Stem cell exhaustion
The reserve that repairs your tissues, and how it thins out.
Stem cells handle the renewal and repair of our tissues: muscle, skin, gut, blood, bone. With age their number falls and, above all, their function declines. The body's regenerative capacity erodes.
This is why a wound takes longer to heal at 70 than at 20, why muscle rebuilds more slowly, and why tissues end up losing ground with every insult.
What this pillar covers
Muscle and satellite cells
Muscle's regenerative reserve, its dependence on strength work, and why sarcopenia sets in without it.
Regeneration and fasting
How cycles of prolonged fasting restart stem cell activity across several tissues.
Neurogenesis and BDNF
The adult brain retains a capacity for renewal: what supports it, and what shuts it down.
Skin, bone, cartilage
Wound healing, bone density, osteoarthritis: the regeneration of structural tissue and the levers that work.
Why it matters
This is the hallmark of independence. Your capacity to repair decides how you absorb a fall, an operation, an illness. At 40 you do not notice it; at 75 it decides everything.
It is also a hallmark where inaction costs a lot, fast. Unused muscle disappears, and with it the reserve of cells able to rebuild it. The good news: demand brings it back, at any age.
Regenerative capacity is not preserved by resting. It is maintained by use, or it fades.
Where to start
Load the muscle
Two strength sessions a week with a genuinely demanding load: the strongest regeneration signal there is.
Supply the building blocks
Enough protein, spread across the day, without which the training signal cannot be acted on.
Build in cycles
Alternate demand and recovery, and leave room for fasting periods: regeneration needs both halves.