Sometimes the struggles we choose can unite us with those whose suffering comes unbidden.

At about mile 22 I practically forgot the reason I was running-or at this point barely jogging-my second marathon in as many years. My feet were screaming at me to stop "offering it up" and lay my aching body down in the grass. It would feel so good to stretch out and soak up the Florida sunshine. A little voice asked, "Couldn't praying a rosary in the prone position be just as effective as pounding out 26.2 miles?"

The answer: not today. I had prayed many rosaries for Joseph, my great-nephew, since he was diagnosed with leukemia for the second time in his 11 years. That morning though, I was wrapping up several months of physical and emotional challenges as part of a different kind of prayer on his behalf. Despite my throbbing muscles, or even because of them, I continued to offer up the pain for him and others with this terrible blood cancer. I gritted my teeth, turned up my music player, and stumbled toward the finish line.

In my near-delirium during those last miles, I could almost hear a sweet Irish accent encouraging my schoolmates and me to "offer it up" when we had a headache or skinned knee many years ago. I do not remember a clear explanation of the concept. Maybe the sisters' intent was for me to feel there was a reason for pain, or that practicing this discipline could help me overcome my helplessness when things were bad. I forgot about this type of prayer for decades until I decided to train for and run marathons for a purpose beyond fitness.

Unfortunately, over Christian history some have presented "offering it up" as a way for the poor and suffering, even those in abusive relationships, to accept their lot in life as an expression of God's will. This unhealthy view forgets that, though suffering is a part of life, God offers us help in overcoming it. Christ indeed teaches us to take up our cross, follow him, and rely on his help in working through challenges. So while we may "offer up" our pain through difficult times, we should also offer up the prayer and work involved in overcoming them with God's help.

Where did the Catholic practice of offering up suffering for a cause come from? The Bible is full of sacrifices for others, with Jesus' death for our salvation as the greatest example. St. Paul teaches us in several of his letters the usefulness of putting up with pain for our own good and the good of others.

Many of my favorite saints have offered themselves up: St. Faustina of the Divine Mercy devotion, Thérèse of Lisieux through her Little Way, and Padre Pio are some of the more recent examples. I admire them as heroes of the "church militant" during their lives on earth who are now part of the "church triumphant" praying for us in heaven.

I made a personal decision to offer my time and effort for Joseph. A popular T-shirt worn by runners during marathons is, "If you think 26.2 miles is hard, try chemo." That says it all.

The first time he had leukemia, Joseph was 2 years old. He fought it off after a couple of years of treatment, and the doctors told us, reassuringly, that the odds of this terrible disease reoccurring were about 1 percent. Unfortunately, that long-shot chance was all the cancer needed to sneak back into his life before he began fifth grade.

When I heard Joseph was sick again, I knew I had to do something. I prayed, visited him in the hospital, and did some research. God answered me through an organization that raises funds for leukemia research through distance-running events worldwide.

During my four-month training, when I was in the right frame of mind and spirit, I learned to offer up my discomfort. I offered all sacrifices related to my efforts as prayers for those fighting this horrific disease.

As the mileage got longer, I would spend a few hours moving along at a steady pace and at times remembered to thank God for the gifts of life, my family, and the ability to run. Once I got warmed up, no matter how early or how long the distance, I enjoyed it.

The training could be grueling, but that was not the toughest part for me. I retired from the Marine Corps, and aching body parts come with the territory. The real challenge was the required fundraising. I had to swallow my pride and practice humility when I contacted friends for donations. Asking for money, even for such a compelling reason, was extremely tough, and through it I learned that offering up pain goes beyond the physical.

I now attempt to practice this type of prayer in some form every day. Sometimes I offer up a stiff knee with a smile instead of a groan or a walk up the stairs when I would rather take the elevator. These prayers may be for my parents' health, my daughter's test at school, or my wife to have a good day. When I have discomfort related to my physical training, I still try to offer it up for Joseph.

I have a long way to go but have on occasion even offered up a deep breath instead of seething impatience when stuck in traffic. Who knows, this may be even better for my blood pressure than running.