Why do I have trouble sleeping after exercise?

You may have trouble sleeping after exercise, because your body is super excited. You need some time to calm down and put the blood pressure, heart beat etc to a normal condition.

Your body needs to calm down and your muscles need you relax before your brain can actually rest into a sleep.

Because when you get pumped up from exercise, it makes you more awake and happy.

Exercising boosts your adrenaline and endorphins, which can keep you feeling "up" long after you've stopped. I know fitness experts recommend leaving at least two hours from when you stop exercising to the time you need to be in bed.

your blood is pumping and your heart rate and blood pressure go up, try doing some yoga or listening to relaxing music afterward

It's possible that you're having trouble sleeping after you exercise because your body isn't used to being so active. Your heart has to pump harder and more often than usual, and your body has to try and readjust to find some kind of balance with the activity. So it's likely that you might just need to do some calming exercises, like mindfulness or yoga nidra, to try to naturally calm your mind/body down. Your mind and your body are very often correlated, so if your brain starts to calm down, your body will naturally follow suit, or vice versa.

After exercise your body is pumping with energy and in turn it becomes harder to sleep, it's hard to calm yourself after exercising. Maybe try exercising in the morning or early after noon.

Exercise is great, but it also gets your heart rate up and your body ready for more activity. Therefore, sleeping right after exercise can be difficult.

Simply put, it's most likely because cortisol significantly increases after exercise (especially after heavy/intensive exercise). Cortisol is associated with anxiety and wakefulness. My tip is to not intensively exercise too close to sleep and/or to only do some light exercise before your desired bed time.

I have the same problem, my doctor said it was probably because your brain and body needs time to calm down, try waiting until the afternoon to exercise, then eat your dinner or shower, and then sleep. Those kinds of things can help your mind and body calm down.