What does it mean for muscles to tense up?

When muscles tense up, it means they're getting ready to work harder or protect something important.

Imagine your arm is like a spring, when you stretch it out and then pull it back, that’s tension. Now think of your muscles as those springs inside your body. When they tense up, they’re tightening, just like when you pull a spring tight before letting it go snap!.

Your muscles tense up all the time, like when you hug someone really tightly. Your arms and chest muscles get tighter so you can squeeze harder. That’s tension in action!

Or think of holding onto a swing while it swings back and forth. To stay on, your legs and arms need to tense up a little, just like when you’re trying not to fall off.

Tensing up is how muscles help you do things like:

• Lifting heavy toys
• Standing up after falling down
• Running really fast

So next time your muscles feel tight or sore, remember, they're just doing their job!