Charges to participate in a 10k, half-marathon, marathon, "fun run", walk, wheelchair race, bicycle race, triathlon, or any other similar non-motorized race are not considered to be charges for participation in games or amusement activities and are therefore not subject to tax.
Ga. Comp. R. & Regs. R. 560-12-2-.28
O.C.G.A. §§ 48-2-12, 48-8-2.