It’s the first sporting injury of my life, sustained while I was training for a longer out-of-town cycle with BellaVelo. Another cyclist wearing tracksuit bottoms (this is relevant) undertook me, and his pocket hooked on to my drop handlebars. I didn’t realise – I just thought, well that’s bad luck, to lose control of your steering at the exact same time as the guy in front pulls his trousers down – and wham, the next thing I knew, my shoulder hit the pavement. The thing after that, I had one useless arm.

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A week later, I couldn’t lift a pint. I want to say something bolstering about recovery in your 40s, something that makes the human body sound mysterious and adaptive, but the phrase I’m looking for is “not as good”. Everything that goes wrong is wronger, and righting it is slower. “Around your late 30s, you’ve peaked, and recovery will get slower,” osteopath Hashim Saifuddin explains. “Your heart and lung capacity are decreasing, very slowly, which reduces your output.” Plus your inter-vertebral discs don’t rehydrate so well, so all the shock they would have absorbed goes into your bones instead.

The sports injury specialist Paul Argent is a bit more brutal. “Past 28, we’re in a battle. People always think, if you smash yourself, you’ll adapt; the harder you go, the better the outcome. That is not the case. The harder you go, the worse the outcome. It’s not sexy, but it’s the truth.”

They’re called “weekend warrior injuries”. You don’t need a bike – all you need is a sedentary day job and a stupid attitude. The injuries Rachael, a physio, sees are from cross fit, running and rowing, but it’s not the activity so much as the intensity. “Injuries in this age group are all about people training too quickly, doing things their bodies aren’t ready for.”

Fit in my 40s: ‘Give up this fitness tracker? I’ll die first’ Read more

People think training for a marathon means doing something that’s a bit like a marathon, but Paul says, “that’s like, instead of working on a car to get it ready for a race, you’re just driving it”. You have to build your strength, and that is a slower and deeper job than just pushing yourself. And warm-ups are of limited use. “Sitting at a computer, that’s a very cold state,” Hashim says. “High-intensity exercise is a very hot state. A warm-up isn’t really going to take you from one place to another.” You have to consider the contrast between your regular day and your exercise, and not make it too great.

Surely people who do too much are healthier than people who do nothing? “Yes and no,” Hashim says. “People who do nothing will have cardiovascular problems. People who do too much will have muscular-skeletal problems. But internally, their bodily systems will be healthier.” But what does “healthy” mean? According to Paul, “it’s being able to do what you need to do painlessly, sleep well and feel good when you wake up.”

This week I learned

Six weeks is the catch-all healing time for muscle tears and sprains and suchlike. But there’s no guarantee you’ll actually be better then.