(Oct 21) ARE you thinking of getting more exercise? Not sure what hobby or activity to take up?

There are many sports and hobbies out there that will give you a good work out - cycling, swimming, martial arts, wakeboarding - but for a start, here's a quick guide.

Running versus aerobics

Calories burnt: Both activities will give you a good cardio workout. You will burn 612 calories per hour for running, if you can run 1km in 6 minutes. Aerobics burns 374 calories per hour.

How long before you see results: If you run three times or more a week, you'll see changes after three weeks. However, you need at least a month of aerobic classes to feel the difference.

Benefits: Running strengthens and tones all the lower limb and buttock muscles and the swinging of the arms means that your spine is gently rotated.

A good aerobics class will challenge both mind and body and improve strength and coordination.

There is also a greater chance that you will get more of an upper body workout in aerobics, especially if light dumbbells are involved.

And with any group activity, making new friends is a good psychological boost. Running tends to be a solitary pursuit.

Risks: Good shoes are essential in running as your feet absorb three to four times your body weight every time they hit the ground. Regular runners will need to get new shoes every year or so.

But is running bad for your knees? Apparently not.

A study by Stanford University showed that adults who run regularly (at least 6 hours a week) are less likely to have joint pain when they get older, compared with inactive people.

The theory is that if you run consistently, your body gets used to the impact and copes. Irregular joggers are at greater risk of damaging their muscles and tendons.

Add zing to your morning run by changing the terrain or route to challenge yourself.

Low-impact aerobics classes, where one foot is in contact with the floor the whole time, are preferable to high-impact ones.

Supportive shoes are also a must. Fight against boredom by joining a variety of classes like body combat or pump.

Yoga versus pilates

Calories burnt: 102 per hour for a general class, but power yoga can burn up around 245 calories per hour. Pilates burns between 170-230 calories per hour.

How long before you see results: You will definitely feel a change after doing yoga for eight weeks, twice a week. For a speedier effect, Pilates will produce results after six weeks.

Benefits: Yoga is famed for establishing unity between body and mind, and you will leave a class feeling centred and calm.

The different poses also stretch various muscles and massage the abdominal organs.

The American Council on Exercise found that women who attended twice-weekly yoga classes for two months had a 13 per cent improvement in their flexibility and physical strength.

Pilates was first used by dancers and athletes to develop their postural awareness and core strength. Improved stability of these core muscles helps to prevent the incidence of back pain in everyday life.

Risks: While gentle yoga is good for back pain, 'stronger' yoga like power yoga or ashtanga, coupled with poorly-trained instructors, is liable to make your back pain worse.

Be mindful of your own body and stretch to your own limits, you don't have to attain the picture-perfect pose to get the benefits.

But if you want the body of a movie star, you will need to supplement your exercise routine with running or aerobics.

Another study from the American Council on Exercise found that an advanced pilates class raised heart rates to just 62 per cent (experts recommend 64 to 94 per cent to get a good cardiovascular workout) and is the equivalent to a slow walk.