Never feel a day over 21? Or do you worry your body's ageing faster than it should?
Your lifestyle can greatly impact how youthful you seem, so discover your true physical age by answering our questions about habits.
Don't worry if you come out older than you really are - it's possible to turn back the clock with some easy tweaks. Take the test, tally up your scores and check below for expert tips on lifestyle changes you can make.
Same age or younger?
You're on the right track! Wellness coach Michelle Brewster says there are still some things you can do to maintain it.
"Challenge yourself by setting personal bests or entering a charity fitness event."
Try this: Learn a new kill. It can help form new neural pathways in the brain and make existing ones stronger.
+1 to 3 years older
Introducing weight-training sessions will help you get back on track.
Try this: Why not try eating more purple fruit? Blueberries, blackcurrants and blackberries get their pigment from anthocyanins - antioxidants that help ward off disease.
+4 to 8 years
"Make active choices - go for a jog or try a new exercise class", suggests Michelle.
For better sleep, switch off electronic devices by 9pm and get outdoors daily to help create regular sleep-wake patterns.
Try this: Meditate. Constantly feeling stressed accelerates the ageing process. Search YouTube for free mindfulness sessions, such as Calm's videos.
+9 years or more
"Drink plenty of water and cut down on ready meals and junk food. Eat lean meat, fish, olive oil, nuts and seeds," advises Michelle. Raise your heart rate to 50-70% of your maximum heart rate (220 minus your age) every two days with brisk walking.
Try this: Stand more. Sitting for 10 hours or more per day could age you by up to eight years.
Want more brain teasers? Catch up with all our previous quizzes here.
