Bob Montgomery's motto is, "You don't know what you can do."

For most of his life, Montgomery had been in excellent shape. However, in the mid 1990s, his exercise regimen began to slack and by the start of the new century he could not believe how out of shape he had become.

Through the use of the company gym, Montgomery regained his form and was soon keeping up with his younger coworkers. He began doing push-ups as a way to work his entire body.

One day, Montgomery did 300 push-ups.

"I thought, 'If I can do 300 in one day, why can't I do 50,000 in 2012?," Montgomery said. Shortly thereafter, he decided to up the ante and do 55,000 pushups in honor of his 55th birthday. He set up a blog where he encouraged visitors to donate to a charity of their choice.

Around this time, the mission of personal fitness was permanently altered when Montgomery's father in law Eugene Rundquist was diagnosed with Stage IV lung cancer after a long period of declining health. He was given nine months to live, but died two months and a day after the diagnosis.

"I told him on his deathbed that I was going to do 55,000 push-ups in 2012 for him and raise $1 million for cancer research," Montgomery said.

Although Montgomery has passed the 50,000 push-up mark, donations have not kept pace. Despite an increase in media attention, he has raised only $500 for the American Cancer Society.

Montgomery hopes that increased media exposure will help his project go viral; he contends that if a "dog doing back flips" can get 5 million YouTube views, he hope that his project will do the same thing and receive a torrent of donations.

There's another goal for Montgomery in this push-up quest. He hopes to raise awareness not only of cancer, but of early detection of cancer and getting over the fear of being labelled a hypochondriac for doctor visits on seemingly routine issues.

"If one person goes to the doctor and has an early stage cancer detected because of what I'm doing, then it's all worth it," he said.

Regardless of the monetary outcome of the project, it has been worth it for Mongtomery to discover what he as a person is capable of doing, and what people over 50 can do to develop and maintain a healthy lifestyle.

"If anyone had told me five years ago that I'd do 55,000 push-ups in 2012, I'd have said they're crazy," Montgomery said. "But now, I don't know how many I can do."

If you are interested in following Montgomery's progress, follow him on Twitter and like him on Facebook. A link to his blog was provided earlier in the article.