By Jessica Hall

PHILADELPHIA (Reuters) - After spending the past few seasons running at lightning speed, sprint king Usain Bolt wants to spend some time in the slow lane.

With no Olympics or world championships this year, the Jamaican can ease off his assault on the record books.

"My aim is to stay on beat this year and do it with as (little) energy as possible," Bolt told a news conference on Friday.

"This year I'm kind of taking it easy. Next year I'll be working hard."

True to his word, Bolt will make a low-key start to 2010 by running at the University of Pennsylvania's Franklin Field in the Penn Relays on Saturday, the oldest U.S. athletics competition.

The 23-year-old, returning to Franklin Field for the first time since 2005, will anchor Jamaica's 4x100 meters relay team as part of the 'USA v The World' races.


Bolt, the world's fastest man, said the one thing he remembered most about competing at the Penn Relays as a teenager was the cold weather.

The forecast for Saturday's race is for a high of 65 degrees Fahrenheit (18 degrees Celsius).

The Penn Relays, which began in 1895, feature top high school and college athletes from the U.S. and around the world.

Bolt used to use the event as a warm-up for bigger races and said running in front of the large crowds helped his preparation.

Now, the competition does not play a major role in his training but still offers a chance to fine-tune his skills.

"It's not a very big part but it helps sharpen me up a little bit," Bolt said. "I'm feeling good in training, feeling better, feeling sharper."

While Bolt is not out to rewrite the record books on Saturday, he said training had not been all fun and games because he was due to face Asafa Powell.

Powell, his fellow countryman and former 100 meters world record holder, will compete in a second Jamaica team in the 'USA v The World' 4x100 relay.

"Our coach is taking this very seriously," Bolt said. "We've been working on baton changes and talking about if you drop the baton you'll probably get kicked out of the group."

(Editing by Tony Jimenez)