This time I started in pain.

I'd had back spasms, a sore IT band and an achy hip. In fact, my sisters and I had a great time laughing at all the rolling, icing, taping and massaging I had to go through just to be capable of walking up to the start corrals of the Las Vegas Marathon last Sunday.

Pain is an interesting companion.

Everybody, it seems, has some pain. A headache, a backache, a sore shoulder, a sore knee — something, somewhere is throbbing most of the time.

For some of us, pain has been in and out of our lives as long as we can remember. For others, it is a by-product of aging or injuries.

Anyone who has played competitive sports understands that pain is not always the enemy it seems to be. Sometimes it's what reveals to us how strong we actually are and how much we are capable of accomplishing. Other times, it is, indeed, the thief of our dreams.

The reason I love to examine pain — especially physical pain — is that it is so relative. An injury that sidelines Person A doesn't even faze Person B. Why? Does this mean anything? Is one smarter than the other? Is one tougher than the other? Does it depend on what's on the line?

I mean, sometimes you don't need to suffer.

And then there are marathons.

Suffering is mandatory. It's not just inevitable, it is something most repeat marathon runners embrace.

I am not there yet. This was my eighth marathon, and while I love running these races, I am not quite loving how much it hurts to run 26.2 miles.

So I cheat a little.

I find it easier to endure pain for a reason. I can stumble along farther and faster with a little inspiration.

Maybe it's my mother's influence, but suffering for someone else is so much more appealing than struggling for me.

My youngest sister, Dani, who knows I usually write down my reason and carry it with me, asked me the night before the race who I was running for this time.

"Daphne," I said. "If she can shove her skinny, crooked little body into that unforgiving, plastic cast every day, I can deal with the few aches and pains that come with running."

Daphne Claire is a 10-year-old unlike any other I have met. She was diagnosed with scoliosis two years ago. About a month ago, the doctors told her the curve of her spine was bad enough that she needed to wear a brace.

Her reaction?

"Yeah! When can I have it?" she gushed.

Everyone's reaction was the same — surprise and then skepticism.

"That will wear off after a couple of weeks."

"She doesn't realize what that is."

"Once people make fun of her, she won't be so excited."

She'd excitedly tell someone about her great news, only to be pitied or consoled. She didn't get it. I didn't want to hear it.

So I joined her happy train and watched as she turned visits to the doctors into play dates full of giggling anticipation.

Her "I'm-so-excited" began to be my joy. I was actually happy for her.

"This is so awesome," she said the first day I let her wear it to school.

"Yes, my love, it is," I said. "You are a lucky, lucky girl."

"I know," she beamed. "I'm so lucky."

And she's so tough.

The brace was almost immediately the source of pain. It rubbed her ribs until they were red and raw. It cut into her hips. Sometimes she'd cry, but she refused to take it off.

"It's going to make my back straight," she said. "I can do this."

Yes, she can. This is the same little girl who had open-heart surgery when she was 11 months old. She still has a leaky valve that someday must be replaced.

This is the same kid who wears mouth gear that will slowly spread her teeth apart so there will be room for all her permanent teeth.

Everyday she is in pain.

So what does she do about it? She plays. She goes to dance, karate, trumpet lessons, and the day before I hobbled up to the Las Vegas start line, she ran a 5K all by herself.

She braved the cold temperatures (three pairs of sweats) and went to the Nick Yengich Memorial run in Copperton, a run that honors the late brother of attorney Ron Yengich and raised money for ALS, as well as the Utah Food Bank and Toys for Tots.

Usually someone from our family runs with her. This year, no one was available so she did it alone.

"I cried a little at the beginning," she said to me after the race. "I was just scared. But I did it."

And if she could run in the cold all by herself, I could run the marathon with a little discomfort.

When I started to feel like quitting — and yes, I always have a moment or two where I question my sanity — I thought of her. I thought of her joy; I thought of her courage; and I thought of how she never lets pain stop her from doing what she wants to do.

Not only did she do it, she loved it.

So I started to tell myself how much I loved this race. I loved the endless asphalt. I loved the crazy things you never see anywhere but in Vegas — like the Bengal tiger, Elvis running a marathon, a run-through wedding chapel, and a lot of provocative cards littering the streets. I loved the young girls who came out in their cheerleading gear to urge us on. I loved all the other runners who offer you whatever they have during a marathon because they understand your suffering. I loved the volunteers who didn't get a medal for standing in the cold wind for six or seven hours so we crazy people could torture ourselves. I loved my sisters for coming with me and making me laugh so hard I thought about wearing a Depends diaper. I loved the pain because it was, after all, part of what I was trying to conquer on this race course.

Pretty soon I was running a little faster and eventually with a little less pain. No kidding. When I finished, I felt better than when I started.

That's not to say the pain didn't come back. The knees got tight and stairs began to look like the impossible obstacle.

Pain will always come back. It will always be there, lurking, waiting to spoil our fun if we let it.

What I've learned from Daphne is that giving up because of the pain is optional. It might change us, it might slow us down, it might even alter our course. But it will not stop us from boarding the happy train.