Can you train in MMA without competing?

MMA hasn't been around long enough for "long term detrimental effects" to really be documented. Getting knocked out a lot is bad for you, but we knew that long before modern MMA was a thing.

But to answer your question, yes, you can train for MMA and not compete. Probably 85-90% of people who go into MMA never compete for a living, though some might have a fight or two, or do a few grappling or striking (boxing, Muay Thai, etc) tournaments or matches.

Dude, when your in the cage your fighting for your life. I'm 15 and i went to become a legit mma fighter. But I'm no getting in the ring till i get into amazing shape and take a stand up fighting style and a ground fighing style. If you have no striking experience taekwondo does not count they will pumble you. Think about it this way Pro vs Rookie.

Of course!!! I know many people that train in mma that don't fight, typically you will spar in class, but there are many different types of martial arts, the only thing that pushes you to fighting is yourself :-) training is training. Both of my brothers, and myself have done mma, and my sister does crav... It's all a choice

About 99,9% of all MMA practitioners train and don't compete.

thats like asking if you want to own a motorcycle do you need to join a biker gang

it's called sparring

YES