Duff Gonna Make You Sweat 'Til You Bleed

2/14/2008 1:22 PM PST BY TMZ STAFF
TMZ's photog got a killer workout while trying to get a shot of Hilary Duff yesterday -- sprinting four blocks to get a shot of the Duffster on Rodeo Drive.

Running to the adorable Duff sure beats doing those Jane Fonda lifts.