The iPod of Health Trackers
Official details of the iWatch are still under wraps. Whether it's square or round is based on function – how close the sensors are to the skin – not style.
Credit: Illustration by Eric Paul

The iPod of Health Trackers

Tech giants and start-ups are vying for the lead in the multibillion-dollar body-monitoring market, but Silicon Valley experts say Apple's iWatch, rumored to debut in October, could change everything. “If Apple delivers, this could be to health tracking what the iPod was to music,” says Mark Gurman, a senior editor with website 9to5Mac.

Though popular, the trackers out now are often inaccurate and don't give advanced fitness metrics. “Current wearables can't tell you how fatigued your body is, how your diet affects your health, or what's happening in your blood,” says Joe Kiani, CEO of Masimo, an Irvine, California–based manufacturer of noninvasive medical devices.

Will the iWatch solve those problems? We can take a guess by looking at the biometric-device experts Apple has assembled over the past year or so. In July 2013, the company hired Dr. Michael O'Reilly, the former chief medical officer of Masimo and a part of the company's research into pulse oximetry, which measures the amount of oxygen in the blood. A device with a pulse-oximetry sensor would allow athletes to track their blood O2 levels while training at elevation and monitor muscle fatigue from a tough workout.

RELATED: Why Apple is About to Make Your Fitness Tracker Obsolete

Another key hire: Ravi Narasimhan, former vice president of Vital Connect, a Silicon Valley–based maker of wearable biosensors. The company recently released a wireless patch able to detect heart rate, body temperature, respiratory rate, sleep staging, posture, and even the intensity of a fall. Current devices are unable to tell the difference between, say, a heavy dead lift and bending over to tie a shoe. A wearable equipped with a sensor like Vital Connect's potentially could, which would provide users with far more accurate data than they can get now.

To attack sleep metrics, Apple poached scientist Roy J.E.M. Raymann from electronics giant Philips. Raymann created Philips' sleep laboratory, where he led research into how we can more accurately monitor temperature, hormone production, and circadian rhythms to boost sleep quality.

Perhaps Apple's most important hire is hardware developer Nancy Dougherty, of San Francisco start-up Sano Intelligence, which created one of the most sophisticated sensors yet, capable of tracking kidney and liver function, measuring electrolytes, and determining, in real time, the amount of sugar in the blood. This is where Apple could really raise the bar. Reading blood glucose could help users fine-tune their diets and take steps to reduce the risk of heart disease, cancer, and Alzheimer's. “Glucose is the holy grail of diagnostics,” says Zeev Zalevsky, of Israel's Bar-Ilan University, who studies blood sugar–monitoring devices. Put another way, the iWatch might be able to tell you which beer will really make you put on pounds: Corona or your favorite craft IPA.

RELATED: What Fitness Tracker Is Best for You?

Apple, of course, is not the only tech giant with a souped-up health tracker on the way. Both Samsung and Google have announced future bio-monitoring devices of their own. The Samsung Simband will reportedly have optical sensors embedded in its strap that will use a light to “see through skin” to track heart rate, blood oxygen levels, respiration, and hydration. This futuristic watch, however, has no release data and is simply called a “reference design” by the company.

And Google's Android Wear (watches that will be produced by Motorola, LG, and likely Samsung), will allow you to use voice command to access heart rate, calorie burn, exercise intensity, and data from any other health-tracking apps you have. Microsoft is also creating a yet-to-be-named watch that uses an optical sensor similar to what's in its XBox Kinect to sync with your smartphone to provide heart rate and other biometrics.

There's a veritable arms race to your wrist, but the question is: Can anyone produce a device worth keeping there? In a few months, you may look down — check your O2 levels, muscle fatigue, blood sugar, and more — and know the answer.

Inside the iWatch
A few revolutionary features it may have:

  • Monitor Blood Sugar
    With this data, you'd see how what you eat affects your health, immediately and long-term.
  • Read Body Temperature
    Helpful to know if you're sick, and for better sleep (a degree up or down in body temp can cause fitful rest).
  • Measure O2 Levels
    A stat that helps you determine if you're fully recovered from exercise; crucial for optimum workout results.
  • Detect Muscle Engagement
    Know how hard you're working when you lift or, say, do a wall sit.
  • Get Hydration Levels
    This handy cue to drink more water could up exercise performance and better your mood.