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.
The impact is impressive to say the least. Specific studies have found that it reduces the risk of metabolic syndrome , breast cancer , and death from cardiovascular disease . It also appears to reduce the risk of vascular dementia . But the kicker is this. Low level aerobic activity, research suggests, can decrease overall systemic inflammation  and the risk for the vast array of degenerative diseases that plague our modern society. Skeletal muscle fibers, researchers have found, act as “an endocrine organ.” Working the muscle fibers, it appears , stimulates the production of Interleukin-6, an anti-inflammatory cytokine, which in turn signals and benefits other organs. Don’t you love this? (On the lighter note, low level aerobic activity also decreases the incidence of colds . As we all know in the context of our busy lives, that’s nothing to shake a stick at.)
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.
What does it boil down to then? Simple activity – whatever floats your boat. Dancing (line, club, ballet, etc.), outdoor hikes , pleasant bike rides, vigorous gardening , brisk walks , a light swim, rollerblading in the park, ice skating, yoga , some doubles badminton or tennis, a game of Ultimate , playing  or just mowing the lawn. In short: leading an overall active life by working in low level aerobic exercise into the daily pattern of your life, your relationships and your free time fun. It’s the good life, I’d say.
Now I’ll turn it over to you. Tell me how you make low level aerobic exercise fit into your life and fitness? Have other comments or questions? Shoot me a line, and thanks for reading.