By Melissa Hoppert

Kevin Plank’s sports apparel empire was built on sweat — a lot of it.

After warm-ups and at halftime, Plank, a fullback and linebacker at the University of Maryland in the 1990s, would remove his jersey and pads, and change his soaked cotton undershirt.

“It just seemed like a ridiculous practice, that there had to be a better way,” he said. “And there was.”

Just like that, the seeds were sown for Under Armour, the company he founded in 1996 to manufacture gear that wicks perspiration from the body; it now has about $1 billion in annual revenue.

That Plank, 38, was able pull off such a feat is no surprise. Winning — on the football field, in the business world and even on a horse farm — comes naturally to him.

His love of Maryland and his penchant to fix what is broken led him to his latest project: restoring the state’s horse racing industry.

“I thought someone should do something to help put Maryland racing back on the map,” Plank said. “And I looked around, and frankly I fit the profile. I love broken things, and I love big ideas, and I love long shots. So when everybody’s saying racing’s the worst thing, it’s going away, to me that’s usually the best time to get involved.”

Hampered by failed slot-machine legislation, dwindling purses and threats of losing the Preakness Stakes, Maryland racing was in need of a jolt.

“Kevin is a huge supporter of racing in general, and he’s an avid supporter of Maryland racing,” Tom Chukas, president of the Maryland Jockey Club, said.

“He’s active specifically around the Preakness with hospitality and so on. And he is available to help as we move forward in the horse industry. We’re trying to right the ship.”

Plank’s foray into racing began in earnest in 2007, when he bought a symbol of the sport’s storied past, Sagamore Farm, once owned by the industry titan Alfred G. Vanderbilt.

At the heart of the farm, a 21st-birthday present to Vanderbilt from his mother in 1933, is a cemetery for its beloved champions. They include Native Dancer, winner of 21 of 22 races in the early 1950s and a genetic link to many present-day champions. But the property fell into disrepair after Vanderbilt sold it to a developer in 1986.

Plank tapped his high school friend Tom Mullikin, who had quit his corporate job to work at a horse farm in Kentucky, to manage the restoration of the 530-acre Sagamore Farm in Glyndon, Md.

Fencing was fixed and painted; pastures were treated; a three-quarter-mile Tapeta training track, which is partly made of recycled Under Armour shirts, was installed; and two barns — one for foaling and one for horses in training — were spruced up, with skylights and sliding doors. Restoring a quarter-mile indoor track is next.

The farm’s current crop is 10 broodmares, 7 foals (with one on the way), 7 yearlings, 8 2-year-olds in training, and 12 horses ages 3 to 5 in training.

“Now,” Mullikin said, “we just need to do just one thing — win.”

Although they have a 20-year plan in place, winning at the top level of the sport came fairly quickly for Plank and Mullikin. Shared Account, trained by Graham Motion, beat the heavily favored Midday in the $2 million Breeders’ Cup Filly and Mare Turf in November.

“I still get chills thinking about it,” Mullikin said. “The great thing about horses is they will humble you in a minute.”

After the victory, Plank calmly declared his Maryland mission to a national television audience.

“The light went on, and it was like he’d been doing this for years,” Mullikin said.

Plank added: “I use a statement that says, ‘We’ve always been smart enough to be naïve enough to not know what we can’t accomplish.’ We won the Breeders’ Cup at 46-1. I think the only people that weren’t surprised was us.

“People say: ‘Do you know what a big deal this is? Winning a Breeders’ Cup this early?’ And my reaction to that is no. We expect that. And it’s definitely not arrogance; it’s more of a confidence thing. That’s how you win, that’s attitude, and that’s what we have at Under Armour. And it’s great confidence that allows us to step up and go toe to toe with anybody.”

On the Preakness undercard Saturday, Shared Account made her season debut with a fourth-place finish in the Gallorette Handicap, and Humble and Hungry, named for Plank’s letter sign-off and the Under Armour cafeteria, was second in the James W. Murphy Stakes.

Plank’s goal is to build a barn full of what he calls Sagamore horses, “gritty underdogs that run hard and always grind it out.” His hope is that fans will follow his stable the way football fans root for their teams, no matter who is on the roster. Luckily, a solid base — the historic farm, the Vanderbilt racing silks with three cerise diamonds — was in place.

On Friday, Sagamore’s silks flew past the finish line as All Mettle won the first race on the Black-Eyed Susan undercard at Pimlico.

“I think that certainly he’s taking a step in the right direction just by restoring Sagamore,” Motion said. “There’s an extraordinary history of racing in Maryland, and it’s still very evident in the fact that racing’s so competitive, even though they’ve struggled with the purses over the last few years and as much as keeping up with everybody else.

“So certainly if we had more Kevin Planks, it would go a long way to restoring the industry for everybody, let alone the state of Maryland.”