Princeton Football Enhances Player Performance with New Polar Tech

  • March 9, 2017


The Princeton football team added a new piece of gear to its uniforms this past season – but it’s something you would never notice. Sixty Tigers have sported small, black sensors underneath their jerseys. The new Polar Team Pro technology is outfitted with GPS and heart rate monitoring to “create the ultimate solution for player performance tracking in team sports,” according to the Polar website.

The Polar sensors provide the Princeton staff with a range of analytics to inform decisions on everything from micro-level individual adjustments to macro-levels changes in practice schedules.

“The first year we were collecting a lot of data and looking at the trends week to week, making sure that we were accomplishing what we set out to accomplish – which was making sure that Tuesday and Wednesday practices in-season are harder workouts, and that Thursday and Friday are easier days,” Varsity Strength Coach Terry Joria said. “That being said, if you consistently see a guy getting crushed as practice, we would say something to Coach Surace or the position coach. They have cut it down on some guys on a case-by-case basis.”

Other macro-level changes can be made on data collected such as recovery time. This is calculated by Polar for each individual, and practices can be spread out to guarantee that all players are fully rested before the next session. This ensures performance is maximized at each practice.

Princeton defense runs drills in recent spring practice. Many of the Princeton Football players wear small sensors underneath their practice gear that track their motion and heart rate.

Data detected by the Polar sensors can be viewed online, where the analytics appear for each individual, but can be sorted by position group or by offense-defense. Every individual has measures for training load, heart rate, max and average speed, distance covered, the number of accelerations, and more. The first three categories are used to inform most decisions made by Princeton coaches and conditioning staff.

“Right now, it’s about developing a base,” Joria said. “We don’t want to overwork them because it’s time for them to make big gains in the weight room. They can get big and strong without doing too much running. Then, we use spring ball to continue to get guys in shape and maintain a certain level.”Fourteen years ago, the 2003 book “Moneyball” by Michael Lewis ’82 was making its first run on the shelves. It chronicled the use of sabermetrics in evaluating baseball players. Now. the new data-driven work is in use by professional NFL teams, despite initial resistance when it expanded to player monitoring. Since then, it has expanded to the college level.

“Football is not a sport where you can take a day off, so, for us, [Polar is about] how can we look at the individual player to get him better and better,” Surace said. “For example, how can we get certain players more reps and give less to others so we don’t overwork them? It allows us to modify the workload by exchanging one player’s reps for another’s and get the best out of each individual player.”  The Polar system is also beneficial for injured athletes, who wear the sensor during recovery. The data is shared with athletic trainers, who can gauge whether recovery workouts are effective.

At the end of Saturday spring practices, players from offense and defense face off in tug-of-war. Those wearing Polar technology can see their workload exerted in these drills, and it also helps the coaches and conditioning staff make individual adjustments or overall changes to practice schedules.

Additionally, the Princeton data is paired with a questionnaire crafted by coaches and Joria’s conditioning staff. The questionnaire is required by each player when they wake up in the morning and measures five pieces of information on sliding scales: sleep, hydration, soreness, stress level, and body weight.“For my entire coaching career I have used the ‘eye test’,” Surace said. “I have watched the guys come in dragging today, wondering if he was up

“For my entire coaching career I have used the ‘eye test,’” Surace said. “I have watched the guys come in dragging today, wondering if he was up late, if he’s tired, if he’s sick – but I never had any proof. Now, I have scientific evidence that can help them. I can see who is sick, who is sore from lifting, or didn’t get enough sleep. I look at the survey, and when combined [with the Polar data], I can see the whole picture.”

Joria is also responsible for a live stream of the Polar data at practice, which allows the players to see their numbers real time. This has helped players compete in categories like max speed or the number of accelerations. Some will also consult with Joria during practices to monitor their own workload and push themselves harder if they’re not happy with the results.

“I want to stress it is not used as punishment,” Surace said. “It is just information. It’s a way for us to have a conversation and see what is going on. All the time, especially guys that are playing a lot in the games, we need to get their workloads at optimum levels so they will be at their best come game day.”