Could health and fitness data from your wearable fitness tracker be used against you in court?

It's quite possible, if a precedent-setting case in Calgary goes to trial.

Lawyers from McLeod Law are representing a woman who was injured in an accident four years ago. They want to submit data from her FitBit to show how her physical abilities have been limited since the accident, with data showing that her activity levels are now lower than the average person of her age.

Data from a wearable health tracker has never before been offered as evidence in a Canadian court.

Civil litigation lawyer Matthew Pearn of Foster & Company said the question for the judge will be how probative, or trustworthy, information from the fitness tracker will be.

"It's an interesting tool that the plaintiffs are using. They're voluntarily giving over a lot of private information that this woman has collected about her health and her fitness," Pearn told CTV's Canada AM from Fredericton.

"I think that with a good explanation of the technology, it's quite possible that a judge might find it reliable, something they can use as a guide to show what limits she has following some form of accident that's affected her life."

Wearable gadgets present privacy risks

Fitness trackers collect a wide swath of data, depending on the type and brand, including distance travelled, speed, heart rate, and blood pressure. Users can upload that data to a number of apps or online programs and include more information, such as diet, weight and mood, to paint a thorough portrait of his or her health status.

As fitness trackers become more popular, the question for the legal community will be how to balance the user's privacy and the relevance of the information in a legal proceeding, such as a personal injury lawsuit, Pearn wrote earlier this year in Claims Canada.

"As wearable technology advances, these devices may truly become the 'black box' for the human body, providing incredible insight into the health, lifestyle and behaviour of the wearer," Pearn wrote.

"But what, if any, privacy rights should the wearers of these high-tech devices maintain over this electronic information once the wearer files a personal injury claim?"

'Personal diary' in courts?

As fitness trackers become more popular and the data more accurate and reliable, they could play an increasingly important role in court, Pearn wrote.

Lawyers and insurance agents must watch the Calgary case and others that may follow closely, to see how courts rule on the admissibility of the information. Also, they may want to see whether the courts allow defendants to compel plaintiffs to turn over such data.

"This is like a personal diary that keeps track of a person's life in a kind of way that's entirely new, Pearn said.