Exercise intolerance is when someone has trouble doing physical activity or exercise. It can happen for all kinds of reasons and it means that the body has a harder time using its energy to move and work-out.
Picture this: Imagine you are playing soccer with your friends outside. Your body needs a lot of energy to run, jump, and kick the ball. But when someone has exercise intolerance, their body might not be able to provide enough energy to do all those things. It's kind of like trying to run a race with a backpack full of rocks on your back.
There are many things that can cause exercise intolerance like being sick, being out of shape, having a health condition, or even just feeling tired. It's important to talk to a doctor if you think you might have exercise intolerance so they can figure out the best way to help you. They might suggest exercises to help build up your strength slowly or give you medicine to help you feel better while you're exercising.
Remember, exercise is important for keeping your body healthy, but it's okay to take things slow and work your way up to more activity!