1990
JAMA
High-Intensity Strength Training in Nonagenarians: Effects on Skeletal Muscle
Studied: 10 frail, institutionalized volunteers, mean age 90
Ten frail, institutionalized volunteers averaging 90 years old completed 8 weeks of high-intensity resistance training. Average strength gains of 174%, muscle area up ~9%, and walking speed improved 48% — the founding proof that extreme age does not block major strength adaptation.