I.E. treadmill, bike, stairstep with interval suggestions.

    Does this look ok? I’m at an acceptable body fat percentage right now (14-17%) but want to buff up and get that number a little closer to 11-12%. Any thoughts or suggestions?

    Thanks so much for providing this awesome site! You’re truly doing everyone who’s looking to get more fit a great service.

  • SlimCharles

    “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”
    I have never heard this. Do you have a source for this information? Not trying to be a jerk, just curious! Love your site, btw.

  • ehsan

    you can do this with a bike right

  • ehsan

    and what are some good stretches to do afterwards

  • Nicholas Terrill

    Hey Steve what would you recommend as an alternative for interval training? Because I have what they call Plantar Fasciitis on my right heel from being on my feet for eight hours everyday, so needless to say when I put too much impact on it, it stings like the dickens!

  • Jack

    After the exercise, can I suddenly sit. As I heard that when we do so, our butt will become big

  • Charlie

    I have a question, when steve says if your only able to do 3 or 4 intervals does he mean doing the full list above 3 to 4 times or just doing each step above? Also whats a good warm-up for interval training and good stretches to do afterward?

  • BRO

    I started doing HITT with jump rope, I started 30secs jump 30 secs rest for 10 minutes, and now I’m going to start 40-20, 10 minutes of jump rope burn more calories than 1hr in a treadmill.

  • AD

    I have been running for over a year, building up from a n00b into doing 2-3 miles per run a few times a week. I lost 40 lbs this way, then hit a major plateau. I have some more weight to lose – I enjoy running but am not really interested in expanding my runs to an hour. I’m about to start your bodyweight workout but also have started running intervals similar to what you describe here. In one year of running steady, I’ve never injured myself, but since I started doing intervals I inevitably hurt my knees during one of the sprints. Any ideas for how fast is too fast or how to avoid that? Thanks for your site!!

  • Bbx

    I have this mountainside forest road/trail close to where I live with lots of steep but fairly short (40-80m) up and downs along the trail. The trail itself is maybe 10km total..

    I would like to increase my stamina and oxygen capacity (not in very good shape) and was wondering if it would work as interval traning if I sprint up the uphills and then lightly jog the flats and downs..?

    How would this compare to what is explained on this page..?

  • Francisco Sala

    Would you really risk it and just interval as far as you can to avoid him? Hahaha.

  • Jen

    This may be further down in the comments thread, but what’s maximum effort? Do you mean the same thing as what’s calculated with target heart rate zones?

  • Extimes

    Max effort is, quite literally, giving it your all. If you could have gone faster, then do another interval. The build up in % of maximum sets the stage for this. You know you’re done when you can’t do any more intervals, or, tap out after a couple (10 intervals? 30 min? whenever you’re done with it). Next time, try harder or run faster, try adding another interval.

  • Extimes

    I love this kind of training, and kind of terrain! If you’re able to keep pace on the up hills, you’re probably hitting intervals. Guage for yourself whether you’re hitting the % max (of your individual effort) and step up the pace as necessary.

  • Extimes

    The interval is going from steady (warm up jog) to the increased rate. There’s 6 intervals listed above. The goal is to step up to your individual max. If you do a bunch of intervals and don’t hit it your first time out (or take forever doing it, or just get bored), stop and come back in 2 days with a little more speed, a little more intensity.

  • Extimes

    Try something like swimming, rowing, speed bag or other exercises that get your heart going without the impact to your feet.

  • Extimes

    Swimming is a great exercise. I know from my own experience that the difference between going at baseline and 100% is a lot of splashing and flailing and not much more speed. Make sure you’re focusing on your form and not sacrificing it trying to go faster/harder. An injury could set you back physically and mentally!

  • Extimes

    Yes! Any full body aerobic exercise works with HIIT.

  • Alisha Bale

    I don’t know how to differentiate percentages of maximum effort when I am working out. I have comfortable mode and uncomfortable mode. Advice? =/

  • Jane Sturges

    I guess my question is: I like to do weights (not circuit-style, strength-style). How do you balance that with HIIT? Do weights 3xweek and then HIIT twice or something? I’m worried about the recovery issues you mentioned, but I do want to get some form of cardio in, to get an overall balance.

  • Geo Fan

    IF (Intermittent Fasting) plus HIIT (Interval Training) is a miracle! Thanks for the info!

  • Geo Fan

    Diet + Exercies? IF (Intermittent Fasting) plus Interval Training (HIIT) works!

    My annual update

    Thanks for all the useful info, Steve, as always.

  • Geo Fan

    Diet + Exercise? Wow… IF (Intermittent Fasting) plus Interval Training (HIIT) works!

    My annual update

    Thanks for all the useful info, Steve, as always.

  • Dillip Mohanty

    I am a 5’11” guy. 68 kg.I can be considered skinny. I want to build up stamina and endurance. Should i do interval training??

  • Anthony Silva

    So could I do this on the off days of my body weight routine?

  • Elisabeth

    I want to do cardio, I actually love running but I have arthritis in both of my knees and I’m not sure what type of cardio I can do that won’t aggravate them. Any thoughts?

  • Nick PeterBurn

    After two weeks at this routine, cut your “decreased effort” time down from 2 minutes to 90 seconds….Do we also increase our “increased effort” time?

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  • Klassy

    That’s funny considering cross country runners are like the thinnest people I’ve ever seen lol.

    Circuit training is the best, and it’s pretty much all I do anymore, but if losing weight is your primary goal, go run a long and as far as you can as often as you can without hurting yourself. You will lose more weight than you think.

  • What if your warmup/cooldown is more like 10-15 minutes? My track is about 1.5 miles away, so I normally run there. Am I losing any of the metabolism benefits, particularly on the cooldown, if I’m running 1.5 miles to get home from the track AFTER my intervals?

  • rob

    Should that read the infamous tabata study?

  • Defected Salvations

    but if im bulking woul this be a no no?

  • Scott D. Kalter

    Steve, your article says “This will be your routine for three weeks”, but I didn’t see any reference to what comes next. What do you do after three weeks?

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  • Ryan

    I plan on doing the Beginner Bodyweight Circuit Mondays, Wednesdays, and Fridays. Would you suggest me doing the Interval Training Sundays, Tuesdays, Thursdays, and Sundays? Or do the Interval Training everyday after the Beginner Bodyweight Circuit?

  • Rosanna Hill

    Just starting .Up to now I have just been walking (4miles a day )and watching my calories .In 8 weeks I have lost 30lbs. But my scales have stalled so I feel I need to add something more to my “workout ” .Don’t know where to begin. Need to tone . Not much of a runner. Alternate interval and strength every other day ? Can’t wait to start with your program !!

  • RityS

    I’m going to give this a shot this afternoon 🙈 Should be great!!

  • Deep

    Is it for beginners , Steve ?

  • Deep

    Is it for beginners ??

  • Rodrigo

    one question, why is the program for 3 weeks?? If i have a bodyweight program, can i mix it with this?

  • sirpatrick

    I’ve done this on a treadmill 4 days a week for the last 18 months . I start out at a 3.5 mph( fast walk) for 3 minutes, go to 4.7 mph( slow jog) for 2 minutes, then back to 3.5 and then switch back every 2 minutes for 23 minutes total. I end going about 1.55 miles each session. I’ve lost 15 pounds and feel great. I wasn’t overweight to begin with but I have really toned and lost the fat around my midsection. 3 days a week I add 110 push-ups and 240 crunches after these sessions. I normally take Thursday, Saturday and Sundays off.

    My blood pressure is down to 112/70 and my resting pulse is always in the high 50’s and low 60’s. Not bad for a 63 year old man.

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  • Luvstosmile55

    I love to do hiiT on the upright bike. The best. I’m dripping in sweat after!
    Should I lift first, then hiiT? I definitely do all work outs fasted in the early AM

  • E

    Better shape physically so you can last longer and be healthier to make sure it never ends for the kids? Righto.

  • Mathieu Buchard

    So you said to only do this 3 times a week. Is it ok to do the “beginner body weight and excersises” on the other days?
    so 1 day interval training and the next day beginner body weight and keep doing that over and over.

  • David kdr

    Swimming was a costly venture, toss in travel time, pool membership and occasional road rage and you have fertile ground for change. The Max 5 Trainer is always waiting for me in my basement, there are no membership fees, it never smells like a diaper (pool), Just 15 minutes and prepare to receive endless benefits. It’s a deal I will never ignore.

  • Cc B

    I Just started myself about a week ago already see results.. my routine is 1 minute of very fast pace.. 7.5 on a treadmill followed by a brisk walk of about 4.0 for a minute then 6.5 down then 5.5 down to 4 and repeat for 30 min