Take It More Slow to Live Longer?
What is zone 2 training and why is it important for longevity.
Hey,
What if I told you that taking it more slow when exercising may make you live longer? Yup, that’s right. I’m talking about zone 2 training. I’ve been taking this type of training more seriously the last few months and I recommend it to everybody.
Here’s a very short explanation:
What?
Zone 2 (Z2) is a specific, aerobic exercise intensity where we maintain 70-80% of our maximum heart rate, or more accurately, when we keep our blood lactate level below 2.0 mmol/L. In this low intensity zone we are able to keep a conversation but it’s not comfortable, and we would prefer not to talk.
Why?
During Z2, our mitochondria, the “energy makers” of our cells, work at their highest workload. Therefore, by training in this zone, we increase the number of our mitochondria while eliminating non-functioning ones through a process called mitophagy. This is important because one of the hallmarks of aging is a decline in the number and quality of our mitochondria. That’s why we need to use our mitochondria, otherwise, we lose them.
Healthy mitochondria can convert both glucose and fat into energy; this ability is called “metabolic flexibility.” Generally, we can use glucose for energy in different ways, but fat can only be converted to energy in the mitochondria. A study showed that sedentary individuals had no ability to use their fat, only glucose, which means they were metabolically inflexible.1 This increases the risk of fat accumulation and, consequently, increase the risk of developing diseases such as diabetes and cardiovascular disease.
How to do & measure?
We can do zone 2 with almost everything: cycling, swimming, walking - as long we make sure we’re in Z2. I prefer doing my Z2 at the gym on a stationary bike, because It’s more stable and I can better control and measure the intensity and my heart rate.
There are 4 ways to measure whether you’re in Z2, but I use these two ways as they’re most convenient and pretty accurate:
The talk test. If you’re able to keep a conversation, but you prefer not to talk, because it’s hard, then you’re most likely in Z2. If you cannot finish a sentence, you’re pushing too hard.
Measure your heart rate. It should be between 70-80% of your maximum heart rate. If you don’t know your max HR, here’s a formula which can give you an estimate: 208 - 0,7 x [your age]2 For example, I’m 29, and my heart rate has to be between 131-150 during Z2.
The other two ways are: doing a lab physiological test where your lactate level will be measured during a Z2 session or buy your own lactate manometer to measure your lactate level - but it’s expensive and not practically convenient to do finger prick each time you do Z2. Btw we’re interested in lactate, because lactate higher than 2.0 mmol/L indicates a shift into higher intensity zone, and primarily breaking down glucose as fuel, with lactate being a byproduct of this process.
Amount? Track progress?
According to Inigo San-Milán, an expert in the field, around 3 hours per week or four 45-minute sessions are the minimal requirements for most people to see improvement. If you're just starting out, 30 minutes a few times a week is a good beginning, gradually increasing it. Personally, I started that way, and now I aim for four 45-minute sessions each week.
I track my progress through watts per kilogram. On a stationary bike, you see the watts you produce, indicating your power output. It’s a common metrics to track cardio progress. When your watts/kg increase over time, it means you’re improving.
Here’s formula: [watts]/[your weight in kg] = watts pr. kg.
How do I make it more enjoyable?
Since I do my Z2 exercise on a stationary cycling, I can use my iPad to watch movies or series. I also like to listen til podcasts, audiobooks or just put on my favourite music, depending on which mood I’m in 🎧
My favourite resources on zone 2:
🎙️ Podcast: “Iñigo San Millán, Ph.D.: Zone 2 Training and Metabolic Health” from The Drive Podcast (they also did part two here)
📝 Article: A Guide to the Biggest Thing Missing From Your Fitness Routine: Zone 2 Training
📖 Book: “Outlive” by Peter Attia, chapter “Aerobic Efficiency: Zone 2
🍎 Favourite Health Picks
📗 Book: I am finally reading “atomic habits” (I know, I am late to the game). Now I understand why people are so hyped about this book - I am too!
🎬 Video: Great TED talk by Rangan Chatterjee, on importance of treating the root cause and not the symptoms and how chronic diseases don’t “just appear one day” but they slowly develop over years, until things get out of control and then we get a diagnosis.
🎒 Tools: I've been searching for a glass water bottle for a while to reduce plastic usage. I finally found the right one from IKEA for only €1,2 EUR.
🛒 Online grocery: I started doing grocery online, and I love it! It’s such a time and energy saver! I’ll share my whole meal prep system another time.
Thank you for reading! This edition ended up longer than anticipated, but I genuinely hope you've learned something new. If you’ve any questions regarding zone 2 training, feel free to reach out - I’ll try my best to answer.
Until next time, take good care of yourself :-)
Alisa
https://pubmed.ncbi.nlm.nih.gov/28623613/
https://pubmed.ncbi.nlm.nih.gov/11153730/