IMG is at the forefront. It is trying to enhance its academy brand with football, perhaps the most visible sport. And it is applying a business model to the gridiron that has long been profitable for tennis and has expanded to golf, soccer, baseball, basketball, lacrosse, and track and field. The academy has nearly 1,000 students from more than 80 countries enrolled in prekindergarten through 12th grade and postgraduation. About half the students are international.

The school, 45 miles south of Tampa, recruits football players from around the country. It offers high-performance training, college preparatory courses, coaches with N.F.L. playing experience, facilities that resemble a small college more than a high school, and a chance to play a national schedule and on ESPN against some of the highest-rated teams.

Though IMG Academy has fielded a varsity football team for only three seasons and, as an independent school, is ineligible to play for a Florida state championship, it is stocked with six of the nation’s top 100 senior recruits. The roster has players from 21 states and six countries. This month, IMG flew to Texas for a game. On Saturday, it traveled to New Jersey and defeated another power, Bergen Catholic High School, 59-47.

The full cost of tuition and boarding for a year of football at IMG Academy is $70,800, although need-based financial assistance is available. School officials would not provide specific figures, but they said that payments by families could range from tens of thousands of dollars to a competition fee (from $3,750 to $4,500) to nothing.

Team helmets are adorned not with a lion or a tiger but with IMG’s corporate logo. The cheerleaders and the pep band come not from the school but are themselves all-star performers from the area. Even the team nickname, the Ascenders, suggests players are there with college in mind.

The academy was founded in 1978 by Nick Bollettieri as a tennis boarding school on what he often says were 15 acres of repurposed tomato fields. Andre Agassi, Serena Williams and Maria Sharapova have trained there.