The longevity stuff that works and the stuff that just sells

A guy I know keeps a chest freezer in his garage set to 45 degrees and climbs into it four mornings a week. He also sleeps about five and a half hours, hasn't picked up anything heavier than a toddler since 2019, and eats lunch out of a gas station. He's optimizing the wrong end of the list.

The public health baseline nobody argues about is still 150 minutes of moderate movement a week plus two sessions of strength work. That's it. That's the price of admission. Everything sold to you above that line ranges from mildly useful to expensive theater, and the shelf at the supplement store gets longer every year because the boring stuff doesn't have a margin.

So let's sort it. What's actually got evidence behind it, what's plausible but oversold, and what you can skip without guilt.

Pills that promise years

There's a whole category now: NMN, resveratrol, various "cellular" blends with a molecule name on the label and a chart on the website. The honest summary is that no supplement has been shown to extend healthy human lifespan. Resveratrol was the darling for a decade and the human results never showed up. Rapamycin and metformin are genuinely interesting and genuinely under study, which is a different thing from proven, and both are prescription drugs with real side effects.

Multivitamins are the fascinating case. Big trials keep looking for a mortality benefit in well-fed adults and keep not finding one. That doesn't make them harmful. It makes them insurance against a deficiency you may not have.

Where supplements earn their keep is fixing an actual gap. Low vitamin D in a northern winter. Iron in a woman who's been anemic and had it confirmed by a blood test. Creatine, which is cheap and has more human data behind it than anything else in the store, and which supports strength work rather than replacing it. Ask your doctor or pharmacist before you stack anything, especially with prescriptions.

If your longevity budget is $180 a month and $170 of it goes to capsules, you've built the pyramid upside down.

Cold water, hot rooms

Cold plunging feels tremendous. It's a legitimate mood and alertness hit, and if standing in a freezing barrel is the thing that gets you out of bed at 5:30, fine, keep doing it. What it isn't is a longevity intervention. And there's decent reason to think dunking straight after lifting blunts some of the muscle-building signal you just paid for, so if you're going to do both, put hours between them.

Saunas have better odds. The interesting data comes out of Finland, where sauna use is common enough to study across a whole population, and frequent users have better cardiovascular outcomes. Observational, which means the people sitting in saunas four times a week may simply be the people with the time, money and health to sit in saunas four times a week. It's a reasonable bet with a pleasant downside. It's not a substitute for the walk.

Cardio without the religion

The zone 2 conversation got out of hand. Somewhere along the line it turned into a requirement to own a chest strap and hold a specific heart rate for 45 uninterrupted minutes while a spreadsheet updates.

The finding underneath all that's real and it's one of the strongest in the field: cardiorespiratory fitness tracks tightly with how long people live and how well. Low fitness is a worse predictor than most of the risk factors people actually worry about.

But the shape of the curve matters. The biggest gains come at the bottom. Moving from sedentary to "walks briskly most days" is worth vastly more than moving from good to excellent. If you're the third-most-fit dad at the barbecue, another interval session buys you very little. If you're winded at the top of two flights, everything is available to you.

Walk fast enough that talking gets slightly annoying. Push a stroller uphill. Take the stairs at work like you mean it. Get one session a week where you're genuinely breathing hard for a few minutes at a time. That covers most of what the chest strap was going to tell you.

The thing that decides how the last decade goes

Strength is where I'd put your second hour. Not for the mirror. For the floor.

Grip strength and leg strength predict all sorts of outcomes in older adults, and the mechanism isn't mysterious. Muscle is the reserve you draw on when you get sick. It's what lets you catch yourself instead of going down. A fall and a broken hip at 78 is the event that ends independence for an enormous number of people, and the training that prevents it's unglamorous and available to you right now.

Two sessions a week. Squat something, hinge at the hips with something, press something, pull something, carry something heavy for 40 feet. Add weight when it gets easy. You don't need six days or a coach or a program named after a Norwegian.

Balance counts too, and it's free. Brush your teeth standing on one leg. If that's easy, close your eyes. You'll find out quickly where you stand.

Sleep, adjusted for reality

Sleep is the lever with the best evidence and the worst advice attached. The standard guidance assumes a household without a four-year-old who gets nightmares. Ignore anything telling you to protect a nine-hour window and a 90-minute wind-down.

What holds up under a real schedule: keep the wake time roughly constant, including Saturday. Defend a six-hour floor like it's a bill you have to pay. Get bright light in your eyes early. Stop caffeine by early afternoon, because the half-life is long enough that the 4 p.m. cup is still working at 10.

And if you snore heavily, wake up unrefreshed, or your wife tells you that you stop breathing, get evaluated for sleep apnea. Untreated, it drives blood pressure and heart problems for decades. That's a doctor conversation, not a gadget purchase.

Food, minus the tribalism

Nobody has demonstrated that keto, carnivore, veganism or any of the rest adds years over the others. What survives across almost every dietary study is unremarkable: mostly food you cooked, plenty of plants and fiber, enough protein, not much ultra-processed stuff, and a body weight that isn't climbing year over year.

Protein is the one most working parents undershoot. Aim for a real serving at each meal instead of a bagel at 7, nothing at noon, and a heroic dinner. Eggs, Greek yogurt, canned tuna, rotisserie chicken, lentils. None of it requires a meal plan.

Where sustainable beats optimal, and where it doesn't

Here's the trade-off I'll concede. Sustainable isn't always enough. If you're 58 and can't get off the floor without a hand, or your doctor just used the word "prediabetes," you need a harder push than three easy sessions a week, and you need it now. Some people also do better with a rigid program than a flexible one, because flexibility is just a slow leak in the hands of a busy person.

But for most men and women with a job, a mortgage and kids who need rides, the program that runs for 20 years beats the program that runs for 11 weeks and ends in a hamstring strain. Three anchors: two lifts and one hard breath session, put on the calendar like a dentist appointment. Walk the rest.

And the highest-yield items aren't training at all. Don't smoke. Wear the seatbelt. Know your blood pressure. Keep the alcohol low. Don't take the last three rungs of the ladder standing on the paint can. Stay close to people who'd notice if you disappeared for a week.

None of that's general medical advice for your specific body, and none of it replaces the person who has your chart. Take the list to them.

Your grandkid is going to ask you to get down on the carpet and build something. The whole project is being able to get back up.