Can you change the type of muscle fibers you currently have?

[FeelingLost]

People have two general types of skeletal muscle fibers: slow-twitch (type I) and fast-twitch (type II). Slow-twitch muscles help enable long-endurance feats such as distance running, while fast-twitch muscles fatigue faster but are used in powerful bursts of movements like sprinting.

I understand there are tests you can do in the gym to figure out what type you predominantly have.

My main hobby is mtn biking so when I go to the gym I try to do exersizes that will support that activity as well as general fitness.

In mtn biking I believe you need both type 1 and 2 twitch muscles.
Type 2 to get you up that steep section of the hill and type 1 because you are riding for 2-3 hours non-stop.

So if I am type 2 predominant can I do exersizes to increase my type 1 muscle fibers?
If so, I am assuming to do this it would be high reps low weighs vs low reps high weight?

 

[Vince]

I've always read about changing the type of muscle fibers you currently have. My understanding it's pretty hard, I would think there's some studies on it.

 

[FeelingLost]

I've always read about changing the type of muscle fibers you currently have. My understanding it's pretty hard, I would think there's some studies on it.

My research so far is saying the same Vince. You are born with a certain percentage of both and you can't really change that.
But could you exersize the one you have less of to help balance the ratio?
To optimize ones time in the gym should you determine what type of twitch muscles you have and that should define the types of exersizes you should do?