Can Jumping Make You Taller?

The story

Somebody may have told you that jumping on a trampoline makes you grow taller. It certainly feels true when you are up in the air. But your body does not work that way, and the real story of growing is stranger and better than the myth.

Here is what is actually happening inside you. Near the ends of your long bones, in your legs and arms, there are soft discs of springy cartilage called growth plates. They are little bone factories. Day after day they lay down fresh bone, and millimetre by millimetre, you rise. No amount of jumping, stretching or hanging from bars can hurry them along. Then, some time in your teenage years, the factories finish their work and close, gently and forever. After that, the height you have is the height you keep.

So what do the factories need? Three things, and you already know them. The first is food, because bone is built from what you eat. Protein builds the frame, and calcium, the mineral that makes milk and small fish and leafy greens so useful, hardens it like cement. The second is sleep, and this is the lovely secret of the whole story. Your body releases most of its growth hormone, the chemical messenger that tells the factories to build, while you are deep asleep at night. You truly do most of your growing in bed. When a grown-up says sleep helps you grow, that is not a trick to get you under the covers. It is simply true.

The third ingredient was handed to you before you were born. Your genes, the instruction book you inherited from your parents, decide most of the difference in height between one person and another. Tall parents tend to have tall children, and no food or exercise can rewrite that book. Which is why height is not a prize you can win. It was never a competition at all.

But measuring has its own fun. Measure yourself the moment you wake and again at bedtime, and you will find you are about a centimetre shorter at night. The soft cushions between the bones of your back get gently squeezed all day, then plump up again while you lie flat. Astronauts, floating with nothing squeezing them at all, come home from space a few centimetres taller, though gravity quietly takes it back within days.

And the trampoline? Keep bouncing. Jumping makes muscles stronger and bones tougher and hearts healthier, which are far better gifts than a centimetre. It just will not make you taller.

So eat well, play hard, and sleep deep, and let the little factories do their patient work. Then stand however tall you stand, because the best things about you were never going to be measured with a ruler anyway.