Research using wearable technology could shed more light on the matter. Major soccer leagues have been using wearable tech to track players’ movements for over a decade. In the early 2000s, sports medicine researchers equipped women at local universities in North Carolina with cellphone-sized GPS receivers and heart rate monitors to measure players’ effort and average running distance. One study found that players were moving almost nine thousand meters per game, with an average heart rate of 150-170 beats per minute; one woman on the national team clocked in an average of 190 b.p.m. for an entire match. (For reference, the average resting heart rate is between 60 and 100 beats per minute). The results showed that the most physically-demanding period of a match is when a player is in control of the ball, evidence of soccer’s demand for a balance of technical skill and physical conditioning — but that comes as no surprise to anyone who’s played “the beautiful game.”
Major League Soccer’s Seattle Sounders are one example of a team on the ‘cutting-edge’ of wearable tech research. The Sounders play on turf and, for this reason, French soccer legend Thierry Henry has refused to play in Seattle, to prevent aggravating a chronic Achilles injury; he described Seattle’s field as “severe,” and compared it to a synthetic running track, or “playing around my house.” Seattle’s coaching staff is aware of the dangers: they use data from wearables worn during practices to shape a training regimen that achieves optimal results while minimizing risk of injury — and they sometimes decide not to sign players with past injuries that tend to flare up on turf. So far, the results seem to speak for themselves: over three years, the number of days that Sounders players have been benched for muscle injuries has declined by more than half.