Connecting one sphere to another (like pressing "e")

Hi, I am making a stickman model, and basically joints are spheres (knees, elbows, pelvis, etc…) Now I want to know how to make a cylinder around 2 spheres, I want to select a ring of each sphere and then basically connect one sphere’s ring to another, any tips?
Thanks in advance

Both spheres must be part of the same object
Select both edge loops and W / Bridge Edge Loops or enable the ‘Loop Tools’ addon in User Preferences / Addons and use its Bridge function.

Thanks alot ;), expecially for the fast anwser, and in the title I meant “f” not “e” :stuck_out_tongue: