I've had this problem too, fatigue and pain on the bike and after. Post ride leg soreness and fatigue was bad. By accident I discovered my heel angle/placement made a big difference. As I think about it, I cannot remember exactly which way I went, brought the heel up or down. But by changing the heel position helped the post ride leg heaviness.

I now also use The Stick, Travel for my legs (popular with runners). Its easier for me than the foam because I can get more direct pressure on specific leg areas and its so much easier on my wrists. I'll use it if my legs begin to feel sore and heavy even if its the next day. I can feel the effects right away.