Carmichael has been diagnosed with Chronic Fatigue Syndrome (CFS), a debilitating and complex disorder characterised by profound fatigue that is not improved by bed rest and that may be worsened by physical or mental activity. CFS affects more than one million people in the United States.

Carmichael's condition was more than likely brought on by his recent intense schedule of motorcycle and car racing, his training regime, and possibly a shortage of rest while caring for his newborn twins.

"I've just felt like I've been running out of steam the past few months. Training has been difficult. I've struggled to maintain my normal pace on my road bike and though I've been extremely tired, I've had a difficult time sleeping and never really feel rested," said Carmichael.

Unfortunately, RC's condition not only means that he'll miss this weekend's US Open in Vegas, but he also will not be able to attend the Bercy Supercross as planned. This essentially means that the seventeen-time champion's motorcycle racing career has come to a premature end.

"I'm disappointed to have it end in this manner," said Carmichael. "I was really looking forward to racing the Open and Bercy. Suzuki has stepped up the testing on the new fuel-injected RM-Z450 in order to premier it at the Open. I feel bad for Suzuki, my team and my sponsors as well as Live Nation, who have been a great supporter of me during my supercross career. As it turns out, MX des Nations was my last motorcycle race that came and went without the celebration with my team and close friends I was looking forward to."

"We are obviously disappointed to see Ricky's racing career with Makita Suzuki come to a end under these circumstances," added team manager, Roger DeCoster. "RC has been great asset for the sport of supercross and motocross and is a wonderful mentor for so many younger and older riders. His absence from racing will be greatly missed. Ricky will continue to contribute to team Makita Suzuki with testing and consulting but the important thing now is that he gets the rest and treatment he needs to get well."