WATCH: Charles Tillman discusses Bears opener and his 65-mile trek across Lake Michigan

Beyonce was the catalyst in former Bears player Charles Tillman and innovation executive Jacob Beckley’s 65-mile, 25-hour trek across Lake Michigan.

“Single Ladies” provided both entertainment and energy to the duo in the midnight hours of their journey.

“He’s part of the Beyhive,” Tillman said of his rowing partner. “He’s Beyonce’s No. 1 fan. We sang the documentary. We sang that whole album, twice. All night.”

Tillman and Beckley took on the challenge to raise money for pediatric cancer research and also to support families affected by pediatric cancer. They named the cause Row4Kids and the duo raised more than $250,000.

In comparison to all of Tillman’s athletic endeavors, 13-year NFL career included, the former Bears cornerback said this trek ranks second in level of difficulty.

“Making it to the NFL is definitely a lot harder,” Tillman said. “But it’s probably the No. 2 most physical thing I’ve ever had to endure — 25 hours straight, nonstop, it’s pretty taxing on your body.”

At one point Tillman said he was rowing while he slept. Beckley was none the wiser because he said Tillman never fell out of sync.

Despite the team’s success on the water, Tillman said he’s officially retired from rowing.

“[Beckley] goes, ‘Give it a couple months, it’ll settle in and you might change your mind,’ ” Tillman said. “As of now, today, September 9, 2019, I am saying no. I am not doing it again.”

Tillman and Beckley completed the trip last Tuesday, giving the cornerback plenty of time to rest before watching the Bears’ 10-3 season-opening loss against the Packers at Soldier Field.

In Tillman’s eyes, the Bears’ defense played exceptionally. He added that a team can win a lot of games with a defense that stifling. Tillman was slightly more critical of Mitch Trubisky and the Bears offense.

“They weren’t able to get the ball down the field,” Tillman said. “I don’t think we ran the ball enough. Those are just two small observations that I observed.”

As for Week 2, Tillman had one piece of advice for Trubisky as he prepares to face former Bears defensive coordinator Vic Fangio.

“He just has to play his game,” Tillman said. “Some people progress faster than others. I think he’ll be fine, he just has to run his own race.”