The maximum lifespan of humans is fixed and subject to natural constraints. With rare exceptions no one has lived beyond 115 years.
Adam Rifkin stashed this in Longevity!
Source of the 1-second workout to increase a human's lifespan:
How long can humans live? 115 years, says this meta-study of life spans:
Study in Nature: Evidence for a limit to human lifespan
Driven by technological progress, human life expectancy has increased greatly since the nineteenth century. Demographic evidence has revealed an ongoing reduction in old-age mortality and a rise of the maximum age at death, which may gradually extend human longevity. Together with observations that lifespan in various animal species is flexible and can be increased by genetic or pharmaceutical intervention, these results have led to suggestions that longevity may not be subject to strict, species-specific genetic constraints. Here, by analysing global demographic data, we show that improvements in survival with age tend to decline after age 100, and that the age at death of the world’s oldest person has not increased since the 1990s. Our results strongly suggest that the maximum lifespan of humans is fixed and subject to natural constraints.
More specifically there are genetic/cellular constraints. The natural world is survivable beyond 115 years. There are many animals on the planet that go beyond that mark. DNA replication errors are stochastic. No one rolls the dice forever without losing, but it's certainly possible to make all six sides read 1. In biological terms, if we figure out all the genetic pitfalls and keep them all stable, we could conceivably live for centuries.
It is time to classify biological aging as a disease.
Genesis 6:3 NIV Then the LORD said, “My Spirit will not contend with humans forever, for they are mortal; their days will be a hundred and twenty years.”