Keeping Healthy: Diet, Exercise & the Body (Year 4–5) (Years 4–5) — Science

Find out how a good diet, exercise, sleep, cleanliness and water keep you well, and meet the busy work of your heart and lungs.

Your body is with you every day, so it is worth looking after. Keeping healthy is a happy mix of good food, moving about, rest, cleanliness and plenty of water.

Why this matters: Healthy habits you build now help your body grow strong and feel well. Small daily choices, like a walk or a glass of water, add up to a big difference.

Five ways to keep healthy

Habit	Why it helps
Balanced diet	Gives your body the right mix of food to grow, mend and get energy
Exercise	Makes your heart, lungs and muscles stronger
Sleep	Lets your body rest, grow and get ready for a new day
Cleanliness	Washing hands keeps away germs that make us poorly
Drinking water	Keeps every part of the body working well

The heart

Your heart is a muscle about the size of your fist that never rests. It pumps blood around your body, carrying oxygen and food to every part and taking away waste. Put your hand on your chest and feel it beating.

Try this: Feel your pulse sitting still, then do ten star jumps and feel it again. It beats faster because your busy muscles need more oxygen — that is exercise making your heart stronger.

The lungs

When you breathe in, air fills your two lungs. They take oxygen from the air into your blood, and let out waste carbon dioxide when you breathe out. The lungs gather oxygen; the heart pumps it everywhere.

Why water matters

More than half your body is water! You lose a little all the time through sweat, breathing and the toilet, so you need to top it up. Water helps your blood flow, keeps you cool, and helps every part of your body do its job.

On a hot day at the park you get thirsty quickly because you sweat to stay cool. Sipping water puts back what you have lost and stops you feeling tired.

The way heart, lungs and body work together without us even thinking is truly amazing.