The news that – according to a recent survey of 2,000 people in the US – people feel they are too old to start exercising at 41 would raise a few eyebrows in Fauja Singh’s house. He took up running at 84, and ran his first marathon aged 89. He went on to run a further seven marathons, including one at age 100 So if you have just turned 41 and think you’re too old, think again.

Rangan Chatterjee, a GP and author of Feel Better in 5, says exercising in our 40s is vital. “Exercise will help no matter what age you are,” he says. “But once we’re over 30 we start to lose muscle mass each year – and lean muscle mass is one of the main predictors of longevity. So exercise, especially strength training, becomes arguably more important than ever.”

The main reason people gave for not exercising after turning 41 was a lack of time. I know the feeling. I’m 45, I have a job and three children, but I run regularly – including 10 ultramarathons in the past three years. The best time for me to fit in my runs is early in the morning. But it’s not easy when the alarm goes at 6am on a winter’s day.

What you need to put front and centre in your mind at that moment is the post-exercise buzz. Remember that? Sitting down to a big breakfast, glowing with energy after your workout, as the rest of the world is still emerging from sleep.

If you can’t get yourself moving, try to find a running buddy or join a group. From running to yoga to a local football team, it’s so much easier to get out there if you know someone is waiting for you.

Humans are creatures of habit, so making exercise part of your routine – however you can fit it in – also makes it easier, as then you will do it without thinking. You won’t regret it. Exercise has been proven in countless studies to improve mood, alertness, memory and happiness, as well as physical wellbeing. Your age – whether 21, 41 or 91 – has little to do with it.