You are so right! I never thought about it, but yes, for sure the muscles keep tensing up and so it makes good sense to stretch several times a day. I now undersand why I get up so much in the night - because I realised I could get bac to sleep quicker afterwards, but now I understand it is because I have stretched my legs when I get up! Thanks Sheila, great insight! And yes, also true, cannot hold one position for too long.