There’s a tension in bone health advice that nobody addresses directly. We know loading your skeleton is what makes it stronger, so we want to lift heavy. We also know that a spine with osteoporosis in it is fragile, and slouching under load can cause a vertebral fracture. So which is it?
The answer, mostly, is posture and tension – and I learned the mechanism from Dr. Stuart McGill, who is about my favorite doctor on the lower back. I took a course on lower back injuries ten years ago and his book was the textbook for it. (He also has an epic mustache, if that sort of thing matters to you.)
His book was the first place I read that properly engaged muscles counterbalancing each other and pulling against each other, a bit like tug-of-war, take a large share of the load off your bones.
Picture it. You’re loose and relaxed, loosey-goosey, and somebody stacks weight on you. Your bones are holding all of that weight. Now picture yourself braced and tight, everything as tense as it can get, and the same weight goes on. Your bones are taking far less of it – potentially half as much or better – because your muscles have taken over the load.
And then the bones’ job changes. Instead of an external force resting on your skeleton, it’s the internal force of your muscles pulling on the skeleton at their attachment points. That’s a different kind of load, and it’s the kind that builds bone.
Which is why bad posture under load is genuinely risky. It isn’t only that you’re in a weaker, more vulnerable position, though you are. It’s that more of the weight goes to your skeleton, because the muscles that should be sharing it aren’t engaged. Good posture engages them automatically, because the muscles are what’s holding you in that position.
So here’s a rule of thumb that will serve you on almost any lift: the more tension, the better. Can I get more tension into my arms? Yes. My core? Yes. My thighs, my feet, my hands? Yes. Every bit of tension you add puts more of whatever you’re doing into your muscles and less into your skeleton – and the strong muscles pulling on your bones are what’s going to build them, in exactly the right spots, rather than the load landing wherever it happens to land because you’re relaxed and in a weird position.
From our monthly community Q&A inside Stronger. Faster. Younger. If you missed the bone density clip from July’s Q&A, this one picks up right where it left off.
