Local teenagers are lagging far behind their counterparts in other developed Asian nations when it comes to physical activity, according to Lobo Louie Hung-tak. Dr Louie is an associate professor of the department of physical education at Hong Kong Baptist University. He said there was a lack of focus on physical education in Hong Kong. A study has found that local teenage boys were able to do fewer than four pull-ups on average compared to between eight and 10 pull-ups by youngsters in Japan, South Korea and Singapore, he said. With inactivity leading to rising obesity rates around the world, Dr Louie said those aged eight to 18 should focus on training their bodies to ensure lifelong health. Young Post agrees with Dr Louie. Exercise can help enhance your physical fitness and overall health. It boosts your immune system and prevents disease. But regular exercise is beyond the reach of many Hongkongers because of a lack of time, space and equipment. These simple exercises can be done using a sofa or chair at home - and you can even watch television while working out. Do each exercise 30 times or in three sets of 10. And don't forget to breathe properly while exercising. NOTE: Use a sturdy sofa or chair propped up against a wall. If your sofa is too soft, you might need to use a chair or the floor for some movements. 1 Arms and chest exercises a. Kneel facing your sofa/chair two feet away from the edge. Cross your ankles and put your hands shoulder-width apart on the seat's edge. This is your starting position. Slowly bend your arms, lowering your upper body until it touches the couch, before pressing back up. Repeat. b. Perch on the edge of a chair or sofa. Make sure your grip is strong. Move forward until your bottom is off the chair. This is your starting position. Bend your knees until they are at 90 degrees and dip yourself until your elbows are pointing behind you. Push back up to your starting position. Repeat. 2 Torso a. Lie down on your left side, on the couch or on the floor, and keep your legs together and knees bent. Hold the right side of your waist with your left arm and put your right hand on the back of your head so that your elbow points up. This is your starting position. Lifting your shoulder up, bring your left elbow towards your hips, squeezing the side of your torso, before returning to your starting position. Repeat and don't forget to work the other side. b. Lie on your back with your feet off the ground and your knees at 90 degrees. Lift your upper body off the ground and bring your elbows and knees as close together as possible. Repeat. 3 Legs a. Perch on the edge of your chair with your feet shoulder-width apart and hands at your side. This is your starting position. Stand up (without using your hands) while keeping your belly and back straight. Return to starting position but repeat just before your bottom touches the chair. b. Lie on your back with your palms facing down and under your bottom. Point your feet straight up with your legs together. This is your starting position. Slowly spread your legs as far as you can before returning to your starting position as slowly as possible. Repeat.