We shadowed a bunch of Wall Streeters during an early-morning training session for the most intense competition out there

Inside a 6 a.m. training session at Tone House.Sarah Jacobs

The D10 is an intense competition that pushes its athletic contestants to their ultimate physical limits.

It takes place in five cities across the US, and while the New York City D10 isn’t until June, training for the competition — a 400-meter run, football throw, pull-ups, 40-yard dash, dips, 500-meter row, vertical jump, 20-yard shuttle, bench press, and 800-meter run — begins long before that. The event is a favorite among the Wall Street crowd, and its goal of raising money to support pediatric cancer research is a major draw for many.

“The D10 is important to me for so many reasons; the main one being a personal pursuit to play a more active role in the fight against cancer,” Samantha Santaniello, who works in data sourcing and strategy at Point72 Asset Management, told Business Insider.

We recently caught up with some of the the New York City contestants during a 6 a.m. training sessions at Tone House‘s Upper East Side location. Ahead, take a look at the intense 60-minute workout they use to up their physical endurance for the D10.