For years I had rehearsed a pre-scripted, Hollywood-worthy goodbye. But when that surreal evening arrived, my words were few: 'Goodbye, Dad. I promise not to live my life in vain.'

All of my proclamations through the years about changing my unhealthy lifestyle had been nothing but blather. I was a rotund 299 lbs at his funeral, but only when my father's suffering had ended did I realise the time for talk was over. I was, after all, gene positive. I had to do something drastic. I was heading the wrong way with my diet and exercise habits and the HD freight train was bearing down on another victim. I turned around and lowered my shoulder. I was terrified, yet determined to derail a genetic curse.

I began working out eighteen months ago, fatter than butter. I could only manage one minute of cardio. How on earth was I going to get in shape? I wanted to quit. But a small seed had been planted in my head when I was just a kid. It was the vivid memory of a 23-year-old athlete I saw on ABC's Wide World of Sports. Her name was Julie Moss, and she was leading the 1982 Ironman Triathlon Championship in Hawaii. For the uninitiated, Ironman is the world's most physically and psychologically gruelling one-day athletic event. It is the ultimate triathlon, combining a 2.4 mile swim and 112 mile bike race. Oh, and a full marathon (26.2 miles) after that. Julie Moss had led these 140.6 miles of misery all day. But near the end of the marathon course, she started to succumb to dehydration. She fell repeatedly during the last eight miles, somehow managing to stand up and run again every time. She went down again a hundred yards from the finish. Like a wounded animal, she continued crawling along the scorching pavement on her hands and knees. Hundreds of awe-struck spectators screamed at her to keep going. I was speechless as I watched from the comfort of our family room. With literally ten yards to go, she was passed by the woman who had chased her all day.

A second place finisher is usually forgotten, but Julie Moss' warrior spirit was imbued in me forever. Eighty-one pounds and half the body fat later, I'm crawling towards my own Ironman dream. Ancient injuries have resurfaced with a vengeance. Every day, newly discovered muscles are giving me their back-sass, like kids who sat in the back of class hoping they wouldn't get called on. One leg is three quarters of an inch shorter than the other, so I list portside like a sinking ship. I've got a foot specialist, a personal exercise physiologist, a chiropractor and masseuse putting me in the poorhouse.

But it's all going to be worth it. I participated in a longitudinal study at Indiana University School of Medicine in 1993, and in 2003 it was time for a ten-year follow-up. My contact with the dedicated research staff at IU could not have been timed better. What better way to battle HD than to raise awareness and create a special fund for research through my Ironman effort? The folks at IU eagerly accepted and I am already registered for the 2005 Lake Placid Ironman. I'm seeking public speaking opportunities to ask for contributions. I won't live in vain. I'm going to be an Ironman. Is there a better metaphor for people with HD and the people who care for them?

I only wish I had started sooner and I pray you won't make the same mistake. If you are already caring for a person with HD, thank you. But ask yourself: 'What am I doing to end HD? Do I have the luxury to wait for someone else to make a difference? Will it take the death of someone near me to serve as my wake-up call? Can I participate in a study? Can I donate some of my time or money to research programs like those at IU?'

I pray the tens of thousands in this fight will continue to demonstrate a will to win like Julie Moss. Let's all keep crawling these last hundred yards to our inevitable victory.

Jason Maier is a freelance writer from Buffalo, NY.