Maybe you’ve found yourself feeling self-conscious on evening walks while five people pass you (perhaps twice) in their best running forms. Perhaps you spent the day at the lake canoeing or hiking around the beach and later felt guilty for not having made it to the gym. Or maybe you’re frustrated having to mow or rake over the weekend because it means giving up workout time in exchange. Message for the day: shed the guilt, forget the self-reproach, and enjoy a little affirmation.
We’re talking about a favorite of mine: low level aerobic activity. Sure, it can feel all too relaxed, even indulgent compared to the intense stuff. But don’t be so quick to disparage. Low level aerobic activity, I’m here to tell you, is the crucial base of Primal Blueprint fitness (Rule #3 in my book for those of you who are currently reading it). It’s the base, the foundation, the keystone to the big fitness picture.
After all, it was how our good man Grok and his family spent most of their days. Carrying water from the stream. Collecting fire wood, walking through the forests and meadows to gather greens, berries, and other plants. Working on their shelter. Perhaps migrating to another area because of drought, predators or competing tribes. Butchering, building, washing, cooking, dancing, you name it. Some of it was hard work, but it was mostly just continual – the sheer volume of low level activity that characterized Grok’s existence.
If the human body evolved within these conditions, our lives today often leave us as fish out of water. There’s the joke about old time farmers laughing at people who pay to slog away on a treadmill for hours at the gym. Why would anyone pay to run in place like a hamster when there’s plenty of real, hard, useful labor to be done instead? Of course, not all of us have livelihoods that involve enough physical exertion to constitute adequate exercise, and our modern home lives (with washing machines, electric/gas mowers, etc.) don’t require the same labor as they once did. Unlike Grok, few of us built the homes we live in. Few of us till large tracts of land for planting. We generally don’t spend our days scrubbing, hauling or foraging. But it doesn’t matter, ultimately, what form our low level cardio takes. What matters is what happens on the inside.
Let’s take it apart. Low level aerobic activity involves working at 55 to 75 percent of your maximum heart rate. You often see it referred to as “moderate exercise.” (Recently, researchers attempted to define the term more and came up with 100 steps a minute. Their results offer some kind of guidance, but they’re nonetheless a vast generalization.) Heart rate (and the aerobic activity that determines it) varies considerably based on how in shape you are. Here’s what it looks like translated into practical terms. For fit folks, the low aerobic range usually kicks in on the lower end (55%) with a slow to medium paced but easy hike, a slow bike ride or relaxed cardio workout at the gym. An out of shape person would likely hit that same 55% with a stroll around the block. Now flip to the upper limit (75%) of low level cardio, and a fit person is likely looking at a vigorous hilly hike, a somewhat hilly bike ride, or a medium cardio workout at the gym. An unfit person will achieve that 75% with a medium level hike, a minimally hilly and casual bike ride, or an easy-medium intensity cardio workout on the gym equipment. (As for the endurance athletes out there, 80% of your maximum heart rate generally constitutes the upper limit of the “low level” range.)
As I’ve suggested before, our society has come to worship a chronic cardio model as the beacon of fitness. It follows that low level aerobic activity appears to do nothing but fall short – a weak attempt at the “real” thing. Worse yet, it’s an attitude that makes the fitness quest seem like an all or nothing proposition. No pain, no gain. Total bunkum. Sure, the Primal Blueprint model incorporates low level aerobic activity as part of a larger picture along with strength and “sprint” interval training. The PB fitness model, however, is built upon that low level foundation.
Not only is low level aerobic activity the natural evolutionary expectation of the body, it’s flat out beneficial in its own right. It plays an integral role in maintaining weight and metabolic balance. It also builds your base and makes more strenuous workouts possible by toning all the muscles, joints and connective tissue needed for optimal strength training and high intensity aerobic activity. Low level aerobic exercise engages your energy systems and incrementally improves their functioning and efficiency. And while it does all that, it also physiologically and hormonally counters the effects of stress.
Want more? Turns out there are mental health benefits as well. Moderate exercise has been shown to improve the mood and well-being of those with chronic depression. But for all of us, low to moderate level aerobic activity can elevate our mood a good two to four hours after exercise. (And that’s just after twenty minutes or so of activity.) We’ve all felt this one, haven’t we? Letting go of the stress on a solitary hike or evening walk with a friend?
But how much do you need per week for real, ongoing health benefits? While there’s no limit to the benefit of low-intensity aerobic exercise, rest assured that you can experience outstanding health gains by engaging in simply a moderate amount of low-intensity aerobic movement. It shakes out likes this. Go for a minimum of two hours of low-intensity aerobic movement per week. Two hours pales in comparison to Grok’s daily grind, but I know few of us have the time to live a full Grok existence. (That’s not really the point anyway.) Ideally, however, we’d put in more than that two hour bare minimum. I’d consider three to five hours a week of low-intensity an optimal range for modern day folks.
Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.