High Intensity Interval Training (HIIT) is one of the top training trends in the fitness industry today. In addition to being a good challenge (the words “high intensity” in the title give that away), HIIT workouts can be quick and very effective.
While there are many ways to get in a HIIT workout (bodyweight intervals, Tabata, Boot Camp-style workouts, spin class, etc.), many may not think of using the treadmill for this type of workout. Most treadmill users do steady-state training by walking or jogging at the same speed setting or by using the same built-in workout that their treadmill offers. The body has an amazing way of adapting pretty quickly to the same type of workouts and that’s when you see the dreaded plateau set in.
The treadmill, however, can be a great tool when it comes to getting in the perfect HIIT workout.
Before we get into specific HIIT workouts utilizing the treadmill, let’s give a quick explanation of how HIIT works.
Why HIIT works: Fast-twitch muscle fibers and the “after-burn” effect
Because of the higher intensity, HIIT recruits fast-twitch muscle fibers. Fast twitch fibers are designed for anaerobic or short but powerful bursts of energy (think a track & field sprinter, a running back in football, etc.). Steady-state cardio, on the other hand, recruits slow-twitch muscle fibers, which are designed for aerobic or endurance-type activities (think long distance runners).
Fast-twitch fibers need more fuel than slow-twitch fibers … this allows them to not only function properly when called into play, but also to recover properly following a workout or sporting event. If your workout targets fast-twitch fibers, you’ll burn more calories during the workout AND after the workout. This later is known as the “after-burn effect” or excess post-exercise oxygen consumption, which allows your body to continue to burn calories well after your workout is over.
How to find the sweet spot for HIIT on a Treadmill
When using your treadmill for HIIT workouts, it may take a little experimenting on your part to find the right settings. Both the speed and incline settings can play important roles in designing a great HIIT workout. Try to find a setting that you can sustain for no more than one minute. For beginners or those new to HIIT training, this may be a 5mph jog with zero incline. For the more conditioned individual, it may be a 10mph run with a bit of an incline.
As you experiment, it’s important to learn what your one minute limit is. After this minute, you should feel pretty wiped-out and have a need to slow things down.
Next, after going all-out for a minute (this is your work interval), go “easy” for one to two minutes (this will be your recovery interval). Again, easy depends on your fitness level … it may be a 2.5 mph walk at zero incline or a 4-5 mph light jog. After the one-two minute recovery interval, you should feel ready to go all-out again.
A good gauge when first starting out is the Rate of Perceived Exertion Scale (RPE). An RPE of 1 means very easy, while an RPE of 9-10 means you’re out of breath and cannot speak. For the very fit individual, they should shoot for work intervals that get them up to that 9-10 level. For the HIIT beginner or less conditioned individual, they should shoot for an RPE of 6-7.
An all-out effort (one minute), followed by a recovery interval (one to two minutes), is one cycle. When first starting out, shoot for completing 6-8 cycles. Be sure to warm-up first for about 6-10 minutes and even include a couple of intervals below your max level to get your body acclimated.
Specific HIIT workouts you can do on the Treadmill
Here is a basic HIIT Treadmill workout that will help get you started:
1. Basic warm-up starting with a brisk walk and work your way up to a light jog – 10 minutes
2. Run at 10 mph for 30 seconds to 1 minute
3. Walk at 3.5-4 mph for 2 minutes
4. Repeat this cycle 7 more times (8 cycles total)
5. If the work interval isn’t enough of a challenge, add a slight incline to the treadmill
6. Perform a cool-down walk for 5 minutes before stretching and drinking plenty of water
As you build a love-hate relationship with HIIT training, experiment a bit with building your own treadmill HIIT workouts. Here are a few that have worked well for me and /or some of my training clients:
- 5-min warm-up at a brisk walk pace
- Run 1 minute at 7mph followed by 2 minutes at 5.5mph – repeat 5 times (15 minutes)
- Walk 1 minute at an easy pace to recover a bit
- Run 30 seconds at 10-12mph followed by 1 minute at 4mph – repeat 5 times (7.5 minutes)
- 4-minute cool down walk
- 0:00-5:00: Start walking or jogging at an RPE 5, gradually increasing the incline (without increasing your speed), so that by the end of the first five minutes, you’re at an RPE 6
- 5:00-7:00: Increase your speed while maintaining the incline, working at an RPE 7
- 7:00-9:00: Increase the incline and maintain your speed, working at an RPE 8
- 9:00-12:00: Reduce your speed, but maintain the incline, working at an RPE 7
- 12:00-15:00: Increase your speed and, if you can, increase the incline. These are your last three minutes of hard work, so push it! Try to work up to an RPE 9
- 15:00-20:00: Gradually reduce your speed and incline — by the last minute of your routine you should be back to an RPE 4 or 5
- 0:00-2:00: 6mph, Incline 1%
- 2:00-6:00: Alternate 30 seconds at 10mph and 3% incline with 30 seconds at 4mph and 3% incline
- 6:00-8:00: 6 mph, Incline 1%
- 8:00-12:00: Alternate 30 seconds at 10mph and 4% incline with 30 seconds at 4mph and 4% incline
- 12:00-14:00: 6 mph, Incline 1%
- 14:00-18:00: Alternate 30 seconds at 10mph and 3% incline with 30 seconds at 4mph and 3% incline
- 18:00-20:00: 6 mph, Incline 1%
- 20:00-22:00: 4 mph, Incline 1%
A few final notes on HIIT training
Push yourself. With HIIT training, you get out what you put in!
Be smart and safe with your treadmill…make sure you know how to operate the treadmill, know where the emergency shut off is, don’t hold onto the handles when running.
How often? Shoot for about 2 HIIT workouts a week in addition to your other favorite fitness activities.
Many treadmills come with interval-based training pre-programmed on the console. These can be helpful when your struggling to update your speed and incline during your workout. Look for treadmills with the science-backed Sprint 8 program.
About the writer: Ken Grall is a Certified Strength & Conditioning Specialist (CSCS) and owns and operates an Edge Fitness in Madison, Wisconsin. Learn more about Ken.