Rachel Taylor has numbness in her left arm, and reduced mobility in her left leg. Yet she does not look or act like someone suffering from a chronic illness. Tall and lean with dark hair cropped in a sporty cut, she has a broad smile and laughs easily, but her voice softens when she speaks of Multiple sclerosis. "I often have survivor's guilt because there are so many with MS that aren't so lucky."

Taylor, 54, discovered that she had MS twelve years ago. While on an overseas trip, she experienced dimming eyesight in her left eye. Taylor was already familiar with the symptoms of MS because, oddly enough, she and her husband Pete had participated in a bike tour for the disease several times. In fact, Pete, who owned a sporting goods store at the time, was recruited to organize the first Utah tour in 1986, now called Utah Bike MS.

After returning home from their trip, a formal diagnosis confirmed her fears. "I just remember pacing around my yard filled with terror because I didn't know what direction my life was going to take," she recalled.

Now with a new perspective, Taylor, an ambassador for the National Multiple Sclerosis Society, joins 2,500 others every June in Cache Valley for an up to two-day, 175 mile bike ride. The largest fundraiser for the Utah chapter, the event raised $1.1 Million for MS research and support for patients this year.

Affecting one in 300, Utah has one of he highest incidence rates of MS in the country. The disease arises when the body's immune system attacks its own central nervous system, the brain and spinal cord. The most common sites of damage are myelin, an insulating layer that coats nerve fibers, and the nerves themselves. As a result, nerve impulses are crippled or blocked, producing variable symptoms including tingling, numbness, pain, and paralysis in different parts of the body. In early stages of MS, about 85% of people experience attacks intermittently, while the minority undergoes a steady worsening of the disease.

"Many patients do quite well, and can continue working at their jobs and participate in a bikeathon. Others accumulate physical disabilities over time and may end up in a wheelchair," said John Rose, M.D., an MS specialist and professor of neurology at the University of Utah. He noted that what is often most difficult for new patients is the unpredictability of the illness.

MS results from multiple causes which may help explain why the disease's course can vary widely between individuals. Though the causes are still unknown, there are clues that will help researchers to one day determine what they are. Women with MS outnumber men nearly 3 to 1. It is most prevalent in people of northern European descent, and is more common in northern locales far from the equator. "There are clearly environmental factors involved," said Rose. "Susceptibility to MS is also due to numerous genetic factors."

With so many different factors at play, MS can be a difficult illness to treat. Today, there are eight FDA approved drugs that can slow or stop the onset of new symptoms. One patient may respond best to drug A, and another to drug B, or to a combination, but there are many with MS for whom currently available drug therapies are ineffective. Money raised through Utah Bike MS directly funds research toward new therapies for alleviating MS.

Ironically taking part in the ride, or in any rigorous exercise, can cause MS symptoms to flare. Ambient heat, exercise, and stress raises core body temperature, slowing conduction in nerves that are already impaired. An added complication is that MS patients fatigue more easily.

For these reasons, those with MS were advised to abstain from exercise as recently as twenty years ago. Since then, Andrea White, Ph.D., FACSM, research associate professor of exercise and sport science at the University of Utah, and others have shown that in exchange for a transient worsening of symptoms during workouts, patients became physically fit, stronger, happier and more proactive.

"Athletes with MS are like elite athletes," said White. "Think of professional cyclist Lance Armstrong, who goes faster and harder even though he is already tired from training. They train themselves to cope with it."

Strong headwinds and searing heat made this year's Utah Bike MS particularly brutal. "I'm in the best physical shape of my life this year and yet that 95 degree heat temporarily wipes it all away," remarked Taylor. She overcame these difficulties to finish her first century ride.

Taylor's motivation for riding Utah Bike MS has changed from 26 years ago. "Before my diagnosis, biking the tour was about physical achievement. Now it's spiritual, physical, emotional - the works."