LONDON, Aug. 11 (Xinhua) -- Olympic and world champion Usain Bolt said on Tuesday he won't race again in 2010 because of tightness in his lower back.

Ricky Simms, the Jamaican's manager, said in an e-mail that the world record-holder at 100 and 200 meters will have treatment to loosen his back and then rest, skipping IAAF Diamond League track and field meets in Zurich on Aug. 19, and in Brussels on Aug. 27.

"It is better for me not to take any risks this year," Bolt said, according to Simms. "2011 and 2012 are very important ... and I hope to be back fully fit and healthy. I ... look forward to coming back stronger next year."

Usain Bolt of Jamaica reacts after he won the men's 100 meters at the IAAF Diamond League athletics meeting at the Stade de France Stadium in Saint-Denis, near Paris July 16, 2010.

Bolt lost to American Tyson Gay in the 100m on Friday at the DN Galan meet in Stockholm, and it was the first individual race he lost in two years. Gay ran 9.84 seconds, and Bolt finished in 9.97 - nearly 0.40 slower than his record for the 100m.

Simms said Bolt was examined Monday by a doctor in Munich who found the back problem.

"He has a tightness that restricts his ability to generate power in his stride and continuing to race in this condition could risk injury to his hamstrings or calf muscles," Simms wrote.

Simms said the decision to take time off was made "with a view to his future career."

He also said that an MRI exam showed that a previous left Achilles' tendon injury that caused Bolt to take time off earlier this year is healed.