Exercise and Keep Fit Why Exercise? Dieting alone does not have a long lasting effect on weight reduction, unless complemented with regular physical exercise. Besides, exercise has a lot of other benefits. Exercise can help promote our physical and mental well-being. Regular exercise can improve heart and lung functions, reduce the risk of heart and related diseases, and control weight. It also improves muscle strength and suppleness, as well as joint and muscle flexibility. By exercising regularly, we feel better, work better and cope better with the stresses in life. Are You Ready To Start? Choose exercises that suit your age and ability Exercise regularly Exercise with friends or family members for fun and support Incorporate exercise into your daily activities e.g. brisk-walking, using the stairs, etc. Which Exercises Are For Me? I. Warm-up exercises These prepare your body for the vigorous exercise ahead Warm up for about 10 minutes before vigorous exercise, breathing naturally throughout the process Warm up exercises would include the head, back, tummy, the upper and lower limbs II. Cool-down exercises These help to prevent dizziness or fainting which may result from stopping vigorous exercise too suddenly Perform cool down exercises for about 10 minutes after vigorous exercise The exercises are the same as warm-up exercises except that the speed and range of movements should be gradually decreased III. Stretching exercises These help to keep your body supple and minimize strains and sprains to your joints, muscles and ligaments Points to note: * Ensure a correct starting position and stretch gradually to the greatest extent. When you feel resistance in the muscle being stretched, stay in that position for 10 to 15 seconds, then relax gradually * Avoid jerky movements * Breathe naturally during stretching * Repeat each movement 2 to 3 times * Do stretching exercises 3 to 7 times a week IV. Aerobic exercises These help to improve heart and lung functions and muscle fitness, and is effective in weight control Choose exercises that you really enjoy and suit your age and ability e.g. jogging, cycling, swimming, dancing and ball games The level of exercise can be measured by the heart rate during exercise The optimal level of exercise is determined by the ideal range of heart rate which is calculated as follows: * 2 ideal range of heart rate = ( 50% of maximum reserved heart rate + heart rate at rest ) to ( 85% of maximum reserved heart rate + heart rate at rest ) * maximum reserved heart rate = maximum heart rate - heart rate at rest * maximum heart rate = 220 - age * heart rate at rest can be measured after resting for 15 minutes For example : the heart rate at rest of a 17 years old boy is 70 beats per minute   * maximum heart rate = 220 - 17       = 203   * maximum reserved heart rate = 203 - 70       = 133   * ideal range of heart rate = (133 x 50 % + 70) = 137       to       = (133 x 85 % + 70) = 183           i.e. 137 to 183 beats per minute Physique varies between children. You may plan an exercise training programme for your child with reference to the following table: Training Programme Week Exercise Frequency (times per week) Level of Exercise (% of maximum reserved heart rate) Duration of exercise (minutes) Starting Stage 1 2 3 4 5 3 3 3 3 3 40-50 50 60 60-70 60-70 12 14 16 18 20 Training Stage 6-9 10-13 14-16 17-19 20-23 24-27 3-4 3-4 3-4 4-5 4-5 4-5 70-80 70-80 70-80 70-80 70-80 70-85 21 24 24 28 30 30 Maintenance Stage 28+ 3 70-85 30-45 V. Muscle-training exercises These help to increase muscle strength and endurance and do not require additional equipment for training Points to note : * Do the exercise series 3 times a week * Repeat each movement 10-25 times according to your physical ability. Do the whole movement of actions 3 times Home Exercise Programme I. Example of home exercise programme Every Monday, Wednesday, Friday 10 minutes warm-up exercises 20-30 minutes aerobic exercises (help to train heart and lung functions) 10 minutes cool-down exercises Every Tuesday, Thursday, Saturday 10 minutes stretching exercises 20 minutes muscle-training exercises Every Sunday 10 minutes warm-up exercises 20-30 minutes exercises for training balance, eye-hand coordination, quick response parents should encourage their child to participate in outdoor activities and non-competitive sports, such as dancing, skipping and cycling. This will prevent him/her from giving up too easily because of fear of failure. It would be better if parents also participate in these activities 10 minutes cool-down exercises II. Suggestions on physical fitness tests at home Here are two examples of simple fitness tests that can be carried out at home once every three months to check whether your home exercise programme is helpful in improving the physical fitness of your child. Stepping test (a) place a stable step (about 6 to 10 inches high) against the wall. Do as many steps as possible in 5 minutes (b) record the number of cycles that can be completed in 5 minutes. One cycle is : right foot up, left foot up, right foot down, left foot down; or left foot up, right foot up, left foot down, right foot down (c) the heart rate can be measured at the same time to estimate the level of exercise (d) to ensure safety, the step should be stable and placed against the wall. Choose a step with a height that suits your child's ability. Use steps of the same height for continuous assessment Sit-ups (a) lie on your back with your knees bent and arms crossed in front of your chest (b) ask somebody to stabilize your feet on the floor (c) starting from the lying position, lift up your body until your elbows touch your thighs, then return to the lying position. This is counted as one sit-up (d) lie back slowly with your back first. Do not bang your head on the floor (e) for children aged 6-12, record the number of sit-ups that can be done in 1 minute for children aged 13-18, record the number of sit-ups that can be done in 30 seconds The average number of sit-ups that can be done in Hong Kong children is as follows: No. of sit-ups in 1 minute Age Boy Girl 6 18 16 7 21 18 8 23 20 9 24 21 10 26 22 11 26 25 12 30 24 No. of sit-ups in 30 seconds Age Boy Girl 13 18 13 14 18 14 15 19 14 16 20 15 17 20 15 18 20 15 Sports Injury I. Common sports injuries in children abrasions and bruises heat stroke backache muscle cramps sprained joints strains in muscles and ligaments head injury II. Safety tips Consult your physician before sports training, especially if your child has a medical condition e.g. heart disease, asthma etc. Parents' or teachers' guidance during exercise is important to ensure safety Always warm up before doing exercise and cool down afterwards to lower the risk of strains and sprains Wear appropriate and comfortable clothes and well-padded shoes which support the heels and arches of your feet Take safety precautions e.g. wear helmets and knee protectors for cycling and life jackets for aquatic sports like canoeing, windsurfing etc. Do not exercise immediately after a full meal Beware of the weather and environmental conditions. Avoid doing vigorous exercises in extremely hot weather or high humidity Whatever exercise you choose to do, proceed gradually and exercise regularly according to your own ability. Never expect too much progress after just a few times Do not exercise when unwell or when suffering from an acute infection Stop exercising and take a rest if you feel breathless or dizzy, or if you have nausea or vomiting Do not perform dangerous movements which may harm yourself or others III. Management of sports injuries Keep calm when an accident has occurred. Inform parents or teachers immediately Parents and teachers should know some basic first-aid measures. They should also teach older children how to handle emergencies Manage the wound properly to prevent further injuries e.g. clean wounds with clean water and cover them with dressing or bandage etc. Seek medical attention whenever necessary Notes to Parents In order to have a good modelling effect on your child, you should actively participate in physical activities, and encourage your child to try various kinds of sports e.g. cycling, swimming, etc. Exercise with your child for fun and support Arrange outdoor activities for weekends or holidays e.g. hiking, picnicking, swimming Join extra-curricular activities with your child Share your child's feelings and give appropriate advice Energy Expenditure in Various Types of Physical Activities The unit for energy expenditure is kilocalorie or calorie Energy expenditure differs in different activities. (See table below) e.g. For a child weighing 45kg, 30 minutes of walking will bring about an energy expenditure of 0.162 kilocalories/min/kg x 30 minutes x 45kg = 219 kilocalories Type of Activity Energy expenditure/min/kg (kilocalories) Energy expended by a 45 kg child performing 30 minutes of this activity (kilocalories) Sitting 0.021 28 Knitting, Sewing 0.023 31 Playing cards 0.023 31 Standing 0.028 38 Writing 0.030 41 Playing piano 0.040 54 Playing violin 0.047 63 Canoeing 0.047 63 Housework 0.062 86 Gymnastics 0.064 86 Table-tennis 0.068 92 Walking 0.083 112 Bowling 0.094 127 Badminton 0.098 132 Tennis 0.109 147 Roller-skating 0.113 153 Freestyle swimming 0.128 173 Running on level ground (run round a football field 4 times, equivalent to 1.6 kilometres, in 11 minutes) 0.134 181 Basketball 0.138 186 Marching 0.143 193 Breaststroke swimming 0.162 219 Rope jumping 0.162 219 Running on level ground (run round a football field 4 times, equivalent to 1.6 kilometres, in 9 minutes) 0.194 262 Judo 0.196 265