Somewhere around the age of fifty, most people I talk to have quietly stopped asking how long they will live and started asking a different question: how long will I be able to do the things I want to do.

That is the better question. It is also a question you can actually train for.

The number that stopped being interesting

Life expectancy is one of the great achievements of the last century. It is also, on its own, close to useless as a personal goal. Nobody I have ever met wants an extra eight years if those eight years are spent unable to get up the stairs.

Health span is the useful measure. It is the part of your life in which you are functionally well: strong enough, mobile enough and steady enough to do what you want without having to plan around your body. For most people in the United Kingdom there is a substantial gap between the two numbers. Years of life, at the end, in which the length is there and the quality is not.

I am not raising that to frighten anybody. I am raising it because the gap is not fixed. It moves, and what moves it is largely how you spend your forties, fifties and sixties.

What actually declines, and how fast

The honest version is this. From roughly your mid thirties you lose muscle mass unless you give your body a reason to keep it. Bone density follows a similar path, and for women it drops more sharply around the menopause. Balance quietly degrades, largely because most adult life stops asking anything of it. Aerobic capacity falls too.

None of these fall off a cliff. They drift. That is precisely why they are easy to miss, because you adapt around them without noticing you are adapting. You stop sitting on the floor because getting up is a nuisance. You take the lift because the stairs are a bit much today. You stop carrying both bags in one trip. Every one of those is a small, sensible accommodation, and collectively they are how a person ends up in their seventies unable to do things they could have done all along.

The thing worth knowing is that every one of them responds to training. Not just slows down. Reverses, at least partly, at pretty much any age. There is good research on strength training in people in their eighties producing meaningful gains in muscle and function. Eighties. If it works then, it works considerably better now.

The second half of life changes the question

In your twenties, training is mostly about what you want to look like or what you want to achieve. Fair enough. Nobody needs a philosophical justification to want to be able to do ten pull ups.

In the second half of life the question turns practical, and it turns specific. It is no longer “do I want to be fit”. It is:

Can I get up off the floor without using my hands?
Can I carry the shopping up two flights without stopping?
If I trip on a kerb, can I catch myself?
Can I still reach the top shelf, and turn far enough to reverse the car?
Can I get through a long day on my feet and not pay for it for three days afterwards?

I like these questions because they are checkable. They are not abstract wellness. You either can or you cannot, and if you cannot, that is a training problem with a training answer.

Why independence is the real prize

If I had to reduce all of this to one word it would be independence. Almost everything people say they want from the second half of their lives comes back to it. Travelling without worrying about it. Picking up grandchildren. Gardening. Living in a house with stairs. Not becoming a logistical problem for the people you love.

Independence is downstream of four things: strength, cardiovascular fitness, mobility and balance. That is the whole list. It is not a long list and it is not a complicated one, which I think is the part that surprises people most.

Balance in particular is worth naming plainly, because it sounds trivial and it is not. I mean it literally: not falling over. A fall is how a very large number of otherwise healthy lives change direction permanently. Balance is trainable, it improves quickly, and it costs almost nothing in time. It is probably the highest return work most people over sixty are not doing.

The amount of work involved is smaller than you think

Here is the part I most want people to hear, because it is the part that stops people starting.

Meaningful progress in all four areas is possible on thirty minute workouts, two to four times a week. That is the honest figure. Not two hours a day, not five sessions a week, not a life rearranged around a gym. And in a genuinely hectic week, ten minute workouts are a real thing rather than a consolation prize. They keep the habit alive, and the habit is what compounds.

The reason it works out so economically is that the four pillars overlap. A well built strength session already asks something of your balance. Mobility work sits inside the warm up rather than needing its own hour. You are not running four programmes, you are running one programme that covers four bases.

What this looks like in practice

If you take nothing else from this, take these three.

Start with what you can do, not what you used to do. The version of you from 1994 is not a useful reference point and comparing yourself to him will only make you quit. Where you are now is simply the starting line, and it is not a verdict on anything.

Pick something you will still be doing in March. The best programme is the one that survives contact with a busy week, a cold snap and a fortnight of feeling unmotivated. That usually means shorter, closer to home and less dependent on equipment than people expect.

Aim at function, not at numbers. The point is not the weight on the bar. The point is that getting off the floor stops being a manoeuvre you think about.

Life span is not an effective goal in itself. Health span is: not just the length of it, but the quality. And unlike a great many things about getting older, this one is genuinely within your control.

If you would like to talk about where you are now and what you would like to be able to do, the first consultation is free.

Health span, not life span