Remember the mobility challenge that went viral last year? It goes like this. You’re standing up; you can’t use your hands, so start by crossing your arms across your body. Cross one leg in front of the other. Drop down to sit cross-legged on the floor. From here, get on your knees with your toes behind you. Now pop backwards into a deep squat, the one where your butt is against your heels. Now stand up.

It’s hard, right? Most people can’t do it. And yet you can’t afford to ignore this stuff. Poor mobility can greatly affect your quality of life, making everything from washing yourself to cleaning your home difficult or painful. And, although it may not kill you, it is certainly correlated with early death.

From 2002 to 2011, Brazilian researchers tracked 2,000 people aged 51 to 80 who had taken part in a test requiring them to sit on the floor from standing, then get back up, all without using their hands, knees or arms. Over the following nine years, those who failed this “sitting-rising test”, whatever their age, were five to six times more likely to die earlier.

Mobility is deadly serious, then, especially as you age. But – newsflash, 25-year-olds – the best way to keep it is never to lose it.

“No worries,” as the mobility coach Roger Frampton likes to say. “We can scale it.” The only difference between a beginner and an elite, in mobility, is range of movement. Anything you practise that pushes you to the edge of your range will extend it. If you can get on to the floor without using your hands, say, but can’t get back up, you can give yourself an advantage by sitting on a cushion. This is quite a guerrilla form of self-improvement.

Frampton describes mobility as “usable flexibility”, or flexibility that isn’t coming at the expense of strength. He uses himself as a case study: “When you’re younger, you’re trying to look a certain way. In my mid-20s, I was going to the gym, doing a lot of strength stuff. I was ridiculously tight, couldn’t touch my toes.” When he became a model, they wanted him to look less beefy, and after that his flexibility improved, “and I was almost … gumby, they call it in America. Another term is a ‘white noodle’. You’ll see someone with incredible range, but there’s no power behind it.” It was in trying to reach a state of balance, with strength and flexibility working in concert rather than at the expense of the other, that he turned into Mr Mobility (he is on the web at roger.coach and on TikTok as @rogerframpton).

At first, I couldn’t do last year’s big challenge. Then, just messing about on my own, I could do it after a fashion, but only with my stronger leg crossed in front. In an ideal world, your legs might differ a bit in strength, but they shouldn’t act as if they belong to two different people. To do this, or the sitting-rising test, gracefully, you need to be methodical. Break it down and work on each element. Once you can do the challenge, carry on doing it.

Sit cross-legged

Sit, slouching against a wall, with your feet out straight. Place one foot on your opposite thigh. Bend the other leg and try to sit up as straight as you can against the wall. Then repeat on the other side. You are trying to close the gap between your lower back and the wall, which took me a week (doing the exercise for two minutes a day). It is an incredible stretch and will improve the quality of your cross-legged sit – your back will be straighter, and your legs crossed tighter – but while you’re there, you might notice that, with your legs straight in front of you, your back isn’t straight but is slouching inwards, the curse of working at a desk.

So put a chair within arm’s reach and stand against the wall, touching it with every bit of your legs, down to your heels. Drag the chair in front of you and place your hands on it. That’s exactly the same straight-backed position as you want when you’re on the floor, only you’re relaxing down to find your perfect alignment, rather than trying to pull yourself up into it. You extend it over time by moving your legs further apart. This is another two-minute job, and I could sit straighter after a fortnight.

Do a wall sit

Now you need to work on balance, for which the best starter exercise is standing on one leg with your eyes closed for 60 seconds. This reminds me a lot of going on holiday with my friend just after his catastrophic brain injury, when he had to relearn to walk backwards. All I could think was: “How is he making that look so hard?” It’s good at forcing you to engage a lot of muscle sets, as “you’re working so much more than just your foot,” Frampton says.

The other obstacle will be lack of strength in your glutes, and for this you can do a wall sit – as it sounds, sitting with your back touching a wall, but your bum floating as if on an invisible chair. Again, you can scale up in 15-second increments how long you hold it. Canadian Peter Attia, a doctor and author of Outlive: the Science and Art of Longevity, does the air sit – same exercise, without the wall, with your arms stretched out at shoulder height directly in front of you – for two minutes, which is insanely difficult; but try it for 10 seconds and, God willing, after 17 days you might get to 15 seconds.

Touch your toes

Everyone thinks they can still do it, but that’s probably because it’s a long time since they tried. This will take a month, but only three minutes a day. In the first week, do a leg elevated hinge – put your heel in front of you on a low chair and hinge towards it, with a straight back, for 30 seconds on each leg, three times. Week two, a hip hinge: standing with straight legs, arch your lower back and try to bend at the waist so you’re at a 90-degree angle (but don’t force it: just go as low as you can with your back still arched and not bending your knees) – for three sets of 10 bends. The third week, the same thing, only with a split stance, your weight on the front, straight leg – three sets of eight on each leg. Finally, a week of moving from a squat position to one with straight legs, bending at the waist so your head is level with your knees.

Hang for one minute

I spent ages trying to find a tall enough door and not hurt myself, before I remembered that there are monkey bars in every park. This is good for grip strength, obviously, as well as upper body strength overall, but the best thing is that you can’t mess it up. You have your two arms, and you have gravity, and there’s absolutely no way for these things to interact except the right way. On the downside, it’s pretty hard, and is one of the 11 tests Attia uses on patients as part of the Strength Metrics assessment (the goal is a minute and a half for a 40-year-old woman, two minutes for a 40-year-old man). But you can work up to that in increments as pathetic as you like – five seconds, even.

Sit properly in a chair (and other ways to behave at a desk)

“Your body doesn’t think about the future,” Frampton says. “Your body’s trying to survive the day. It’s not expecting to be around when it’s 90.” I’d asked him why, for any stance that’s habitual to you, does your body always find the worst possible way to do it?

Anyway, at your desk, “try to sit on your legs and not your arse,” Frampton advises. “That way, your back will be flat, your torso will be lifted and your shoulders will fall backwards.”

A simple stretch you can do while still at your desk is to put your arms out behind you, clasping your hands with your palms facing outwards. If you’re really tight in the shoulders, you can start with a bend in the elbows. Hold it for a minute. Something I forgot to mention earlier: you never want to be in pain – it’s not cardio.

Working at a desk, your head is pulled magnetically towards your screen, until you have a curved neck, which, besides anything else, if you carry it over into your walking style, is very ageing. Get into a wall sit, with your pelvis tucked in so your entire back is in contact with the wall; touch your head against it too, and move your chin to point to the ceiling, then draw it back in to your chest. If you’re old enough, you can actually hear your neck making a gristly noise as it straightens. Or maybe that’s just me. I hope not.

On public transport, stand without holding on to anything

You’ll have to brace your core just to keep your balance, and subtly move against the jerky rhythm of the train or bus, but there’s something relaxing about the low brain-stakes concentration. I didn’t get this from an expert; I made it up. It really annoys my kids.

Frampton thinks of the body as “one piece of tissue. It makes sense from a learning perspective to divide it into your abs, your triceps, your chest, your glutes. But then when you’re doing the mobility movements that I’m describing, it almost becomes unhelpful to silo it like that.” Ten minutes a day is enough, but you can never stop, I’m afraid. “You could equally say: ‘When do my teeth just become clean – when can I stop all this brushing?’” Frampton says. “You need to think of this as something you’ll be doing for as long as you’re alive.”