File :-(, x, )
Anonymous
Question about a strange feeling I get when I flex my muscles

When I flex my bicep to its max or my calf, I get a feeling like my muscle is knotted up or it's going to tear if I flex any harder, what is that?
it's painful, and would be more painful if I pushed any harder. it also seems to go away after I work out and come back after a while.

pic related
>> Anonymous
The pump hurts, yet it feels good man
>> Anonymous
     File :-(, x)
>> Anonymous
it feels like someone is blowing air into your mussels jaaaa