Statistics in sports is about to hit a whole new level. A new generation of wearable monitors that measure heart rate, electrical activity in the heart, lung capacity, metabolism, and other metrics is allowing scientists to study athletes’ physiology as they play.

The data has obvious potential to enhance players’ health, and to help trainers tailor workouts, but device makers and the sports industry seem most excited about the prospects for entertainment. They are already working on ways to display the data during games, in stadiums and on television, giving fans unprecedented insight into players.

Last February, when the NFL held its annual scouting combine to assess the top-ranked college players, the highest-profile draftees wore special shirts fitted with sensor technology, developed by Under Armour and Zephyr Technologies. The players’ data—such as acceleration during the first 10 yards of the 40-yard dash—was recorded as they ran through the various physical trials.

“Millions of dollars in decisions are made based on the 40-yard dash,” says Leslie Saxon, a cardiologist and director of the center for body computing at the University of Southern California, who led a panel on sports and body sensors at a conference held there last week. “If you can get much more sophisticated statistics on body position, physiology, and mechanics, I think it could play a big role.”

Zephyr started out six years ago developing wearable monitors for the Special Forces. But thanks to cheaper sensors and wireless radio technology—changes that have already spawned a new movement in self-monitoring among ordinary people—the company is moving toward the professional sports and consumer market.

“Athletes want feedback immediately, and they get competitive quickly,” says Brian Russell, Zephyr’s CEO. “I am convinced it helps them perform better because they are getting measured.”

The latest version of the technology is made up of a sleek disc—about the size of a compact—that holds sensors for heart rate, temperature, and movement, along with a power source, Bluetooth transmitter, and memory storage. The device is paired with fabric electrodes embedded in a chest strap, shirt, or bra. In conjunction with sophisticated software, the technology can measure heart vitals, as well as anaerobic threshold and aerobic capacity.

Russell says more than 50 college and professional sports teams around the country, from football and basketball to volleyball and hockey, are using the technology to monitor their players. The data helps with the athletes’ safety—heart rate can be used to predict dehydration, for example, which is linked to sudden cardiac death in young athletes. And trainers aim to use it to make workouts more efficient for individual players.

“That’s the trend in both medicine and sports,” says Russell. “Because you can measure it, you can personalize it.” For example, the device can tell the coach if the wearer is above or below anaerobic threshold, when muscles start producing lactic acid and therefore take longer to recover. “You can put them in the tight training zone for peak fitness and no injury,” says Russell.

However, the technology is new enough that scientists and coaches are still figuring out how to use the data. “No one knows what a normal basketball game looks like,” says Mitch Hauschildt, a strength and conditioning coach at Missouri State University who uses Zephyr’s device on his players.

Saxon, a cardiologist, aims to use the technology to better understand how an elite athlete’s heart behaves under the stress of playing the game. “We want to create a safer playing field for everyone, to be able to prolong athletes’ careers and understand how to train them better,” she says. “We know from sudden cardiac death there is something of a perfect storm in game play.”

Last month, Saxon put wireless electrocardiograph patches on USC’s football team for a week, including games. The endeavor was a proof of principle demonstration for a larger project funded by the NFL. “This type of study has never been done, not on a whole team,” says Saxon. Researchers plan to analyze, for example, what happens to a player’s physiological signs when he’s tackled.

Beyond safety and training, wearable sensors make it possible to broadcast a player’s physiological stats in real time, and that could add a new dimension to watching games, betting, and creating fantasy teams.

“Fans do really want to be engaged with players,” said Asim Pasha, chief information officer of a Kansas City soccer team that plays in the highly wired Livestrong Sporting Park, at the body computing conference. “Anytime they can get more information, it’s a definite plus.”

“It could have a huge impact in driving sponsorships,” adds David Carter, executive director of the USC Sports Business Institute. But there’s still a debate about who owns that data—the athlete, the team, the league, or the sponsor.

So far, athletes seem excited about the possibility. “Players know that if they share data, they get better television coverage and a better contract,” says Russell. It doesn’t hurt that the shirt, with its futuristic puck centered on the chest, looks good. “They say they feel like Iron Man,” he says.