Suddenly it feels colder outside. Yesterday it was properly wintry. Wind, cold fingers (even in the house) and nasty downpours. As one Tri pal said: “It just makes you want to curl up and hibernate.” Sadly, however, humans don’t have the same ability as hedgehogs and bears to snuggle down and go to sleep for the cold months.

The weather also has a huge affect on my keep-fit motivation. Going out on the bike makes me very chilly indeed (and I hate cycling into strong winds or through the rain.) I can usually persuade myself to get out for a short run every so often but it takes a huge amount of effort.

I don’t think I’m that different from most people. As soon as the winter arrives far too many exercisers hang up their running and walking trainers, or else put their bike away in the garage, and head indoors. While some might continue to train in the gym, many will give up entirely on keep-fit through the chillier months lured instead by a cosy-looking sofa and TV.

The excuses come as thick as heavy snow (I know them all!): it’s too cold, wet, icy and dark. But there are many good reasons to continue exercising through the chillier months. Just recently a twitter pal asked if I had any top tips so here are a few of the motivating forces that help me to keep-fit throughout the winter:

* A winter work-out can help to counter symptoms of SAD (seasonal affective disorder), the most common form of winter depression. Regular moderate exercise, especially outside in the natural daylight, helps to release essential endorphins that keep the traditional winter blues at bay.

* Cardio workouts that boost the metabolism are essential, too, if you want to avoid putting on weight during winter – as well as Christmas and New Year. You don’t need to go for a huge outdoors session as even just a brisk walk for 20 mins or a jog will keep your metabolism fired up. Why not find a way to walk 20 mins to walk? You could jump off the bus or train early or else leave the car further from your office.

* Staying active also has the added advantage of maintaining circulation – and keeping you warm for longer. A quick workout will soon have your heart working harder and sending the blood to your extremities, thus helping to keep you warmer and more comfortable even when you stop.

Make sure you warm up

A few words of caution though: Since muscles will be colder before starting exercise make sure you warm up slowly and effectively. I’d advise a five to 10-minute walk or a light jog before starting the actual exercise. Add in some dynamic stretches prior to you workout and some longer stretches after the workout, espeically on your calves, quadriceps and hamstrings.

Key to keeping fit through the winter is fun

In the summer there’s the advantage of sunshine and greenery when exercising outdoors. The light and warmth naturally makes us feel like being outside. But in the winter it’s dark and cold and unless the activity is fun who would bother?

So with that in mind, here’s a few winter fitness activities that will help to keep you in shape – and still smiling.

Running: Goals are vital for motivation, so set yourself the target of running Scotland’s first 10k of the year. The Lumphanan Detox 10k, near Aberdeen, usually takes place on January 2, a day when most Scots are off work and feeling unfit. If this is too close to Hogmanay celebrations then sign up for the BUPA Great Winter Run, a 5k race around Arthur’s Seat on January 8.

Cross country skiing: Cross country skiing, on longer thinner skis and with a pro-active poling action, is surprisingly aerobic and offers great leg, back and upper body toning, too. As the sport grows in Scotland, so does the range of trails, and some are even properly pisted after a snowfall. I enjoyed a fantastic trip to the Cairngorms to go cross country skiing earlier this year and hired skis in Aviemore. If you are new to the sport then hire a guide.

Roller skiing: But if the snow never comes, then the alternative snow-free version called roller skiing (utilising short skis on wheels) offers an equally challenging workout on tarmac. The first step is to take a lesson. Try Huntly Nordic Ski Club.

Dry slope skiing: Downhill skiing is a great muscle toner, calorie burner and spirits lifter. There are outdoor dry ski slopes across the country such as Midlothian Dry Slope, Glasgow Ski and Snowboard Centre and Bearsden Dry Ski Slope .

Downhill skiing: After last season’s fantastic snow dump in Scotland there are high hopes of the same again this year. Take advantage of one of five Scottish Ski Centres for a workout that is invigorating, cardio, toning and masses of fun. Skiing is ideal for al the family and a range of fitness levels. Take lessons if you’re a complete novice.

Outdoor swimming: According to Kate Rew, founder of the Outdoor Swimming Society, winter bathing offers a “fantastic endorphin and psychological buzz” as well as an “immune system and circulation booster”. But Rew warns people to follow tips on her website about how to acclimatise to Britain’s chilly waters. For those brave enough to try a brief dip, then head for one of two New Year’s Day Loony Dooks held at the Boat House Steps, South Queensferry, close to the Forth Bridges, and another in Broughty Ferry, near Dundee. For longer, but possibly no less freezing, swims check out Ye Amphibious Ancients Bathing Association, based in Broughty Ferry.

Surfing: Thanks to highly technical – and therefore, fairly cosy – 21st century wetsuits, surfing is now a year-round activity, even in Scottish waters. “What makes the winter even more attractive in this country for surfers is the more consistent waves,” says Sam Christopherson, of Coast2Coast Surf School, based at Belhaven, East Lothian. “For anyone willing to brave the elements over the next few months, there’s a lot of consistent surfing to be had.” Surfing is also one of the best adventure activities for both cardiovascular fitness and body buffing. A person weighing 10 stone will burn an estimated 600 calories during a three-hour session, and do some serious work to core muscles and upper body strength.

Ice climbing: While the indoor ice climbing room at the Ice Factor, Kinlochleven, is not strictly outdoors it does feel realistically cold. For novice climbers a taster session provides a thrilling and energetic introduction to this strenuous winter activity. The average person could burn a total of up to 800 calories ice climbing for an hour. “Most people are amazed by the cardiovascular and toning potential of ice climbing,” says Ice Factor owner and instructor Jamie Smith. “Scaling even just a small ice wall, using ice axes and crampons uses a wide range of your body’s muscles. Ice climbing is an excellent fun and a great way to get fit.”

Off-road walking and running: You’ll need to embrace the mud a little but walking and running on country trails and hills can be great fun and rewarding. Getting off the beaten track is more interesting than doing your usual pavement workout and the benefits of off-road walking and running include greater calorie burn, less chance of injury and better all-over-body toning. Check out Bagging Scotland for some great ideas for getting out and about this winter

Mountain biking: Numerous purpose-built centres offer trails to suit all abilities and if you invest in some winter fitness clothing there will be nothing to stop you giving this fun activity a blast.  See the 7stanes network, located across seven great centres in the Scottish Borders, check out the VisitScotland Active . Most centres hire bikes.

Skating: Roller skating on in-line blading offers a great cardio workout and is a fab toner for legs and bums. There is a vibrant skating community in Glasgow and across other areas of Scotland. The Try Skating group offers lessons and group skates and many parks and sea side boulevards

For a range of other ideas check out the VisitScotland Active site that I was commissioned to write.

* I will be reviewing some winter fitness kit in forthcoming blogs.