Expert reveals the most exhausting decade of your life and why it's only temporary

An expert study has found which decade of our lives in the most exhausting, though it's probably not be the one you think.

When it comes to what we think of as the most exhausting age, many of us might think of one age in particular.

This is, of course, your teenage years, where your body starts rapidly changing and you're met with the stresses of school, university, and starting work, all while it seems that society wants nothing more than to demonize you for existing.

But the study found that it's not actually your teenage years at all, and nor is it your 20s, despite the struggles of trying to stand on your own two feet during that time.

Okay, so maybe your 30s, when you start to get anxious about getting older, hangovers last days rather than hours, and back pain begins? Wrong again.

Work stresses can become more apparent (Westend61/Getty)

In fact, the study found that the most exhausting decade of our lives is our 40s.

Professor Michelle Spear is an anatomist at the University of Bristol in the UK, and told the Daily Mail that our 40s are the most exhausting time because of two crucial factors.

The first of these is that the way our bodies produce energy changes, so we may not be as bursting with it as we are when we're in our 20s.

This is combined with a time of life where our responsibilities at work and at home also reach their peak.

We might be in more senior positions at work, taking on more responsibility, more demands, and more stress.

Meanwhile, at home, if you have have children in your early to mid 30s then in your 40s is when they will hit becoming a teenager, with all the demands this can bring.

The study looked at both biological and social factors (Maskot/Getty)

So, it's a perfect storm of not as much energy, and more demands on our energy, which she described as a 'mismatch between biology and demand'.

Professor Spear said: "Our bodies are still perfectly capable of producing energy, but they do so under different conditions than in earlier adulthood, while the demands placed on that energy often peak."

She added: "In our 20s, the body is biologically very forgiving.

"Muscle repair is faster, inflammatory responses are shorter–lived, and energy production at a cellular level is both efficient and plentiful."

However, she also emphasized that this can vary a lot from person to person, saying: "Two people of the same age can have very different energy profiles depending on what their bodies are being asked to carry."

And not only that, but as we age, we may also find that this perfect storm passes as well.