FOXBOROUGH, Mass. – Without fail, every single week the same sequence of events plays out on the New England Revolution’s social media channels.

A photo of a player on the training ground is posted to Instagram, or Twitter, or Facebook, and when the comments begin to roll in, there’s one remark you’re guaranteed to find. Every. Single. Time.

“Hahaha! Why are they wearing sports bras?!?!”

The answer, of course, is that the players aren’t wearing sports bras. They might

look like sports bras, but in fact they’re athletic vests designed to hold GPS trackers. Those vests need to be skintight so the pod that actually acquires the data – which is slipped into the back of the vest – can monitor players’ performance.

Hence, the sports bra look.

As for what kind of data the GPS trackers provide, there’s the simple answer – heartrate, distance covered, speed, etc. – and one that’s much more detailed.

“Most people typically immediately point out, ‘Hey, I can tell how far a player is running.’ That’s a small part of it,” said

Jarryd Phillips, who joined the Revolution in June as their Director of Sports Performance after several years with Seattle Sounders FC and Minnesota United FC. “But from there you can go a little bit deeper and you can break those distances down into various categories.”

Phillips, who estimates he’s been working with the GPS trackers for six or seven years, said that beyond the GPS system there are also accelerometers and gyroscopes within the pod, which provide information on how hard players are accelerating and decelerating, and how much strain they’re putting on their muscles.

“You can either get very simple data that can just tell you typical outcomes from that, or you can use that data to create your own various custom metrics to create a holistic view of the day-to-day training process, the weekly training process, the monthly training process,” said Phillips. “Just a game or just a training session is a very, very small part of how we’re using it in the bigger scope of things.”

In fact, Phillips rarely uses data from an individual training session or game to reach any sort of conclusions. Instead, metrics are gathered and analyzed over a period of time, and based on the patterns Phillips sees developing, he can then tailor workouts to each individual player.

That individualization is the key.

“An outside back may need this work, or a center back may need this work, your center mid may need this type of work – and it can all vary,” Phillips said. “It’s really important to paint those individual pictures of where the guys are, versus just what’s coming out of the GPS system on any given day. We basically use it as a means to give us more information as to a better way forward with the group.”

The GPS tracking system – the Revolution use a company called STATSports – does have the capability to provide real-time data, but MLS teams do not currently track the system live in-game. Instead, all of the data is accumulated after each match and training session, and compiled into a larger picture.

It’s a picture that’s critical for Phillips and the coaching staff as they map out their workout plan each week, and it can also be valuable information for the players themselves. While some have no interest in their metrics, Phillips said the data is a “complete open book,” and if a player requests to see their numbers, he’ll happily provide them.

As for the vests that hold the pods – the ones that look like sports bras – the players have been wearing them for so long that they’ve simply become part of the uniform. In fact,

Jalil Anibaba said it now feels stranger to play without the vest, almost like something’s missing when it’s not there.

Phillips, just a few months into his tenure with the Revolution, said he’s still in the process of getting the sports performance department operating at peak capability, but said they’ll be “firing on all cylinders” by the beginning of the 2020 campaign.

The GPS trackers are a significant piece of that puzzle.

“It basically just helps you tell the story of where the guys were, to where they are, and where they need to go,” Phillips said.