Some worry that training really hard might actually make you die younger. Like, if you’ve been pushing yourself since you were twelve or fifteen, and you keep it up for twenty years trying to hit that elite level—does that come with a cost? But then you remember how adaptable the body is. You really are optimizing it for performance. Sure, there are always outliers where things go wrong, but if you look at the big studies—like the ones on French Olympians, or those that track Olympic athletes from all over—you get a very different story.
Take cardiorespiratory fitness, which is basically your body’s ability to take in oxygen at max effort. They measure that with VO2 max. People at the elite level, like the top 2% for VO2 max, actually see an 80% reduction in all-cause mortality compared to people at the bottom. Eighty percent. And even if you’re just “high,” not elite, you still get around a 20% mortality reduction compared to the elites. In other words, the better your VO2 max, the longer you live, pretty much across the board.
On the flip side, people with low VO2 max have the same or even higher mortality risk as folks with hypertension, diabetes, or who smoke. Being sedentary is basically a disease by itself. I really think we should start talking about it that way, because the risk is just as high as with other diseases we already acknowledge.
What actually counts as sedentary? In these studies, it’s usually someone who gets no leisure-time physical activity at all. They don’t play sports, go to the gym, run, nothing. Maybe they get up, shower, walk to the kitchen, go to work or school, but that’s it. They might hit a thousand or two thousand steps a day, max. Even walking the dog doesn’t count much—most people stroll, they’re not power-walking, and they’re stopping all the time. It’s not intense enough to make a real difference.
Honestly, I think the whole “10,000 steps a day” thing is overrated. It takes forever, and if you’re walking slowly, it doesn’t do much. I’d rather people focus on at least 10 minutes of vigorous exercise a day. There’s even evidence that doing bodyweight squats every 45 minutes during the workday is better for glucose regulation than a single 30-minute walk. So yeah, the intensity matters more than the step count.
There’s this classic study by Dr. Ben Levine—he’s a legend in exercise physiology—where his mentors took ten guys and put them on complete bed rest for three weeks. Seriously, they didn’t even get up to use the bathroom; they had catheters. Full-on sedentary mode. After three weeks, their cardiorespiratory fitness tanked.
But here’s what’s wild: Thirty years later, they found those same guys and measured them again. Turns out, those three weeks of bed rest did more damage to their cardiovascular fitness than thirty years of normal aging. Let that sink in—three weeks of total inactivity was worse than three decades of getting older. That’s how important movement is. Cardiorespiratory fitness is probably one of the best markers for longevity we have.