What happens to strength, balance, stamina and reflexes as you age – and what you can do about it

So the rate of decline is largely fixed. What is not fixed is the level you decline from, and that is the whole game. A fitter 60-year-old and a sedentary one may lose capacity at similar rates, but they are falling from very different heights, and across three decades that is the difference between managing your stairs at 85 and not managing them at all. Strength, power, balance and reaction time are all in this category.