4 Cardio Workouts That Maximize Your 'Afterburn'

woman running on treadmill
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One of the great things about exercise is that, not only do you get the benefits during your workouts, the rewards keep on coming...that is, if you're doing the right kind of exercise.

That reward is what we call the "afterburn," also known as post-exercise oxygen consumption (EPOC). The afterburn refers to the amount of oxygen your body consumes above resting level after your workout. Or put another way, it's how many calories your body burns before it gets back to its pre-exercise state.

Exercise triggers all kinds of responses in the body, starting with your metabolism. Your metabolism goes up and, if you work at a high intensity, it stays up for a period of time after.

There are a number of physiological mechanisms responsible for this, chemical reactions that replace oxygen stores, replenish energy stores and more. Luckily, we don't have to understand how it works to take advantage of it.

The bottom line? The more afterburn you can generate, the more calories you burn and the more weight you lose.

What's So Important About EPOC?

It's obvious that burning more calories both during and after a workout is good for us, but afterburn has come to mean a lot more in recent years. Experts believe that afterburn may be the key to fighting obesity.

What they've figured out through a variety of studies is that the afterburn generates about 10 percent of your total energy expenditure of exercise, which is nothing to sneeze at.

Not only that, but an afterburn of 80-100 calories per workout could add up to 3 to 6 pounds of fat loss per year. In a way, that's like losing more weight without having to work for it.

Getting More Afterburn

The real question is, how do you generate that afterburn? When it comes to cardio, there are several factors that determine your afterburn:

Looking into various studies about the afterburn, experts found that the greatest afterburn occurs:

  • When you work at about 75% of VO2 Max. VO2 Max refers to the maximum amount of oxygen a person can use during intense exercise. This is usually measured in a laboratory setting. For those of us who don't have a lab handy, we can use equivalents to estimate VO2 Max. 75% is equivalent to about a Level 8 on this Perceived Exertion Scale (RPE). This would be activities like racewalking, running at a fast pace, or jumping rope. You can even use a calculator to estimate your VO2 Max based on your heart rate.
  • When you do short bouts of exercise. For example, two 20-minute workouts done at a high intensity or incorporating interval training elicits more afterburn than one continuous workout.
  • When you're a beginner. Newbies generate more afterburn because the movements are new to the body, which means expending more calories. As you become more experienced, your body becomes more efficient and, thus, burns fewer calories overall.

    The Best Workouts for Afterburn

    With all of these factors in mind, below are four different 25-minute workouts that will get you into that heart rate zone where you'll burn more calories both during and after your workout.

    They all include some form of high intensity interval training (HIIT), which is a more advanced form of exercise. If you've never done HIIT, start with a more moderate Interval Training Workout and slowly work your way to higher levels of intensity.

    Keep in mind that HIIT workouts are very taxing on the body, so only do them 1 or 2 times per week and make sure you give yourself recovery days after, either by doing lighter workouts, lifting weights, or nothing at all.

    Workout 1: Rolling Interval Treadmill Workout

    This is the perfect workout for generating afterburn. The idea is to start at a moderate intensity and increase the intensity to hard and then very hard by using speed or incline, repeating that through three different intervals.

    Keep track of your Perceived Exertion and change the settings for each segment as needed to match the RPE. In other words, you don't have to (or may not be able to) stay at the same speed or incline for the entire workout. 

    TimeIntensity/SpeedRPE
    6 MinWarm Up, gradually increasing speed and/or incline to reach moderate intensity. This is baselineWorking up to a Level 5
    5 MinStart at Baseline and increase incline 1-2 increments each minuteWorking up to Level 8
    Rolling Interval 1 - Incline
    1 MinModerate: Increase your incline to 6%, choose a pace that allows you to work at a moderate intensityLevel 5
    1 MinHigh: Increase incline to 8%,Level 6-7
    1 MinVery High: Increase incline to 10%, adjust your speed to maintain a very high intensityLevel 7-9
    Rolling Interval 2 - Speed
    1 MinModerate: Bring your incline to 1% and set your speed to moderateLevel 5
    1 MinHigh: Increase speed to work at a hard intensity, incline remains at 1%Level 7
    1 MinVery High: Increase speed to work at an even harder intensity, incline 1%Level 9
    Rolling Interval 3 - Incline
    1 MinModerate: Baseline:  Incline at 6.5%, speed at a moderate intensityLevel 5
    1 MinHigh: Increase incline to 8.5%, same speed or lower if necessaryLevel 7
    1 MinVery High: Increase incline to 10.5%, same speed or lowerLevel 9
    5 MinCool down at an easy paceLevel 4
    Workout Time: 25 Minutes

    Workout 2: Tabata Training

    Tabata training is a form of HIIT that really gets your heart pumping, resulting in an amazing afterburn. The idea is to work as hard as you can for 20 seconds and then rest for only 10 seconds. You repeat that 8 times for a total of 4 minutes.

    This workout includes 4 blocks in which you'll alternate two exercises for each Tabata. You don't need any equipment, although using a timer, like this Tabata Pro App, will make the workout easier to follow. 

    Warm Up Tabata - 4 Minutes

    • Puddlejumpers - Step out to the right with a wide step while reaching the arms out. Now take a wide step to the left, getting as low to the ground as you can while taking the widest step you can.
    • Straight Leg Kicks - Lift the right leg, keeping a slight bend in the knee, to hip level or higher. At the same time, circle the right arm around and down, as though you're trying to touch the right toe (you probably won't...that's okay). Lower and repeat on the other side, going as fast as you can.

    Alternate each exercise, doing each for 20 seconds and resting for 10 seconds between exercises. Repeat the series 4 times for a total of 4 minutes. Take a short rest and go to the next Tabata.

    Tabata 1 - Burpees and Mountain Climbers - 4 Minutes

    • Burpees - Place your hands on the floor, jump the feet back into a plank, jump the feet back in and stand up. Add a jump for more intensity, or walk the feet back instead of jumping if you need a modification.
    • Mountain Climbers - While on the floor in a plank position, run the knees in an out as fast as you can.

    Alternate each exercise, doing each for 20 seconds and resting for 10 seconds between exercises. Repeat the series 4 times for a total of 4 minutes. Take a 60-second rest and move on.

    Tabata 2 - High Knee Jogs and Plyo-Jacks - 4 Minutes

    • High Knee Jogs - While jogging in place, bring the knees up to hip level, circling the arms overhead to add intensity.
    • Plyo-Jacks - Jump the feet out and bend the knees into a squat, going as deep as you can. Jump the feet back together into a squat while circling your arms. This move is slow and controlled.

    Alternate each exercise, doing each for 20 seconds and resting for 10 seconds between exercises. Repeat the series 4 times for a total of 4 minutes. Take a 60-second rest and move on.

    Tabata 3 - Jumping Jacks and Plyo-Lunges - 4 Minutes

    • Jumping Jacks - Jump the feet out wide while circling the arms up overhead. Jump the feet together as you lower the arms. Go as quickly as you can.
    • Plyo-Lunges - Start with feet together and jump up, landing in a staggered stance with right leg forward left leg back, bending the knees in a lunge. Jump up, switch feet in the air and land with the other leg forward.

    Alternate each exercise, doing each for 20 seconds and resting for 10 seconds between exercises. Repeat the series 4 times for a total of 4 minutes. Take a 60-second rest and move on.

    Tabata 4 - Ski Hops and Speed Skaters

    • Ski Hops - Keeping feet together, bend the knees and jump to the right as far as you can. Jump to the left and continue going from side to side as fast as you can.
    • Speed Skaters - Jump to the right, landing on the right foot. Immediately take another lateral jump to the left, jumping as far as you can and keeping low to the ground rather than jumping up in the air.

    Cool down: Take 5 minutes to cool down, allowing your heart rate to slow down. End your workout with a well-deserved stretch.

    Total Workout Time - 25 Minutes

    Workout 3: Mixed Interval Workout - Threshold and Aerobic Intervals

    This mixed interval includes high intensity intervals, alternating speed and hill or resistance work as well as longer aerobic intervals.  The differences between the aerobic intervals are subtle, so pay attention to your intensity and make adjustments throughout the intervals to stay within the suggested perceived exertion. You can do this workout on any cardio machine or even outside, if you're walking, running, or cycling.

    TimeIntensity/SpeedRPE
    5 minWarm up at an easy-moderate pace4-5
    1 minBaseline: Increase speed gradually to slightly harder than comfortable5
    1 minIncrease speed/resistance to work harder than baseline6
    1 minIncrease speed/resistance to work harder than previous interval7
    1 minIncrease speed/resistance one more time to work as hard as you can8
    2 minBaseline5
    High Intensity Interval Block 
    90 secHill - Keep your pace the same and increase incline/resistance to that you're working hard7-8
    60 secRecover at a comfortable pace4-5
    90 secSpeed - Increase pace so that you're working hard7-8
    60 secRecover4-5
    90 secHill - Increase incline/resistance to that you're working hard7-8
    60 secRecover4-5
    90 secSpeed - Increase pace so that you're working hard7-8
    Cool Down
    4 minCool down at an easy pace and stretch3-4
    Total: 25 Minutes

    Workout 4: Outdoor Circuit Workout

    Outdoor workouts are nice, but they can get a little boring. One way to spice them up while creating more afterburn is to sprinkle some high intensity moves throughout your walk or run. You'll do sprints and/or hill climbs, depending on your terrain, and some plyometric moves that will work every muscle in your body and send your heart rate soaring.

    TimeActivityRPE
    5 minWarm-up - Brisk walking or a light jog 4
    2 minBaseline: Walk or jog
    This is your baseline pace. You should feel slightly breathless.
    5
    20 repsJumping Lunges
    In a split stance, jump up and switch the feet in the air, landing with the opposite foot forward. Repeat for 20 reps.
    6-7
    1 minSpeed walk, Sprint or Hill Climb
    Pick up the pace or, if you're at a hill, climb it as fast as you can.
    7-8
    1 minWalk or jog 
    Slow down enough to lower your heart rate back to baseline.
    5
    20 repsJumping Lunges
    In a split stance, jump up and switch the feet in the air, landing with the opposite foot forward. Repeat for 20 reps.
    6-7
    1 minSpeed walk, Sprint or Hill Climb
    Again, sprint or climb a hill as fast as you can.
    7-8
    1 minWalk or jog 
    Slow down to get back to baseline.
    5
    1 minSprints
    Choose an object in the distance (a tree, mailbox, etc.) and run/walk to it as fast as you can. Walk for 10 seconds and repeat the sprints for the full minute.
    8
    2 minWalk or Jog
    Slow down to baseline.
    5
    20 repsPlyo-Jacks
    Jump in the air and land in low squat. Jump the feet back into a squat, going as deep as you can. Repeat for 20 reps.
    6-7
    1 minSpeed walk, Sprint or Hill Climb
    Spring or hill-climb as fast as you can.
    8
    20 repsPlyo-Jacks
    Jump in the air and land in low squat. Jump the feet back into a squat, going as deep as you can. Repeat for 20 reps.
    6-7
    1 minSpeed walk, Sprint or Hill Climb
    For your last sprint/hill, see if you can go faster than before.
    8
    2 minWalk or Jog
    Slow down to baseline.
    5
    3 minCool down with an easy walk.3-4
    Total Workout Time: 25 Minutes

     

    Try one or two of these workouts per week to generate more afterburn, using the other days for more moderate cardio, weight training, and stretching. Not only will you burn more calories, you'll bump up your endurance, making all your other workouts feel easier than ever. Not a bad bonus.

    Sources:

    Dalleck L, Van De Velde S. "Could EPOC Help Solve the Obesity Epidemic?" ACE Fitness. https://www.acefitness.org/prosourcearticle/6091/could-epoc-help-solve-the-obesity-epidemic. 

    Laforgia J, Withers RT, Gore CJ. "Effects of exercise intensity and duration on the excess post-exercise oxygen consumption." Journal of Sports Sciences. 2006;24(12):1247-1264. doi:10.1080/02640410600552064.

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