It takes a bit of guts for an active professional athlete to put his faith in a company and invest hard-earned money into something that could ultimately amount to nothing. That is even truer when it comes to investing in a startup. But Indianapolis Colts quarterback Andrew Luck did just that when he became an early investor in BODYARMOR, a sports drink startup that seeks to take market share away from behemoth Gatorade.

I recently discussed the multi-year partnership, that includes an equity component, with Luck and learned about what he was thinking when he decided to make a bold move a few years ago and align himself with an unproven product in the wake of becoming the first overall pick in the NFL Draft.

"While I was still at college, I used to drink it," explains Luck, who went to Stanford. "It was an option outside of the regular stuff that was offered and I really liked it. So as soon as I turned professional, I had my agent reach out to BODYARMOR. He said, 'Hey, Andrew loves this stuff. Would you want to partner up?' They agreed, so it was a very natural, organic partnership."

Importantly, Luck loved the way the product tasted, which is key for an endorser who is going to be "trapped" into only consuming that product within a broader category of goods. It is even more important for someone who has equity in a company, as that person is required to be authentic advocate with a higher potential ceiling for success.

But as an investor, one also must note a brand's weaknesses.

"At the time, it was sort of unproven," admits Luck. "Obviously, with anything you take a leap of faith. But I believed in the product so that was enough reason for me to get behind it. They've done such a great job of growing over the past four or five years. You're really starting to see it explode especially these last couple of quarters."

Additionally, being an active investor allows an individual to have a say in the growth of the company and see direct fruits result from one's labor. While it may be difficult for the quarterback of an NFL to provide insight, Luck finds a way to make it happen.

"My agent and I maintain solid dialogue with them constantly," explains Luck. "They've been very receptive with everything I've had to say. They've been incredibly supportive of me even when things aren't going so well on the field. I always feel like they've had my back. It's been fun having that dialogue."

Recently, BODYARMOR launched its first national TV campaign featuring Kobe Bryant, another investor in the brand. Luck worked with Bryant on the campaign and has been in contact with Bryant since investing in the company.

"Having a guy like Kobe Bryant as part of the brand is great," adds Luck. "Not that the company lacked legitimacy, but when you get a guy of his caliber, basketball acumen and business acumen, I think it adds a certain dynamic that other people can imitate or mimic. He's sharp and he's a great man for BODYARMOR."

Would Luck suggest an investment in an early-stage startup for other active professional athletes?

"I think as an athlete we do have unique opportunities while we're still playing and maybe doors that are open," says Luck. "Some of them you try to take advantage of just like BODYARMOR."