HIIT For Lazy Days

Some days I just feel lazy. I just feel like I have a lot to do and I will be more productive on my laptop instead of getting shoes on and do some running outside. A standard run for me is about 40 minutes. If you add the shower and all the additional logistics it easily adds up to 70-80 minutes. When I don’t feel like it I opt-in for a short indoor HIIT that takes just 25 minutes.

HIIT is High-Intensity Interval Training. The idea is that you cycle through a set of work and rest periods for a predefined number of times throughout the session by simply putting all-in effort for the work periods. Here is what I do in a 25 minutes long session.

What does “all-in” mean? It means around 85% to 95% of your maximum heart rate. In order to know your heart rate, you will definitely need a heart rate monitor, most probably a chest strap. According to Polar you can use a simple formula to calculate your maximum heart rate; 220 minus your age. In my case, it goes 220-37=183bpm (beats per minute). That means I need to stay between 155-177bpm during my work (all-in) periods. To be honest, my heart rate is already around 155-160bpm for a full 60 minutes run when I do outdoor running. I might need a real lab test to calculate my real HR-MAX. NTNU has a more sophisticated calculator on their site that gets me 189bpm HR-MAX. That results between 160 and 179bpm.

Above are the HR and indoor cycling cadence graphs of one of my HIIT sessions. You can see the spikes going between 160 and 170 bpm. My resting periods are between 140 and 155bpm. It does not matter if you increase your cadence as I did, or increase resistance; you just need to target the right heart rate zone.

The benefit of HIIT is not just the time you save. It is actually part of a good cardio program. It helps to increase the total amount of blood your heart can bump in a single stroke. The increase also means an increase in your VO2Max which measures how much blood your body can take to your muscles. From what I can tell VO2Max is considered an important indicator of cardio performance in the running community.

Considering I’m in a diet/weight loss mode right now, you might wonder if HIIT helps with weight loss. According to research, the 24-h energy expenditure of a HIIT session is similar to regular exercise despite reduced time commitment.

You don’t need to stick with my HIIT plan. You can design your own HIIT session. My preference is a one minute work - one-minute rest cycle. Yours might be a one minute work - three minutes rest. The importance is to hit the 85%-95% heart rate zone between periods and have decent rest. Finally, do never skip the warm-up and cool-down parts. Otherwise, you might be merely welcoming injury with the all-out effort mindset.

Finaly, here is a video from the Norwegian University of Science and Technology that pretty much summaries all I tried to write above :)

Make sure, you always consult your doctor before taking any of these plans into action.

See you next time.

#Fitness