I do an exercise -isometric- where I stand erect and lift a leg as high as I can for as long as I can and then alternate to the other. Also keeping both straight I lift one foot up behind me as high and as long as I can. That one always ends in cramps lol. With the first I'm up to 40 seconds now, only do it 4 or 5 times a week, usually when I'm just standing around doing nothing. It's improved my comfort on the bike a lot! I can go an hour or more and get off feeling normal, a far cry from before where i'd be limping for a minute afterwards.