What is HIIT?
HIIT stands for High Intensity Interval Training. In HIIT workouts, you do very intense exercises for short bursts of time before taking a planned, short rest.
During this rest, you either workout lightly or completely rest. You then alternate between intense intervals and rest intervals throughout the workout.
This type of exercise is designed to burn fat and build muscle in an incredibly short amount of time. HIIT sessions are also very flexible.
You can do them on the treadmill, elliptical, stair machine, or bicycle. You can also do these without any equipment – you just need your body weight.
A HIIT workout is generally defined as exercise in the heart rate range of 80-95% of max heart rate. Click to learn more about heart rate training zones.
The 20 Minute Treadmill HIIT Workout
Doing a HIIT workout on a treadmill is a great way to get cardio in and burn lots of fat. Here’s a great one to get you started. You can do this one anytime you have a few minutes to burn some calories. And remember that you can adjust the speeds based on your ability and heart rate, as well as your experience level.
1) Warm-up. Set the treadmill speed to 3.0. Walk for 1-2 minutes at this slow, moderate speed to get your muscles warmed up.
2) Then, run at a fast jog, around 7.0 to 9.0 mph, for 30 seconds. This is your first high intensity interval! You will want to “ramp up” the speed on the treadmill ~ 10 seconds prior to the “fast jog” cycle as it will take a little time to get up to speed.
3) Next, drop the treadmill speed to 3.0 again and walk slowly for 60 seconds.
4) Alternate between these intervals for 20 minutes.
5) End by cooling down at a speed of 3.0 with a 2 minute walk.
The Details of the 20 Minute Treadmill HIIT Workout
This shows the details of the 20 minute treadmill HIIT workout. You will see that you start to increase treadmill speed 10 seconds prior to your HIIT burst, as it will take that long for the treadmill to speed up to 7.5 or 8.0 mph.
Treadmill Timer | Exercise | Duration | Treadmill Speed
| Treadmill Timer | Exercise | Duration | Speed |
|---|---|---|---|
| 0:00 – 1:00 | Walking | 1 minute | 3.0 |
| 1:00 – 1:30 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 1:30 – 2:30 | Walking | 1 minute | 3.0 |
| 2:30 – 3:00 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 3:00 – 4:00 | Walking | 1 minute | 3.0 |
| 4:00 – 4:30 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 4:30 – 5:30 | Walking | 1 minute | 3.0 |
| 5:30 – 6:00 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 6:00 – 7:00 | Walking | 1 minute | 3.0 |
| 7:00 – 7:30 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 7:30 – 8:30 | Walking | 1 minute | 3.0 |
| 8:30 – 9:00 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 9:00 – 10:00 | Walking | 1 minute | 3.0 |
| 10:00 – 10:30 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 10:30 – 11:30 | Walking | 1 minute | 3.0 |
| 11:30 – 12:00 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 12:00 – 13:00 | Walking | 1 minute | 3.0 |
| 13:00 – 13:30 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 13:30 – 14:30 | Walking | 1 minute | 3.0 |
| 14:30 – 15:00 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 15:00 – 16:00 | Walking | 1 minute | 3.0 |
| 16:30 – 17:00 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 17:00 – 18:00 | Walking | 1 minute | 3.0 |
| 18:00 – 18:30 | Fast Jog | 30 seconds | 6.5 – 9.0 |
| 18:30 – 20:00 | Walking | 90 seconds | 3.0 |
Pro Tips for HIIT
Proper Hydration Prior to HIIT
HIIT is exactly what the acronym says – high intensity. This puts a load on your muscles that they don’t get on an everyday basis. So it’s very important to be properly hydrated when doing HIIT, or your muscles will cramp (especially legs). And this doesn’t mean drinking a 1/2 gallon of water an hour before the workout. It means for the day prior. But proper hydration is important for many reasons, so practice hydration daily and you’ll be fine during your HIIT workout.
Excellent Health Prior to HIIT
HIIT is best performed by people who have a base fitness level. It is not suited for a beginner who might be 50 pounds overweight, and has not worked out in 3 years. It is always best to consult your doctor prior to doing any high intensity exercise, including HIIT. Learn more about the risks of HIIT here. (1)
Make Sure Your Muscles are Warm and Loose
HIIT puts an extra burden on your muscles and your body, which is why it is so effective. This also brings certain risk to the process. So make sure your muscles are properly warmed up and loose prior to your HIIT workout.
An effective warm-up is walking at a slow speed (3.0) on treadmill for 1-2 minutes prior to starting HIIT.
Safety on a Treadmill
A treadmill can be a dangerous place for HIIT unless you are very focused on the task at hand! Make sure you stay very focused when doing HIIT on a treadmill, and the dangerous part is obviously the sprinting (or fast run) phase of HIIT. So follow these safety tips:
- Make sure that your running shoes are laced tightly so they will not unlace. Check them during the walk phase of HIIT.
- Ensure that you stay in the exact center of the treadmill. It’s easy to lose focus and drift to one side, or drift to the back of the treadmill. If your foot steps off the treadmill in any direction, you will crash hard.
- Don’t get distracted by the treadmill TV, or your music. You don’t want to “zone out” and lose your focus. Stay very focused on your sprint and staying in the center of the treadmill.
- Practice in your mind to prepare for an instant cramping muscle (hamstrings, or back of thigh, are most common). And how you will immediately step off to the left and right rails so that you straddle the treadmill, and at the same time grab the handrails with your hands. Be mentally prepared for this possibility, so if you were to have a cramping leg muscle, you are ready. A cramping leg muscle can lead to a wipeout if you’re not prepared.
- Emphasizing the point above: make sure that you are well hydrated prior to HIIT, as the intensity can create cramping if your muscles are dehydrated.
What are the Benefits of a HIIT Treadmill Workout?
HIIT workouts are generally quite short compared to regular cardio, so you can squeeze them into your busy schedule with little problem. Most HIIT workouts typically last 4 to 20 minutes, so they are quite short. HIIT is also very effective! You can burn a lot of fat and build muscle without spending hours at the gym. The 20 minute treadmill HIIT workout is perfect for the busy working person.
HIIT workouts are great for more than just losing weight. They increase the number of calories you burn for up to 72 hours after each workout. They also activate your fast-twitch muscles (type II), which you use when jumping or sprinting. HIIT can also increase your metabolism and endurance. (2)
Who is a HIIT Treadmill Workout for?
HIIT treadmill workouts can be done by just about anyone, but you should always be cautious with high intensity workouts! See pro tips below. But if you’re in good health, and you can run and walk on a treadmill, then you can do this workout.
However, if you have any type of medical conditions that could be worsened by a rapid increase in your heart rate, then HIIT will probably not work for you. Remember, the main goal is to get your heart pumping by doing short bursts of activity!
HIIT workouts should also be approached with caution if you have any type of injury. You should still be able to get a workout in, but be sure that you aren’t pushing yourself too hard! You don’t want to sustain the same injury again and slow down your recovery.
This 20 minute treadmill HIIT routine is a great way to ensure that you get an awesome workout when you don’t have much time. If you’re new to HIIT, just go for 10 minutes at the beginning, and at slower speeds. It takes some practice to get comfortable with HIIT. As you gain endurance, you can increase the time until you can go for the full 20 minutes!
Return to more HIIT Workouts.
David Williams
A diet and fitness enthusiast, David Williams is an ex-Army Airborne Ranger and Infantry soldier with decades of fitness and wellness experience. A West Point graduate with a degree in engineering, he focuses on technical research related to fitness, nutrition, and wellness. He loves the beach, and spending time with his wife and daughters.
References
- Clark, S. (2015). High-Intensity Interval Training Is An Effective Fitness Trend, But It’s Not For Everyone. Medical Daily. https://www.medicaldaily.com/high-intensity-interval-training-effective-fitness-trend-its-not-everyone-336448.
- Penney, S. (n.d.). Fast-Twitch Vs. Slow-Twitch Muscle Fiber Types + Training Tips. NASM. https://blog.nasm.org/fitness/fast-twitch-vs-slow-twitch.
