Former U.S. Senator John Danforth may think he has a spectacular makeover plan in the works for the Gateway Arch grounds. To runners, however, the overtures ring blasphemous. Cafés? Hot-dog stands? As well it should take an act of Congress to hoist commercial property on our fat-ass of a town's best place to jog! This is sacred turf, all right. Sacred turf for happy feet. For those who haven't set foot downtown this century, a quick review: The Arch grounds are sprawling, verdant, dotted with water fountains. There ain't a homeless dude in sight (usually). They're clean and shaded — but well-lighted. Weekend mornings and evenings, the Arch grounds are uncannily peaceful. Last but not least, you have the 64 broad steps to the riverfront. That's prime real estate for gluteal plyometrics! Put another way: the place to slash a few pounds off ye ol' statesman butt.