Pebbles in one or both shoes, plus a thick insole, and some sort of tourniquet on a leg just loose to allow blood to flow will be sufficient to trick these for sometime so long as one can carefully conceal any other uniquely identifying factors.
The system needs to be right one time only. You cannot afford to make a mistake and odds are stacked against you. You cannot do that unless you are wanted for xx years of jail, otherwise it's too big of a burden...day after day.
Plus, they'll know by your smartphone (pay, map++ apps) where you are. Merge the data and there you go.