Cardio Zone 2: A Deeper Dive
The Grandaddy of Longevity Training
Zone 2 cardiovascular training is the foundation of all movement training, which I have discussed in previous articles, including the “5 Aspects of Physical Training.” Zone 2 is the fundamental activity our ancestors did to find food while our bodies were evolving into what they are today. And while they mainly walked and ran to support their hunter-gatherer lifestyle, we have supplemented the kinds of activities we can do for Zone 2 training today with workout routines, cardio machines, and other useful knowledge and equipment.
The keys to effective Zone 2 training are steadiness and duration, moving at roughly 60-70% or your maximum heart rate (MHR). Zone 2 is not meant to be taxing but should be done just below the level that it feels like you’re taxing your body. That level is the threshold between aerobic and anaerobic energy. At this threshold, the body switches from burning fat and oxygen in Zone 2 (aerobic activity) to burning glycogen and lactate for a short-term boost (anaerobic activity, the kind of short burst you do for power in HIIT training). A helpful metaphor is to think of longer-burning coal versus quicker-burning gasoline.
We want to stay just below that “power boost” threshold for Zone 2 training, so our body will continue to function normally during the activity, for example, digest food, continue the maintenance work of the immune system, and take advantage of all the wondrous things that our circulating blood provides. (Zone 2 training increases blood circulation.) On the other hand, once you are in anaerobic territory (for example, during a HIIT workout) those processes start to shut down as the body prioritizes the “fight or flight” energy that was required to escape or confront danger in the Stone Age.
Zone 2 Takes Up Much of My Training Time, Under Steady Conditions
I do Zone 2 training 2-3 times per week, either walking on a treadmill or riding a stationary bike or using a rowing machine in the gym (sometimes doing all 3 activities in a week). My sessions last from 60 to 90 minutes. I’m usually not tired after them, at least not so tired that I feel depleted, and many times I can follow up my Zone 2 activity with a short strength-building workout or yoga session. I also sometimes do a long walk in a park, not a hilly one, with our dog as a Zone 2 session. In a recent Zone 2 article, author Peter Attia recommended that you do Zone 2 training in as steady an environment as possible, preferably a gym, to ensure that your heart rate doesn’t fluctuate too much and to ensure you stay in Zone 2 for the duration of the session.
During these sessions my heart rate is around 110 (69% of my MHR of 160, or at the higher end of being conversational), and I aim to stay as steady at that rate as possible. If it starts to go up, I slow down or decrease the resistance or incline.
It is important to note that I didn’t start at this level. My first sessions in the gym that I write about in my book, which were guided by the book Younger Next Year: Live Strong, Fit, Sexy, and Smart—Until You’re 80 and Beyond, began with less time and a lower heart rate. If you are just starting out, 2 sessions of 30 minutes each per week will start to give you the benefits, depending on your general level of health, of course. (Start out with less if you need to.) What’s important is that you feel the benefits and become comfortable with the routine of regular training, which is where even bigger benefits kick in over time.
The benefits of Zone 2 training and increased circulation in general can’t be overstated. We are still learning more about it all the time. But the known benefits are increased energy, increased aerobic capacity, lower inflammation, better metabolism, lower insulin resistance, increased immune function, better sleep, lower risk of injury, and lower blood pressure. Better circulation also bathes all the parts of you in nourishing, detoxing, blood, that’s eyes, ears, all your organs, brain, skin, and everything else. Perhaps most importantly, although the exact links are not known, is the effect it has on all-cause mortality (ACM), which refers to the risk of death due to cardiovascular issues, dementia, cancer, diabetes, falls and accidents, and other health issues. Regular Zone 2 training has been shown to reduce ACM by as much as 30-40% in virtually every reliable study conducted.
So, do yourself, your body, your loved ones, and your life a favor. Start a Zone 2 training program, or maintain the one you’re on, and enjoy the wonderful feeling of being alive!
