The sports marketing world obsesses over finding the right fit between brand and endorser. Does the athlete truly enjoy using the brand? Is the product or service something that the athlete will use on a day-to-day basis? Should the brand be concerned with the athlete using a competitor's goods?

These are all questions that marketing executives stress over when determining whether it is money well spent in an endorsement contract. As the Indianapolis 500 approaches, there is one brand with no such concerns.

Meet Charlie Kimball and Novo Nordisk. An athlete endorsement relationship like none other.

What is so special about an IndyCar driver pushing a pharmaceutical brand?

"The really special relationship with Novo Nordisk is that it's not just something I choose," explained Kimball, the first licensed IndyCar driver with diabetes to start the Indianapolis 500. "It's not a cell phone provider, another tech company or retail store. I need insulin to manage my diabetes and blood sugar every day, whether I'm at the race track, gym, at an appearance or home. I always have a relationship with Novo Nordisk whether people see it or not."

Kimball is in the sixth year of a partnership with Novo Nordisk, which includes more than the brand simply slapping a sticker on Kimball's car and a hat on his head. It entails Kimball speaking to the diabetes community and health care professionals so that families with diabetes hopefully have inspiration to chase their dreams.

Kimball partnered with Novo Nordisk to launch the educational program Race with Insulin, encouraging diabetes patients who use insulin and caregivers to pledge to talk to their health care professional about options for insulin delivery.

"Novo Nordisk has a place in my heart and my pancreas," said Kimball. "The fact that it's a product that I have to use every day is the biggest piece."

Kimball contrasts his relationship with Novo Nordisk to an athlete endorsing a brand like Pennzoil, which has been around motor racing for what seems like eternity.

"Do I change my own oil in my Chevy pickup? No. But does the dealership use Penzoil? I don't know," explained Kimball. "With my insulin, I know absolutely and completely that I use it every day and it's not just because I need it for the maintenance of my car and phone or whatever. I have to use it to manage my diabetes so that I am healthy and competitive as an athlete and live as a person. That story of how I use their insulin to manage my diabetes to go racing is transcendent. It transcends motor sports."

Communication crafted the perfect partnership.

Kimball first heard about Novo Nordisk on the day he was diagnosed with diabetes in October 2007. He vividly recalls walking into a clinic to receive his first insulin injection and noticing the Novo Nordisk name on the wall. That's when an informal relationship began between Kimball and the pharmaceutical company.

In January 2008, Kimball saw an endocrinologist in California who said that knew some people at Novo Nordisk and offered to send an email to tell them Kimball's story -- diagnosed with diabetes at age of 22; used insulin since being diagnosed; professional race car driver. That started a conversation with them.

"First it was about outreach and how to connect to the community . . . how they could continue to support the diabetes community through me," explained Kimball. "I knew very little about how the pharmaceutical industry as a business worked. They knew very little about how motor sports as a business worked."

Kimball's formal relationship with Novo Nordisk began in January 2009. The brand appeared on his race car in May of that year. In 2011, Novo Nordisk was alongside Kimball as he made the progression to IndyCar Series racing.

Endorsements are the life blood of motor sports.

Race car drivers are only given the opportunity to drive if they are able to gather up the requisite funding to race. That is why it is so important for drivers to craft strong endorsement relationships. It allows the athletes to survive in their sport. That's more true for Kimball than others.

In his car, Kimball has two drinks tubes that connect to a drinks line fed into his helmet. While racing, he has the option of plain water or sugar water (should his blood sugar levels drop) for hydration. He also has a continuous glucose monitor mounted on his steering wheel which provides blood sugar level readings during races.

Kimball needs Novo Nordisk, but the company also needs Kimball.

"I think the industry for drivers has changed," said Kimball, who finished in third at the 2015 Indianapolis 500. "Over the last 10-20 years, it's no longer enough for a driver to show up, get in a race car, win the race, take one picture and fly home. You have to be successful in the boardroom to be in the race, let alone have a chance to win the race. As drivers, we are brand ambassadors that are forward facing for the company. It takes time for those relationships to develop."

Kimball's relationship with Novo Nordisk has been steadily growing for almost a decade, even before Novo Nordisk executives knew about the current IndyCar driver. If Kimball improves on his performance from last year's Indianapolis 500, then many more will likely learn about this perfect partnership.