Most of us know the benefits of exercise. It keeps you healthy and strong and does its share to ward off the effects of ageing.

Now take that knowledge and stand it on its head. Chances are, you will be doing even more to keep Father Time at bay.

I am talking about upside-down yoga, where exponents spend the better part of their workout with their bodies in an inverted position.

Paula Weisman, 32, is one such person. The instructor at Pure Yoga enjoys the rush of blood to her head so much that she teaches an hour-long class of upside-down yoga every Tuesday at 6.15pm.

The American, who has been doing yoga for a decade, was certified as a yoga instructor in New York and moved to Singapore two years ago.

While demonstrating some of the upside-down poses and encouraging me to try them too - okay, I did only the easy ones - she explained that most people who attend her class are initially apprehensive about their balancing abilities.

'But once they manage their first headstand, they get more confident,' she said. 'In fact, they even find it exhilarating after that.'

She quoted Indian yoga guru B.K.S. Iyengar, who founded Iyengar Yoga, when explaining the anti-ageing benefits of inversion poses. He called people who do headstands 'fountains of energy'.

Now, before you rush off and try standing on your head, here are a few words of caution from Weisman:

Don't hold any of the inverted poses for more than two minutes at a stretch because they make the blood rush to your head and increase the pressure on the blood vessels there.

When you complete each pose, go into the baby pose (on your knees, with head almost touching the floor) for a few seconds to let the body get back to equilibrium.

People with high blood pressure, heart problems, detached retinas, neck injuries or ear problems, and women who are pregnant, should not attempt this.

Dr Patrick Goh, consultant sports physician at SportsMed Central in Gleneagles Hospital, said inversion poses like headstands are fine for healthy people as long as they are done for short periods of time.

This is to ensure not too much pressure builds up in the blood vessels in the brain.

He does not buy the anti-ageing claims, however.

'I haven't seen any scientific evidence that proves one stays younger by forcing more blood to the head,' he said.

pradeep@sph.com.sg

RIGHT ANGLE POSE
Beginner's level

RIGHT ANGLE POSE

Lie down with your right hip and right shoulder touching the wall. Then slowly lift your legs along the wall as you swivel your upper body away from it.

When your body is perpendicular to the wall and your buttocks in contact with it, lie back and keep the legs up.

LEGS UP THE WALL
Intermediate level

LEGS UP THE WALL

This requires some arm strength, so make sure you have a soft surface under you in case you collapse. Sit with your back to the wall and mark the spot where your heels touch the floor. Then get on all fours, feet touching the wall and palms at the marked spot, and slowly walk your legs up the wall till your body is bent 90 degrees at the waist.

End the pose by slowly "walking" down instead of dropping your feet to the floor.

SHOULDER STAND AT THE WALL
Advanced level

SHOULDER STAND AT THE WALL

This requires balance but you can do it with the wall for support. Start from the Right Angle Pose and slowly walk your legs up the wall as you support your back with your hands. When your legs are all the way up, slowly move one leg away from the wall.

Once you have got your balance, try and move the other leg away too. End the pose by slowly bringing your feet back the wall and 'walking' down.