There comes a point for us all when things have to change. You might not have spent every weekend of your 20s with your head stuck down a toilet, surrounded by empty Maccie’s boxes, but there’s a fair chance that you couldn’t remember the last time you stepped foot in a gym or made a proper meal in your own kitchen. And then, suddenly, you reached 30.

That’s kind of how things went for my friendship group. While I stopped drinking my weight in lager and going out five nights a week at about 25, they carried on – but with more money to splash on their excesses. Then they started turning 30 and one by one, joined a leisure centre, signed up to a half marathon or tried to significantly reduce their drinking. The most ardent smoker is now a vaper and the biggest party animal can be found on most midweek evenings doing lengths down the local pool.

In your 20s, you believe you can live forever and you’re busy simply enjoying having a bit of cash your pocket; your 30s, on the other hand, seems to be about getting your shit in order.

While no one would advocate living like a student forever (the hangovers hit different at 33, for a start), is there any science behind getting our health houses in order at 30? Or is being noticeably fitter and healthier at this age just a societal milestone that many of us feel compelled to meet? To find out, we’ve roped in Alex Davies, UK head of personal training at Virgin Active.

Davies tells Strong Women that many of his clients at Virgin Active are over 30, and that they tend to be “looking to change, adapt or add to their lifestyle for whatever reason”. He says that those motivations are usually quite bespoke to specific age groups, but at 30, they tend to revolve around:

• Signing up to a sporting event like a race as a personal challenge
• Having kids and needing to keep up with them
• Wanting to have children, so getting in the best possible physical condition
• Wanting to improve body confidence by improving metabolism (which starts to slow in this decade)
• Looking to be part of a community and making new friends 

Of course, these goals might apply to a 21-year-old, as they might to someone in their 50s. The humble aim to get healthier and stronger is, however, a lifelong project.

It’s easy to think that 30 is just a bit too late to get seriously fit. Most professional footballers are coming to the end of their careers by 30 and Olympians barely make it much further. Influencers seem to be getting younger and super-fit celebs have been working out for years. 

In reality, however, your 30s are the perfect time to start a fitness journey – and make significant strides. 

The fastest marathoner in the world – Sifan Hassan – ran this year’s Chicago marathon in an eye-watering 2:13:55 (more than two hours faster than the average woman) aged 30. Katie Taylor, possibly the best-known female boxer in Europe is 37. Lioness Jill Scott was 35 when she retired last year. And that’s just the professionals – think about all those women lifting their squat PBs or running their fastest 5k. The average age of UK Parkrunners is 40.5.

From a science point of view, we reach peak strength in our 20s; power and strength start to decline for both sexes by our early 40s. After that, we lose muscle mass at a rate of around 5% per decade.

That might sound slightly depressing, but the good news is that exercise can stave off and even reverse muscle loss. And it kind of doesn’t matter what type you do. A study of people aged 65-94 found that doing resistance exercises three times a week can increase muscle strength over a 12-week period. And people who do cardio regularly don’t seem to lose muscle mass as they age, either; a study of 125 cyclists aged 55 to 79 found that older people don’t lose strength, fitness or immune health as they age.

It’s also worth saying that if you haven’t really trained before your 30s, then you’ll probably continue to build muscle in your 40s as you gain more confidence. An amazing example is Joan MacDonald, the incredible 78-year-old who only started exercising at 70 and who could probably beat most of us in an arm wrestle. 

Beyond chasing PBs or working towards a specific goal, there are real benefits to getting fitter at any age – and the sooner you do it, the better off you’ll be in the long run.

As Davies says: “Why can’t someone over 30 stand on a lifting platform for the first time and do a deadlift personal best again and again? Why can’t a 60-year-old do the same? There’s no reason why not.” 

Now, all this is super positive, but we’ve only been talking about fitness. The other side of the equation is nutrition, and that’s often the hardest health nut to crack. Lots of PTs and influencers subscribe to the whole ‘you can’t out-train a bad diet’ mantra, and while that might sound like good old diet culture, it’s actually kind of true.

A study published in the British Journal of Sports Medicine found that high levels of physical activity don’t mitigate the dangers of having a poor diet. Researchers looked at the independent and joint effects of diet and physical activity on cardiovascular disease, cancer and all-cause mortality, using a sample of 360,600 British adults. It found that people who had high levels of physical activity and a high-quality diet (ie five fruit and veggies a day) reduced their mortality risk by 17% from all causes and 27% from certain cancers, compared to those who were physically inactive and ate poorly.  

Crucially, doing more exercise won’t significantly reduce your risk of dying earlier if you’re still eating a rotten diet. “Some people may think they could offset the impacts of a poor diet with high levels of exercise or offset the impacts of low physical activity with a high-quality diet, but the data shows that unfortunately this is not the case,” explained Melody Ding, an associate professor at the University of Sydney’s faculty of medicine and health, member of the Charles Perkins Centre for chronic diseases and the lead author on the study. 

She added that her research “reinforces the importance of both physical activity and diet quality for achieving the greatest reduction in mortality risk”. 

While a few studies have linked increased exercise with having a healthier gut microbiome (with more good bacteria, for example), there’s far more compelling evidence to suggest that what we eat impacts our guts and overall health far more than movement. 

Exercise and a balanced diet are both crucial for different things. You’re exercising for heart health, healthy bones, strong muscles and lifelong mobility; what you eat can help to fuel that activity and help ward off bugs and certain diseases. And the best bit is, it’s never too late to start improving both.

Images: Getty