Can't get max value to be displayed!

This is driving me crazy!
I’m designing a UI to track the user’s hand speed. I need to get the maximum speed to be displayed on my interface. I’ve tried many methods but the script below is the closest I can get. This reading I’ve got is constantly changing and I just can’t get the max value to stay there. Any help?!

void Update ()

{
	//left hand
	
	initialL = LHand.transform.position;
	
	LHspeed = (initialL - currentL).magnitude / Time.deltaTime;
	
	
	currentL = initialL;

MaxSpdL = 0;
	
	if(LHspeed>MaxSpdL)
	{
		MaxSpdL = LHspeed;
		
}
	

}

Where do you declare the variable? Make sure that the declaration of your max value is a public int when and where you declare it!