So the clocks have gone back and months of long, dark evenings and cold weather lie ahead. But that doesn't mean you have to stay curled up on the sofa until spring.
1. Get kitted out
You know the old saying: there's no such thing as bad weather, just bad clothing.
Just 25 minutes of brisk walking each day can add up to seven years to your life – and halve risk of dying from a heart attack, according to a new study presented at the European Society of Cardiology.
So if a good pair of walking shoes and a waterproof jacket are all that stand between you and a longer life, it's probably time to shell out in the autumn sales.
Nine ways to get more out of your walks
2. Head for cover
Still can't face going for a walk in the pouring rain? That's easily solved: go for a walk indoors instead.
A few suggestions? Take a tip from the US and try mall-walking: you can boost your fitness and burn plenty of calories by taking a brisk walk around your nearest shopping centre. (You could even buy some new walking shoes while you're there, of course.)
Or try a cultural activity: you can cover a lot of ground while taking a tour around a gallery, museum or stately home.
Discover the best art galleries outside London
3. Beat the crowds
Yes, it was nice to go for a refreshing swim in your local pool or head off for a coastal stroll during summertime.
The only problem? Everywhere was packed. But now the kids are back at school and the tourist season has ended, pools, parks and beaches are much quieter – so you have the perfect opportunity to take full advantage of the off-peak peace.
Learn more about how swimming boosts your health and fitness
4. Try something new
Autumn gives us all a chance to discover that 'back to school' feeling – without being obliged to learn algebra or wear a horrible uniform, of course!
Now's a good time to try a new indoor fitness activity – yoga, pilates, badminton, bowls or whatever you fancy – with many six-week beginners' courses starting up again after the end-of-October half-term.
Classes are also likely to be a lot less oversubscribed now than they are in January, when the 'New Year's resolution' brigade bowl up!
Learn more about yoga
Find out more about pilates
5. Stick at it for two months
Another good reason to start a new fitness activity now, rather than waiting until the depths of winter? It takes a while to form new habits: in fact, it takes an average 66 days for a new healthy behaviour to become automatic, according to a study published in the European Journal of Social Psychology.
So start going to that yoga class now, and in two months' time – when the weather's grim and light levels are at their lowest – it'll come as second nature, so you'll stick at it.
More ways to boost your willpower
6. Give yourself a short-term incentive
So it's warm and snuggly in bed – and the last thing you fancy doing is getting up to go for a swim?
The trick could be to offer yourself a little post-workout treat, such as a trip to your favourite coffee shop or an indulgent hour on the sofa watching TV.
Yes, keeping healthy should be incentive enough – but we're only human, after all, and research has shown we're more likely to adopt good habits when a tangible reward is dangled in front of us. For example, obese people are more motivated to lose weight when there's a cash incentive, according to a study at Carnegie Mellon University in the US.
Saga Health Insurance gives you control of your own healthcare needs, and peace of mind you’ll receive prompt treatment. Find out more about our cover.
7. Set yourself a goal
Another big incentive, of course, is to give yourself something to aim for. It could be reaching a target weight, lowering your blood pressure to a healthy level or entering an event, such as next year's Race For Life series. Whatever you choose, striving towards this goal will motivate you throughout the winter.
8. Come dancing
Over the past 12 years, autumn has traditionally become the time of year when we all fantasise about discovering our inner Fred or Ginger, thanks to Strictly Come Dancing.
So why not stop fantasising and actually do something about it this year? There are plenty of beginners' dance lessons in pubs, clubs and leisure centres across the UK.
Whether you opt for Salsa, tap or even Zumba, it will give you a great cardiovascular workout and can help build stronger bones – and it's also a great opportunity to make new friends.
Find out more about how to dance yourself fit
9. Make Christmas part of your workout
Another incentive to keep moving is that you'll get much more done in the busy pre-Christmas period.
Doing all the shopping, putting up the decorations and delivering cards and presents on foot – or by bicycle – will give you a good workout (and save you money).
And, when you meet up with friends and family over the holiday period, you could suggest incorporating a walk or fun activity, such as ten-pin bowling, into the occasion, instead of sitting around indoors.
How to fight Christmas weight gain
10. Up your activity levels at home
Let's be realistic: despite your good intentions, chances are you'll be spending more time indoors over the next few months.
However, that doesn't mean your activity levels have to drop – as long as you remember to build some incidental exercise into your day.
A few tips? Use a cordless phone and stand up and walk around whenever you're on it. You could always deliberately leave it in another room so you have to hurry to answer it when it rings, too.
And, if you've got a spare 10 minutes, try the British Heart Foundation's living room workout.
How to become more active without noticing