Brits have the most energy at the age of 31, a study has revealed.
A poll of 2,000 adults found that our energy levels peak in our early 30s as we juggle the demands of busy working and family lives.
After spending our 20s enjoying late nights, junk food and very little exercise, settling down into a career and starting a family during our 30s means we are full of drive with little time to laze around.
But as they approach the end of their working life, Brits can expect to have another surge of energy around the age of 55 as they get reinvigorated by the thought of retiring.
It emerged that more than eight in 10 admit they have the most energy when they have lots to do or are constantly busy.
A spokesman for vitamin firm Healthspan, who commissioned the research, said: ''Everyone would assume that it's our 20s when we are at our most energetic.
''But in reality, while you may have age on your side, busy social lives, late nights and a pretty poor diet can mean the opposite is true.
''In your 30s, you have more on your plate with juggling work and your family lives, but this can actually boost your energy with many people saying the more they have to do, the more energy they have to keep going.''
Psychotherapist Sally Brown added: ''Lifestyle does impact on your energy levels but what came through from this study is that energy is strongly affected by state of mind, and that overall attitude to life and feeling happy are our biggest energy source.
''It could explain why we feel like we have the most energy in our 30s, even though we're also dealing with the biggest drains on our energy from work and bringing up children.
''The study also highlighted a link between stress and energy levels as we experience an energy surge in our 50s, when we are free from the stress of looking after a young family and nurturing a fledgling career.''
The study found 31 is the age Brits are at their most energetic, with half putting this down to it being the time in their lives when they did the most exercise.
Forty-one per cent put their high energy levels in their early 30s down to being at their happiest, and looking after themselves better, while others believe it was thanks to having young children to run around after.
One in ten 30-somethings even describe their energy levels as excellent, compared to just one in 20 over-50s and over-60s who said the same.
It also found those in their 30s get the most exercise - an average of three times a week despite juggling family and work.
And just 12 per cent say they never exercise compared to almost one in five of those who are in their 40s and one in four of over-60s.
Busy 30-somethings also spend the most time working - an average of more than six hours a day - and are tucked up in bed by 10.26pm, earlier than any other age group.
Researchers also revealed that 82 per cent of people find their energy levels start dropping the moment they have little or nothing to do.
Over three-quarters of those surveyed have moments when they feel the need to boost their energy levels slightly and especially at this time of year as things rev up even more.
It also emerged that despite our busy and hectic lives helping to keep our energy levels high, our job is also the biggest drain on them, followed by worries/anxiety and the drain of day-to-day chores and our children.
Plus, one of the biggest energy drains is not a physical illness but depression mental illness such as depression.
Rob Hobson, Healthspan's Head of Nutrition, said: "Research revealed people are aware of using food, diet and lifestyle to boost their energy.
"Having a quick cup of tea or coffee is the most popular way to get a quick boost, followed by having a power nap, drinking some water, going for a walk and eating some chocolate.
"I would agree that taking a little time-out during the day, keeping well hydrated and getting outdoors are great ways to re-energise yourself during the day although I could suggest a number of other healthy snacks to maintain energy levels and avoid mid-morning and afternoon slumps."
Top five energy drains:
3. Day-to-day chores
5. A chronic health or mental health condition
Our favourite energy boosters:
1. Cup of tea or coffee
2. Power nap
3. Drinking water
4. Walking outside
5. Eating chocolate