There's a question I ask almost every patient before surgery, and most of them think it's small talk.
"Can you climb two flights of stairs without stopping?"
It sounds like something you'd ask a neighbor. It's not. It's one of the most important questions in my entire pre-op assessment.
Because before I put someone to sleep, I need to know what their heart and lungs can actually do under load, and that one homely question tells me more, faster, than almost anything else in the chart.
Last month I asked it twice in the same morning.
The first patient was a 58-year-old who paused, did some math in his head, and said, "Honestly? I'd have to stop halfway. Maybe twice." He wasn't being dramatic. He drives everywhere, sits all day, and hasn't broken a sweat on purpose since the Clinton administration.
The second was a 71-year-old woman who looked almost offended by the question. "Two flights? I walk hills with my sister every morning. We do the cemetery loop. It's three miles."
On paper (bloodwork, blood pressure, the usual boxes) these two didn't look all that different. But I can tell you which chart made me relax and which one made me plan.
And here's the part that should stop you mid-scroll: the thing that question measures doesn't just predict how someone does in my operating room. It predicts, better than almost anything we know how to measure, how long they're going to live.
The number nobody checks
The formal name for what I'm getting at is VO2 max. Strip away the lab coat and it's simple: it's the size of your engine. How much oxygen your body can take in, pump around, and actually burn when you ask it for everything it's got.
You've had your cholesterol checked. Your blood pressure. Maybe your blood sugar, your vitamin D, your thyroid. Somebody, somewhere, has probably measured your body fat.
Almost nobody has ever measured your engine.
Which is strange, because when researchers follow huge groups of people for decades and ask what best predicts who's still alive at the end?, engine size sits at or near the top of the list. Study after study.
Being in poor cardiovascular shape rivals or beats the famous villains: smoking, diabetes, heart disease. Going from the worst-fit group to even below-average fit is associated with a bigger drop in death risk than almost anything a prescription pad can do.
Read that again. The gap between "unfit" and "kind of fit" is one of the most powerful health moves that exists. And it's not on your lab report.
We screen relentlessly for the numbers that are easy to draw from a vein. The number that matters most, you have to earn.
Why the engine is everything
Here's the way I've come to think about it, standing at the head of the bed.
Life keeps a schedule of stress tests for you, and it doesn't publish the dates. Surgery is one; that's the version I see. But so is pneumonia at 74. A bad flu. A broken hip. A season of grief that wrecks your sleep and floods your system.
Every one of these events walks up to your body and asks the same question I ask in pre-op: how much do you have when I demand everything?
A big engine answers easily. It has capacity to spare. The hit comes, the body surges to meet it, and there's still room left.
A small engine is already running near its ceiling just getting through a normal day. When the demand spikes, there's nothing left to give. That's when a routine illness becomes an ICU stay. That's the difference I can feel in a case before the first incision.
The cruel part is that engine size, like strength, leaks away quietly, a little every year you don't use it, so a 45-year-old with a neglected engine is already living off a shrinking reserve and can't feel it yet.
The merciful part is that it's trainable at any age. The engine doesn't care how old you are. It only cares whether you ask it to grow.
What actually grows it
This is where I get to disappoint the internet, because the answer is not a protocol with a name.
Most of the work is almost insultingly plain: regular, unglamorous cardio at a pace where you could still talk but wouldn't enjoy it. Brisk walking that's actually brisk. Hills. A bike. The cemetery loop with your sister. Volume and consistency do the heavy lifting, literally hours a week of just moving with intent.
And then, on top of that base, a little bit of the hard stuff: once or twice a week, a handful of minutes where you push near your ceiling, intervals up a hill, hard minutes on a bike, because the ceiling only rises when you visit it.
That's it. That's the whole secret. No device, no subscription, no powder.
As a doctor I'll say it flatly: exercise is medicine. It's the most potent longevity drug I'm able to recommend, and the dark joke of my profession is that I can't prescribe it into anyone. You have to fill this prescription yourself, on foot.
The strongest predictor of how long you'll live isn't waiting in your bloodwork. It's the size of the engine you've built, and you can start building it this afternoon.
The bottom line
I want to be careful here, because numbers like this can turn into another stick to hit yourself with, and that's not the point.
You don't need a lab test or a mask hooked to a cart. The two-flight question works fine at home. Climb them. Pay attention.
If you get to the top with plenty left, good. Protect that. If you're stopping halfway, that's not a verdict. It's the most useful piece of health information you've gotten all year, and it's completely, provably changeable. The people who benefit most from training the engine are precisely the people starting furthest back.
And no, a great engine doesn't make you bulletproof. I've seen fit people get terrible diseases, and I've put plenty of lucky, sedentary 90-year-olds to sleep. Biology keeps its own counsel.
But across a whole population, over decades, the engine is the closest thing to a crystal ball we have. I'd rather you spend your effort there than on the eleven supplements currently riding in your cart.
So here's my question for you this week: When was the last time you climbed two flights of stairs without stopping, and if the honest answer worries you, what's the first hill you're going to walk this week?
Reply and tell me. I can't write back to everyone, but I read every single one.
That's all for this week.
See you next Saturday.