Fun ways to get fit; Dear Miriam.

Byline: MIRIAM STOPPARD

We all need to challenge ourselves sometimes and having a big event to work towards is a great motivator.

Getting fitter and raising money for a good cause at the same time is the best combination.

I completed a gruelling cycling challenge in the Middle East, covering up to 60 miles a day in the heat and wind. It was tough but the ride was for a wonderful charity so that's what kept me going.

Signing up to a sponsored event is a great incentive to get in shape - so why not pick an exercise and start training?

SWIMMING

The challenge:

The Great Swim - one-mile open water (outdoors) swim. London - August 15.

Strathclyde, Scotland - August 29.

Windermere - September 12 and 13. Suffolk - September 26.

You can swim on behalf of various charities, including Diabetes UK and Mind. Visit www.greatswim.org.

The benefits:

I love swimming and it's an excellent all-round exercise. Once I'd got my rhythm and breathing right, I found I could do 20 lengths without stopping.

It involves most of the major muscle groups and tones your stomach, thighs and arms. Regular swimming can help protect against heart disease and diabetes as well as keeping you slim.

In the water, you weigh one tenth of your body weight so it's low-impact on your muscles and joints, making it extremely safe.

My tips:

Try an open-water training session to get the feel for it. Visit www.outdoorswimmingsociety.com for locations.

Most pools offer lessons if you're a beginner or you want to improve. You can increase your speed significantly with a few tweaks to your technique.

Although front crawl is fastest, use the stroke that you feel most comfortable with. Boost your speed and stamina by including sprints during training.

RUNNING

The challenge:

Race for Life 5kms for Cancer Research UK - June/July in locations across the UK. Visit www.raceforlife.org.

The benefits:

Running is brilliant because you can do it any time, anywhere. It's hard to beat for cardiovascular fitness and burns more calories per half hour (around 300) than almost any other exercise.

Running reduces your risk of high blood pressure, heart attacks, stroke and obesity and improves your circulation. As a weight-bearing exercise, it will protect against osteoporosis. Devotees talk of the "runner's high" and most agree it's a great stress-buster.

My tips:

A quality pair of running shoes is vital. Get fitted by a specialist shop to prevent injury. For women, a sports bra is also essential.

I'd advise beginners to start with brisk walking before working up to a jog. Alternate between walking and running until you feel comfortable.

Try to run on grass or earth as softer surfaces are more forgiving on your joints. Include some hills in your training to increase stamina and to ensure you don't struggle on the day.

Cross training (doing other types of exercise such as cycling) will strengthen your leg muscles and help prevent injury.

WALKING

The challenge: Trek for Breakthrough Breast Cancer. Snowdonia - July 24-26, 21 miles. Cotswolds - August 14-16, 22 miles. Visit www.breakthrough.org.uk/uktreks.

The benefits:

Walking is my favourite form of exercise and I've even done some demanding trekking in the Himalayas - but I prefer the gentler, everyday sort. Even a short stroll has a positive effect on my mood. Just half an hour a day walking briskly can help ward off heart disease, diabetes and some cancers as well as boosting your energy levels. It strengthens your knees and hips, and increases bone density. Hillwalking or trekking increases your cardiovascular fitness even faster, as it's more rigorous.

My tips:

Get fitted for walking boots and socks at a specialist shop. Try Nordic walking poles to save your knees and help you balance. I rubbed cream into my feet every day before trekking and never got a blister. Try Atrixo. Why not join the Ramblers? They cater for all levels of fitness. Visit www.ramblers.org.uk.

CYCLING

The challenge: Bike ride for the British Heart Foundation Gower - July 5, 16 or 29 miles.

London to Southend - July 19, 59 miles.

Lancaster to York - Sept 5, 100 miles.

For more rides, visit www.bhf.org.uk/events.

The benefits:

Getting on your bike is one of the easiest ways to incorporate exercise into your life. It has less impact on your joints than running but can give similar health benefits.

To get really fit, I trained for nine months before my cycling challenge. A study for the Department of Transport found that even a small amount of cycling can lead to significant gains in fitness. Regular riding will tone your legs and bottom, and mountain biking or hill-training will work your upper body, too.

My tips:

Get to know your bike. Familiarise yourself with the gears and get used to handling it in any conditions. Use a female-friendly saddle or at least a pair of padded cycling shorts. I couldn't have done without them. Start out by biking short distances locally to get your confidence, then increase the mileage. For longer rides, you could join a cycling group.

IF YOU HAVE A CONDITION THAT MAY AFFECT YOUR ABILITY TO EXERCISE, SPEAK TO YOUR DOCTOR BEFORE YOU START TRAINING.

Additional research: LAURA FREWIN