CHARLOTTE, N.C. -- Carolina Panthers linebacker Luke Kuechly reached behind his head and pulled a small, red device labeled "LK59" from a pouch in the middle of his shoulder pads.
The two-time Pro Bowler couldn't wait to learn what the device registered in terms of how fast he ran and how much ground he covered during the two-hour practice.
"The thing we have the most fun with in the backer room is who ran the fastest," Kuechly said with a smile.
The GPS device is called a Viper pod. Designed by a company in Ireland, it fits comfortably in your hand. In terms of the amount of knowledge it provides to head athletic trainer Ryan Vermillion and the coaching staff, it's like holding the world.
Science has changed Vermillion's job significantly over the past 20 years. But nothing has changed it like the GPS technology that is spreading throughout the NFL.
The Panthers experimented with it on two players a year ago. All 90 who reported to training camp last month are fitted with it.
Among the seemingly countless things the device registers are heart rate, acceleration and deceleration, the amount of load experienced on impact, the amount of force applied to one foot versus the other, fatigue level, how much ground is covered and how much of that was at peak performance versus a jog or walk.
If Vermillion wanted, he could end the debate over whether Ted Ginn Jr. or Corey Brown is the fastest Carolina player.
"You can get a little paralysis by analysis it does so much," Vermillion said. "We brought it down to about 10 items that we're looking at."
Vermillion hired Bret Nenaber, an athletic performance analyst, to oversee reading the data daily. The two take that information to coach Ron Rivera with suggestions on whether a player needs to adjust his practice reps or take a day off.
The information also helps determine how long certain drills should last in order to get peak performance.
The information gathered from defensive end Charles Johnson (calf) and wide receiver Devin Funchess (hamstring) on Wednesday as both returned to practice will be used to determine if they are at risk should they play in Friday night's preseason game against New England.
The main goal is to reduce the risk of injury and to create a workload that will create maximum performance.
For example, when the Panthers were without starting defensive tackles Kawann Short (back) and Star Lotulelei (foot), the workload on others had to be adjusted.
"Player X is handling stress very well. Player Y isn't. Why isn't he?" Vermillion said. "He has two other players at his position that are injured so his repetitions have increased. That's something the coaches need to understand."
Most teams use some form of GPS. The NFL hasn't approved it for teams to use in games and teams haven't reached the capability of monitoring the numbers live as some soccer and rugby teams do.
"I'm sure that's where we're going," Vermillion said. "I could imagine going up during practice and going, 'Hey, we need to pull back some.'"
Vermillion would like to believe the technology has helped prevent the Panthers from having more serious injuries in training camp.
He reminds the ACL tears suffered by wide receivers Kelvin Benjamin and Stephen Hill are considered freak accidents since there was no contact involved.
Rivera admittedly is old school, "one of those guys that says, 'Well, you know, back in my day.'"
He also appreciates the possibilities GPS science has created.
"Now there's so much awareness, 'Ah, his numbers were high, he's got a huge workload and his recovery time isn't as good'," Rivera said. "It's crazy. It measures so much."
Kuechly believes GPS benefits the older players more than 24-year-olds like him. Perhaps that's because he's in such good shape that the numbers don't surprise him.
He still likes to check them out to see how consistent he was in practice.
"But the cool thing for me is how fast you ran," said Kuechly, again smiling, "We just don't tell AG [Adarius Glanton] how fast he is, because AG can move."