Heart Rate Sensor Assists U.S. Women’s National Team

The United States women’s national team won their third World Cup title this summer in Canada. That same Women’s World Cup, along with this summer’s Under 20 World Cup in New Zealand, marked the first time FIFA allowed players to wear tracking devices during game action. The success of the devices during these events led FIFA to greenlight the use of wearables in future competitions, subject to the approval of individual leagues.

Part of the team’s success was the players’ dedication to the training plans developed by strength and fitness coach Dawn Scott.

“I think it’s a testament to the players that they trusted us and stuck to the program, and did what they needed to even when they had their commitments with their [club] teams,” Scott said in a previous interview.

An earlier Wired article discussed the USWNT’s relationship with Polar Global devices. When reached for comment, Polar Global’s Josh Simonsen confirmed that the players were wearing the H7 heart rate monitor on the pitch, and using M400 GPS watches in training sessions. Simonsen, the company’s national training resource specialist for the U.S., said the Finnish company had worked with Scott and the USWNT since 2010.

“What that gave Dawn was the ability to track speed, distance, and activity of the athlete while they’re away,” Simonsen said. “And they were able to send it her in a much easier environment than the previous models.”

The H7, the heart rate monitor worn during the games, consists of a strap worn across the chest and a small transmitter a few inches wide. The strap contains an electrode that collects the ECG signal from the athlete; after some basic processing, the transmitter then sends out a Bluetooth signal. The system reports heart rate on a per-second basis, using only basic peak-to-peak measurements, which are less susceptible to the kind of movement artifacts you would expect with an athlete wearing the device during competitions.

Polar’s top-of-the-line system, the Team Pro, also includes a GPS and IMU sensor. Switching to Bluetooth Smart also allows the transmitters to communicate directly with a tablet. But Simonsen said the USWNT was still using the older Team2 solution this summer.

“They didn’t want to transition prior to the World Cup,” he said.

The company has a long history with heart rate sensors, having built the first monitor for an athlete in 1977. But it was not until the early 2000s that Polar began developing systems for whole teams, rather than for individuals.

“Essentially the coach would log into the software and each player would have their own page, but they really weren’t able to compare the team as a whole,” Simonsen said. “We couldn’t look at the big picture.”

This functionality would not become available until Polar’s Team2 system was introduced in 2009. Unlike their previous offerings, Team2 allowed coaches to collect and analyze data in much less time. The addition of Bluetooth transmitters also allowed coaches to monitor their players in real time.

“[Team2] was like a 50 percent cut in time that it took to do everything,” Simonsen said. “Everything was exponentially faster.”

The Team2 system is currently used by “about 450 teams” in the U.S., and Simonsen said new coaches are typically surprised by the feedback provided by the data.

“A lot of the time they’re just blown away at how long things were or how hard things truly are,” he said. “Or that their easy day really wasn’t that easy, or that their hard day was a lot harder than they really thought it was.”

Simonsen argues that this experience in the field is what separates Polar Global from the plethora of other companies offering heart rate monitors.

“We created heart rate,” Simonsen said. “And with us using HR from the beginning, accuracy is always our number one thing.”