Hi,
Thank you for that 
I thought single roll should be longer than i normally see but i didnt imagine it would take that long. What kind of foamrollers dio you use? I think i cant really hit glutes and hamstrings enough. i use this foamroller 
Ive seen people using baseball balls and simular. What do you think of that? I tried it with tennis ball but didnt like it.
Its funny how foam roller is becoming popular here. A group of sprinters at a track where I train just came up with some 5~10 foamrolles and other self-masage “devices”, using the before in between and after training every day
Iggy