Andrew Steele

so what happened in the study? THE RADIATED MICE LIVED SIGNIFICANTLY LONGER they had a 53% LOWER risk of death (HR=.475, p=0.003) than the mice dosed with no radiation!!!

When I was on the ISS for my nearly year long mission, there was a telomere experiment comparing my telomeres to my earth baseline and my twin brother as a control. Hypothesis was they would get damaged and worse due to the environment. Turns out they got better. Initially NASA thought maybe it was due to exercise and diet. After I returned we learned JAXA had a telomere experiment on some small worms the same time I was there. Their telomeres got better too. Never saw the worms doing any exercise. After further study determined it was the radiation.

so what happened in the study? THE RADIATED MICE LIVED SIGNIFICANTLY LONGER they had a 53% LOWER risk of death (HR=.475, p=0.003) than the mice dosed with no radiation!!!

What if the real goal of longevity isn’t Healthspan, but something called Peakspan? New research argues the real target is Peakspan. Peakspan = the years you operate at ≥90% of your peak physical or cognitive ability. Here’s the surprising part: Most human systems peak in our 20s–30s. • VO₂max and lung function peak ~20–25 • Fluid intelligence peaks ~20–30 • Muscle strength peaks ~20–35 • Kidney function begins declining in the early 30s By age 50, most people have already left Peakspan for many systems, even if they’re still “healthy”. This creates a huge Peakspan–Healthspan gap: Years where you are disease-free but already operating below peak capability. The implication is big. Future longevity science should focus less on simply extending life and more on extending the years near peak performance. That means detecting the earliest functional decline and intervening early. AI may help do this by tracking personalized trajectories from wearables, biomarkers, and imaging to predict when someone is about to exit their Peakspan. If we extend Peakspan, we don’t just add years to life. We add high-performance years to human capability.

There are issues with this analysis, and I can tell you the results are unlikely to be robust. If you have an interaction effect, it needs to be pre-specified, and the fact that they didn't specifically test for interaction means that when you put 3 variables into an equation, the effect goes away. The fact that sleep duration is U-shaped is not suprising but the interaction effect probably isn't real and shouldn't be overinterpreted. All the p-values also go away if you do even a modicum of adjustment, and this is with a very large sample.

Regular exercise is linked to slower biological aging - but only in people sleeping 7+ hours. People who slept under 6 hours and exercised actually aged faster.