Indices of good health: exercise, sleep and check-ups

1Why this matters

The World Health Organization's constitution, adopted in 1946, defines health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity". So a student who is not ill, but who is always tired, sleeps five hours a night and never moves except to sit in class, is not in good health.

An index (plural indices) of good health is a sign or a habit that tells you how healthy a person is. In this lesson you will learn to recognise the signs of good health and the five habits that produce it: hygiene, exercise, sleep, medical check-ups and a balanced diet.

2Signs of good health

A healthy young person usually:

• has enough energy for lessons, chores and play;
• grows steadily in height and weight for their age;
• has clear skin, bright eyes, pink gums and strong teeth;
• has a good appetite and passes stools regularly and comfortably;
• falls asleep easily and wakes up refreshed;
• can concentrate, gets on with other people, and recovers quickly from small illnesses.

3The five habits behind good health

1. Hygiene. Keeping the body and clothes clean, as in the last lesson.

2. Exercise. WHO guidelines (2020) say that children and young people aged 5 to 17 should do at least 60 minutes a day, on average, of moderate-to-vigorous physical activity. On at least 3 days a week this should include vigorous activity and activities that strengthen the muscles and bones. They should also limit the time they spend sitting, especially in front of a screen for fun.

• Moderate activity makes you breathe faster, but you can still talk: a brisk walk to school, cycling on flat ground, sweeping the yard.
• Vigorous activity makes you breathe hard, so you can only say a few words: running, football, fast dancing, skipping.
• Muscle- and bone-strengthening activity makes the body work against a load or jump: carrying water, climbing, press-ups, jumping games.

Regular exercise strengthens the heart, lungs, muscles and bones, helps keep a healthy weight, and improves sleep, mood and concentration. Warm up first, drink water, and do not exercise hard when you have a fever.

3. Sleep. Sleep is when the body grows, repairs itself and fixes the day's learning into memory. The US National Sleep Foundation (2015) recommends 9 to 11 hours a night for children aged 6 to 13, and 8 to 10 hours for teenagers aged 14 to 17. Habits that help:

• go to bed and wake up at the same times every day, weekends included;
• switch off phones and screens about an hour before bed;
• sleep in a dark, quiet room, under a mosquito net;
• avoid tea, coffee and energy drinks in the evening, because the caffeine in them keeps you awake.

4. Medical check-ups. A check-up finds problems early, before they cause pain or harm: poor eyesight that makes the board look blurred, tooth decay, anaemia, or high blood pressure. Check-ups are also the time to keep vaccinations up to date. In Rwanda, schools help with deworming and with vaccinations such as the HPV vaccine for girls; community health workers in each village and the health centre are the first places to go; and community-based health insurance (Mutuelle de Santé) helps families pay for care. Go to the health centre without delay for a fever, a cough lasting more than two weeks, or any sudden change you are worried about.

5. A balanced diet. Eating a variety of foods from all the food groups every day, in the right amounts. You will study nutrients in detail later in this course.

Worked example: checking a week of activity and sleep

Ishimwe is 14. In a normal week he walks briskly to school and back, 25 minutes each way, on 5 days. He has one PE lesson of 40 minutes and plays football for 90 minutes on Saturday. He goes to bed at 22:45 and gets up at 5:15.

Step 1: activity for the week. Walking: 25 × 2 × 5 = 250 minutes. Total: 250 + 40 + 90 = 380 minutes.

Step 2: compare with the guideline. 60 minutes a day for 7 days is 60 × 7 = 420 minutes. He is 420 − 380 = 40 minutes short. His vigorous activity (PE and football) happens on only 2 days, not 3.

Step 3: sleep. From 22:45 to 5:15 is 6 hours 30 minutes. At 14 he needs 8 to 10 hours, so he is at least 1 hour 30 minutes short.

Step 4: a plan. Skipping or running for 20 minutes on two evenings adds 40 minutes of vigorous activity, which brings him to 420 minutes and to 4 vigorous days. Going to bed at 21:15, with his phone off from about 20:15, gives him 8 hours.

Practice

Solution. Any four of: plenty of energy, steady growth, clear skin, bright eyes, healthy pink gums, good appetite, good concentration, wakes up refreshed, gets on well with others.

Solution. Running: 3 × 30 = 90 minutes. Walking: 7 × 20 = 140 minutes. Total 230 minutes, against 420 minutes needed. That is about 33 minutes a day, so he does not meet it; he needs 190 more minutes a week.

Solution. Some problems, such as poor eyesight, early tooth decay, anaemia or high blood pressure, give no clear signs at first. A check-up finds them early, when they are easier and cheaper to treat, and keeps vaccinations up to date.

Solution. The screen in bed and the evening coffee (caffeine) both keep him awake. He should do homework earlier, drink water or milk in the evening, switch the phone off an hour before a fixed bedtime, and aim for 8 to 10 hours of sleep.