Over a 90-minute soccer match, Sweden’s Zlatan Ibrahimovic makes dozens of feints, false starts, and other fine movements in an attempt to free himself from opposing defenders. Each motion requires Ibrahimovic to accelerate, and then decelerate, his 209-pound frame forward or backward, left or right. Each effort takes a toll on his body that Paul Balsom, the head of performance for the Swedish national team, cannot track.
“Really, football is all about those movements,” said Balsom, who is responsible for keeping Ibrahimovic on the field and out of the trainer’s room. “We’re not getting enough information.