weak legs

Hi!

I just wondered; I have been having weakness in my legs the last months (all tests taken- negative)..my thighs and knees feel stiff and weak, especially when I walk up a stair or do something "strenous". I am in bad shape (deconditioned and loss of muscles) compared to what I was before...could this be an important factor? Is the weakness a reslut of the "adrenaline overflow "over a long period? I am getting very tired of the tiredness....My legs will also start to ache and get tired after standing too long. Why is that so? I know claire weekes writes about this, and says its due to tension...but I don`t feel very tense in my legs...and its worse when I am active, and also when I ahve been inactive for a long time...