Examining High-Intensity Exercise
A few weeks back we came across a great article in the New York Times titled “Too Much High-Intensity Exercise May Be Bad for Your Health - A new study hints that excessive HIIT may harm your mitochondria, the energy generators found in every cell of your body.”
It sparked a great discussion amongst our training staff and we thought we’d share some of our thoughts:
Michelle Young
This is an interesting article! The concept of which I think about quite often, as cardio, particularly HIIT, is one of my favorite forms of exercise.
A HIIT workout, if designed and coached appropriately, should tax the body to the point of only being able to complete roughly twice a week. The anaerobic system should be in use for most of the workout, making it only 15-20 minutes long. (For the sake of this article, let's use the example of the HIIT workout they do in this article. I think “HIIT” has now taken on different formats.)
I agree with this article. HIIT is not the end all be all of the fitness; It's simply a tool. It should be paired alongside strength training, mobility, active recovery, and many other modalities.
In my opinion, if you're able to coach or perform a classic HIIT workout more than three times a week or for periods of time longer than 20 minutes, you're not doing correctly.
Concurrently, this is a singular study and being smart about programming, tweaking to each individual’s needs is most important for me.
What are your thoughts?
Max Davis
Interesting read!
I really agree with Michelle about HIIT being a tool and that true HIIT cannot be performed frequently.
This is how I see HIIT vs LISS- The main tradeoff I see is that HIIT has a great stimulus to time ratio but a poor stimulus to fatigue ratio. It's efficient in terms of time but inefficient in terms of fatigue management. The opposite would be true for LISS. In application, I would choose LISS vs HIIT based on the client's goals and priorities. If they want to optimize strength as well as muscle gain/retention I would get them to perform LISS. LISS would ideally have a lower recovery cost which would allow more room for resistance training volume and/or intensity. That being said, optimization isn't in the cards for most people. If a client has limited time to train each week (which is mostly the case with our clients) HIIT is a great option because of time efficiency.
Here is a good article about the interference effect. I think that LISS is great for those who want to do cardio but also want to minimize the interference effect.
A big part of the article that stood out to me is where they mentioned that the effects of the HIIT training were minimized because of the participant's sedentary lifestyles. They had a great piece on the latest edition of MASS Research Review about sedentary people who perform intense physical activity a few times per week. Here was one of the studies they talked about: https://pubmed.ncbi.nlm.nih.gov/30763169/
I would recommend checking out the entire MASS article. This makes me think even more about how important step tracking is.
What are your thoughts? Feel free to comment below!