Vols football staff monitors players' workloads with GPS, satellite systems

Computer monitors display information from the Catapult GPS tracking system on the sideline during Tennesee's practice Friday in Knoxville.
Computer monitors display information from the Catapult GPS tracking system on the sideline during Tennesee's practice Friday in Knoxville.

KNOXVILLE - Brad Roll has been around football for decades, watching the game change and changing with it.

A former strength coach for four NFL franchises, he is now roaming the football complex at the University of Tennessee, having evolved into a technology guru with the job title of GPS analyst.

"Data is king," he said this past week.

Roll is in his second year overseeing Tennessee's Catapult GPS and Zebra satellite tracking systems that record the effort exerted by players at practice and in games. Roll tracks distances and speeds run by using modules placed in players' shoulder pads or helmets and can hone in to decipher how far and how fast a certain player ran on a given play.

He uses the data to build detailed reports that can span weeks in some cases and give position coaches insight on their players. The technology can help reveal who is at risk for overworking in practice and those who are not getting the amount of work they need to continue developing.

Volunteers coach Butch Jones is an advocate of sports science, and the tracking systems have been a mainstay in the program during his five-year tenure. Coaches may be paying especially close attention to the data this year after an injury-plagued 2016 season.

"The most important thing during training camp is to keep players healthy and engaged," said Roll, who has been at each preseason practice, monitoring screens that show the real-time efforts of the participating players. "So right now our biggest parameters are duration, total distance and the hard-effort distance yards."

Hard-effort distance yards are based on a formula that takes NFL performance speed averages into account. For example, Tennessee uses 20 mph as a benchmark for wide receivers. Yards run at 65 percent of that (13 mph) or better are considered hard-effort distance yards.

If a player racks up too many total yards or too many hard-effort distance yards during practice, coaches will consider limiting the player to keep him game ready.

All 32 NFL stadiums are equipped to use the Zebra system during games, but Tennessee's Neyland Stadium is the only venue in the Southeastern Conference like that, Roll said.

Rock Gullickson, the Vols' strength and conditioning coach, is familiar with the technology from his time in the NFL, most recently as the Rams' strength coach. He noted sophomore wide receiver Marquez Callaway, who is also a punt returner, had "a huge day" during Tennessee's first practice in late July.

"You're like, 'OK let's keep an eye on him right away' because he put on thousands and thousands of yards on day one," Gullickson said. "So you get instant ideas that you might have to limit his reps day two just because of the workload he took on. But you expect that from football players on day one. They're excited, they're together, it's season, we're getting ready to play a game and it's real now. Day one, they want to show that they've put in the time and effort during the offseason.

"They're going to run fast and be tireless, but you need to have an idea that to avoid those fatigue injuries and soft-tissue injuries that we all kind of brace for, there needs to be time to recover a little bit."

Gullickson said what he finds most interesting about the Catapult and Zebra systems is the players' interest in the instant feedback the programs give. Roll places information from the most recent practice on the window of his office, and Gullickson has noticed players reading the information and comparing distances and speeds.

Senior safety Todd Kelly Jr. said he likes the technology because it shows how hard players are working.

"It's all about competing, not just on the field but off the field as well," Kelly said. "With that comes the GPS system. We see who has the fastest velocity. I tell the guys it's all about burst and acceleration. Force equals mass times acceleration. It's all about that.

"When you go out and give your all and go hard, it's huge, and then we look at the end of the day and see who made the biggest hit and why they did it."

Contact David Cobb at dcobb@timesfreepress.com.

Upcoming Events