Are you a fitness freak? May be yes, may be no. Whatever you are you don't want to fall sick and lose on a day's salary, right? Many people do exercise, maintain a proper diet and try to detect the signs of falling sick. But even for the most dedicates fitness freaks, it's nearly impossible to track heart rate, skin temperature and other signs all day, everyday – unless you have a smart watch to so that for you.

Researchers, led by Stanford's Michael Snyder have just published a study, according to which these watchful wrist-based smart gadgets can help both monitor and diagnose health issues beforehand.

These new wave of portable biosensors allows frequent measurement of health-related physiology. So, by the use of these devices it is possible to monitor human physiological changes during various activities and their role in managing health and diagnosing and analyzing disease.

As many as 43 people participated in the experiment for two years during which, various measurements were taken regularly and correlated with real-world events like travel, sleep trouble, sickness and so on. What the researchers found was that, smartwatches may be a very useful way to monitor general health — as long as their role is carefully considered.

For instance, during air travel, people tended to show lower blood oxygen levels, resulting in fatigue. The onset of Lyme disease was able to be tracked, and individuals' sensitivity to insulin (and thus risk for type 2 diabetes) was also evident from the physiological measurements.

You may be able to tell when you are doing down, but with proper use smartwatches can tell you hours or days before you might have noticed. It wouldn't be a diagnosis per se, but simply a warning that it's data readings are out of the norm and so you might need to take rest or a good night sleep in order to avoid getting a cold.

"Overall, these results indicate that portable biosensors provide useful information for monitoring personal activities and physiology," wrote the researchers in the paper, published in PLOS Biology, "and are likely to play an important role in managing health and enabling affordable health care access to groups traditionally limited by socioeconomic class or remote geography."

The Stanford team is now working on creating algorithms that could do this reliably.