Originally Posted by
Aged Bike Fixer
SS/FG does not mean "one gear" it means one gear ratio (with or without a freewheel).
There is a gear in the front (the chain ring) and one on the rear wheel (the cog).
Why try to confuse him/her?
EDIT: also, not necessarily most fitness potential on fixed, I rode singlespeed today and discovered how off my pedal stroke was. Fixed tricks you into thinking you are being super efficient.