DES MOINES, Iowa (AP) — Tyson Gay ran a bit scared at U.S. championships.

Not from the competition, but what awaited him at the end of the track — a cushioned mat to keep him from running into a wall.

USA Track and Field figured it had found a wind-win situation for the strong breezes inside Drake Stadium— change the direction for all sprint events starting Friday.

But the decision met with some mixed reviews. Some runners didn't mind the fact that instead of bursting from the blocks in the north end of the stadium and finishing in the south, it was reversed. Some were a little confused.

Gay breezed down the line in 9.75 second to win the 100 over Justin Gatlin and then had to abruptly start tapping the brakes. The protective mat was about 26 yards or so from the finish line.

"It was just the whole mat thing in your mind," Gay said. "Indoors, you run into a mat. You're running a lot faster outdoors, running into a mat. It was a little bit scary."

The times were definitely faster on Friday, though. Gay certainly displayed that as he finished with the fastest time in the world this season.

That's quite a contrast from the day before when sprinters fought a strong breeze all the way to the finish. Dentarius Locke of Florida State had with the top time on Thursday, a pedestrian 10.19 that wasn't even among the top 50 times in the world this season.

Had it been her decision, hurdler Dawn Harper would've chosen to compete in the same direction as always. The 2008 Olympic champion much prefers going over the hurdles with the wind in her face than at her back.

"A tail wind can push you into the hurdles a little bit, (so you) clip the hurdle," explained Harper, who won her heat. "Walking down (on the track), I was like, 'You have to be kidding me about this wind.' It was crazy. Getting into the blocks, you didn't feel it as much. Once I clipped the first hurdle, I was like, 'OK, there's some wind.'"

A Des Moines native, hurdler Lolo Jones has been racing on this track for years. The direction switch threw her off a bit.

"Weird, because I did all my visualizations the other way," said Jones, who had the fastest time in her heat, much to the delight of the hometown crowd. "To turn it around was kind of crazy."