HIIT workouts have become all the rage these days. If you open any fitness magazine, they will praise this type of workout, since it’s an effective way to burn a lot of calories in a relatively short amount of time.
In this article, I’ll give you an overview of what this type of workout actually is, how it can impact blood sugars, and how to manage the impact. And we’ll look at three workouts you can do either on a spin bike, without equipment or with a gym membership.
What is a HIIT workout?
HIIT is an abbreviation for High-Intensity Interval Training. It’s a type of workout during which you switch between pushing yourself as hard as you can (usually for up to 30 seconds) and periods of low intensity or total rest (usually for about 2 minutes).
By switching back and forth between intensity and rest, your heart rate is elevated to your maximum range for short periods, and then it comes down to a lower range.
Given that the intensity of a HIIT workout is often no longer than 20 minutes, this enables you to push yourself much harder than you would during a longer workout. Quality over quantity! It’s all about the intensity rather than the duration when it comes to HIIT.
Some research has shown that doing this type of shorter high-intensity workout is as effective as a longer workout, like jogging or swimming during which you maintain the same steady and lower-intensity pace.
However, HIIT training is also taxing for the body. It’s recommended that you do no more than two to three HIIT sessions per week. I generally recommend a mix of resistance training, steady state cardio, and HIIT workouts for the average healthy adult.
How does HIIT impact blood sugars and how do you manage it?
If you’re used to doing cardio, you most likely are used to your blood sugars decreasing significantly when you work out. HIIT training is different because it’s a type of training called anaerobic training.
Anaerobic training can often increase your blood sugar during your workout, followed by a potential sharp decrease after. (More on why some types of training can increase blood sugars HERE.)
That doesn’t mean that anyone living with diabetes shouldn’t do HIIT, or that you have to accept high blood sugars during your workout. Instead, it simply means that you have to implement a different blood sugar management strategy than you would if you did steady state cardio. Again, steady-state cardio is performed at a lower and more consistent intensity, which creates a more consistent heart rate, too.
Finding Your Formula for Diabetes and Exercise
Figuring out how to manage your blood sugar during a HIIT workout is actually no different than any other type of exercise.
I call it Finding Your Formula for Diabetes and Exercise. Finding your formula for HIIT workouts comes down to using an “Exercise Log” for taking detailed notes on how your body reacts to HIIT. Then you’ll review your notes and adjust your diabetes medication and carbohydrate intake to match your body’s reaction for the goal of balanced blood sugars during exercise. (You can find more details on my methodology and download my Exercise Log HERE.)
What I’ve found, through my own diabetes management and through coaching others with diabetes is that most will see their blood sugar shoot up pretty quickly when they start a HIIT workout. However, variables like the time of day and when your last meal was consumed can have a huge impact on the results.
This means that the more consistent you are in managing these variables, the more consistent your diabetes formula and blood sugar levels will be, too.
- If you perform your HIIT workout first thing in the morning — before eating anything — you’ll likely see a significant rise in your blood sugar because you’re in a fasted state. (Read more about fasting and diabetes HERE.)
- If you don’t eat a meal shortly after your HIIT workout, you’ll likely see your blood sugar continue to linger in a higher range because you haven’t bolused any fast-acting insulin for a meal.
- If a small meal is eaten with a reduced amount of insulin or a small dose of insulin without any food, the blood sugar spike from anaerobic HIIT workouts tends to be less aggressive and more manageable.
One thing to note is that if you do use insulin to manage your blood sugar and decide to take a correction after your HIIT workout, please do so with caution since your insulin sensitivity will be fired up and you might only need as little as 50 to 25 percent of your usual correction dose to get back into your goal range.
Remember, we’re all different, so after tracking your blood sugars and working on your formula you might find that you don’t spike as much or that fasting HIIT really works well for you. And that’s great! In the end, it’s about doing what’s right for you and your body.
HIIT workouts that will make your blood pump 😊
Now that you know what HIIT is, and how you can find your formula for managing your blood sugars, let me give you a few practical workout examples that you can try out yourself.
- 25-min HIIT Bike Workout: Ideally, you’d do this on a spin bike where you can easily change the resistance.
- 5-minute steady state warm-up (get your heart-rate up)
- 20-minute intervals: 8 rounds of 30 seconds all out (dial up the resistance nob two turns or more) followed by 2 minutes steady-state (dial back down two turns)
- 25-min HIIT Bodyweight Workout: You won’t need any equipment!
- 5-minute warm-up: Jumping jacks, skipping, jogging, dancing
- 20-minute intervals: 8 rounds of 30 seconds all out (select one exercise or alternate between burpees, jump with knee tucks, squat jumps, sprints, or another favorite exercise that makes your heart pump) followed by 2 minutes steady-state (jumping jacks, skipping, jogging, dancing, marching in place)
- 25-min HIIT Gym Workout: You’ll need some equipment!
- 5-minute warm up: Jogging, rower, stationary bike, jump rope
- 20-minute intervals: 8 rounds of 30 seconds all out (move through the exercises below) followed by 2 minutes steady-state (Jogging, rower, stationary bike, jump rope)
- Medicine ball slams
- Medicine ball squat toss
- Battle ropes
- Jump with knee tucks
- Renegade rows with push-up
- Dumbbell squat to press
- Frog jumps (with or without dumbbells)
I hope you have fun with these workouts. And remember, safety first! Always do a warm-up, measure your blood sugar, and always carry emergency snacks to treat and prevent low blood sugars.
Christel Oerum has been living with type 1 diabetes since 1997. She is the main content creator on Diabetes Strong, and is an active diabetes advocate, public speaker, and diabetes coach.