A couple of hours have passed since Dan Gateno sat down at his desk when he feels a gentle buzzing sensation on his wrist. It’s the fitness tracker he is wearing sending him an alert, so he gets up and walks a quick lap of his office building before settling back down to his work again. 

My job is quite sedentary and I used to find myself sitting at my desk all day 

The 43-year-old mainframe technology manager at IBM was given the device 10 months ago as part of a scheme run by his employer. He is one of the millions of employees around the world who have signed up to wear fitness trackers as part of their company's wellness programme. 

Under these schemes, sensor-filled wristbands like FitBits and the tracker UP by Jawbone are offered to workers at subsidised prices, or even given out free, to help encourage them to stay fit and healthy. Staff who sign up can choose to upload their data to a company website so they can compare their activity to those they work with. Firms can even set challenges for their workers, such as reaching a certain number of steps over a month, or pitch teams of staff against each other in friendly competition. 

“My job is quite sedentary and I used to find myself sitting at my desk all day,” says Gateno, who worked an average 8-9-hour day based at IBM’s site in Rochester, Minnesota. “Being able to use the tracker, see how many steps I have done compared to others in the company has inspired me and others to get a lot more active.” 

A laudable idea perhaps - these companies are taking an interest in their employees’ wellbeing and encouraging their staff to move around rather than be stuck at their desks all day. For the employers, it makes sense. There is good evidence that regular exercise can improve memory, reduce stress, boost productivity and increase performance at work. There are clearly benefits for the employee too - they get to be fitter and healthier. 

 

There are some, however, who worry that by giving employees technology that is capable of tracking their movements and sleep, employers may be crossing a line. Should companies be invading your private life to this extent and compiling this sort of data on their employees? And should your boss really be trying to make you into a better person? 

While fitness trackers have been available for consumers for a while they only popped up in the workplace a few years back as companies looked to find ways of helping them track progress in their wellness schemes designed to improve the health of their workforce.

“About nine to ten years ago, we started hearing from employers who wanted to use our technology to improve participation and track progress in their wellness programmes,” says Amy McDonough, senior vice president of strategy and operations for Fitbit Health Solutions, one of the leading providers of fitness trackers to these corporate schemes. “We are now seeing them being used in all sorts of industries - finance, oil and gas, even hospitals and universities.” 

Last year alone, FitBit worked with 70 major companies within the Fortune 500 and 1,300 other businesses to set up schemes where its wearable devices were used by employees. An estimated 73% of employers in the US now offer some sort of healthy living plan for  staff as part of their benefits package and 8% of those provide fitness tracking bands. While in Europe and elsewhere in the world the figures are slightly lower, workplace wellness globally was worth $43.3 billion in 2015, according to the latest figures. The sector grew by 6.4% in two years, a rise from $40.7 billion in 2013. 

Should your boss really be trying to make you into a better person?

Companies such as TransUnion, Ikea, Barclay’s bank and BP are among those to have introduced fitness trackers into their wellness schemes for tens of thousands of employees in the past couple of years. It's worth underlining that using the fitness trackers in these schemes is entirely voluntary, but those that sign up are encouraged to upload data from their devices to a computer system maintained by the company, where it is collated and used to tell employees how they are performing. 

But with all this sensitive personal data being collected and analysed by systems controlled by their employers, staff might be justified in worrying about how that information is used. 

Snooping?

“If you have an employee who is not performing well and is frequently absent, there could be a temptation to use the information from their fitness tracker to find out why,” warns Clare Gilroy Scott, an employment lawyer with Goodman Derrick. “An employee might say they are not well but an employer can see from the data recorded by their fitness tracker that they have done 14,000 steps that day. There are some big issues with these things.” 

In Europe, data protection laws prevent bosses from using data gathered about their employees in this way in any kind of disciplinary action, unless of course, they have previously informed their staff that they will, perhaps buried in a contract they signed when they joined the fitness programme.  

We are now seeing them being used in all sorts of industries - finance, oil and gas, even hospitals and universities – McDonough

“The data protection act requires employers to let their employees know if they might use their data in disciplinary actions," says Gilroy Scott. "And the employee would need to have consented. But if an employee is suggesting they are doing something they are not and an employer uses this fitness information as evidence to counter that, it could be more acceptable.”

So, this could mean that staff could still find their fitness data being used against them if they find themselves in a dispute with their employer. 

In the US, the rules are even less clear. Employees should be protected by discrimination laws that prevent employers from forcing workers to take part in wellness programmes or punishing those that do not. But technology analysts Gartner predict that by 2018 there could be as many as two million employees worldwide required to wear a fitness tracker as part of the terms of their employment.  

And many employers are now linking their fitness trackers to health insurance schemes, offering discounts to those who meet certain goals. UnitedHealthcare, for example, offers an employer programme that allows them to let their employees earn up to $1,500 a year (or $4 a day) in reimbursements on their health benefit plan if they reach daily walking goals while using an activity tracker. UnitedHealthcare said that while its Motion programme rewarded employees using fitness trackers, those who were unable to walk due to medical conditions could submit waiver forms. "Once the waiver has been approved, the employee will receive the full reward," explained a spokesperson for the company.

An employee might say they are not well but an employer can see from the data recorded by their fitness tracker that they have done 14,000 steps that day – Gilroy Scott

Some groups in the US - such as the AARP, formerly known as the American Association of Retired Persons, which represents older Americans - have challenged schemes like these on the basis that they could potentially discriminate against people who are less able to be active because of their age. 

Gilroy Scott also has concerns about the way many companies appear to be setting fitness goals for their employees in exchange for rewards. “If everyone has to get a certain number of steps to earn an extra day of leave, it could potentially be indirect discrimination,” she warns. “Older people and those with disabilities may be less able to reach those goals.” 

You don’t need to know what time I went to sleep or what I had for breakfast in the morning to run an effective wellness programme, but you might need to know step counts and the number of active minutes

Fitbit has published a pledge that it asks employers to make when they offer staff their trackers as part of a health scheme, including a statement that participation must be voluntary and cannot be used for adverse consequences or disciplining staff. McDonough admits, however, that they cannot force employers to fulfil this pledge, although the software platform it supplies offers some degree of protection. 

“Only a subset of the data is collected,” she says. “You don’t need to know what time I went to sleep or what I had for breakfast in the morning to run an effective wellness programme, but you might need to know step counts and the number of active minutes.” 

She adds that most employers tend to come to FitBit because they want to improve the health of their staff, encourage teamwork with competitions or improve employee safety by looking at aggregate sleep levels across the company. 

TransUnion, for example, has introduced challenges in to its scheme that put employees from its sites in different countries into teams to foster collaboration between international teams by encouraging them to work together to reach a goal. 

IBM also says it was extremely clear with the 50,000 employees who have signed up to its own scheme, which allows data from 15 different types of fitness tracker to be collated, about what would happen to their data. The data gathered from the devices is stripped of all identifying data before it is added to the system and then aggregated with the data from other employees before it is placed on the fitness "dashboard" on its intranet. This allows employees to check how they are performing compared to others, but without revealing who they are. 

 

“Wearable devices are really attractive to employers like ourselves because they give us a united theme to track activity across borders and hold cross country competitions,” says Ellen Exum, IBM's vice president of global health and wellness. 

IBM also provides its employees with an app that offers them mindfulness sessions or a nutrition app that offers personalised healthy eating programs and nutrition guidance. They are not alone - around 22% of companies also offer mindfulness training, according to one recent survey

This could, of course, be seen as a cynical ploy to make us all work harder. After all, a recent review of research into mindfulness found it could improve people’s performance at work and diet can also have a significant impact on your ability to work

Egg freezing

But there is another intervention in our health by employers that for some marks a distinct step way beyond the boundaries of where our work and personal lives intersect. Companies including Apple and Facebook are offering female employees financial support to freeze their eggs so that, if they choose to, they can use them later in life for fertility treatment. 

This controversial employee benefit offers female workers a way of potentially delaying when they might have children, giving them the opportunity to focus on their careers. There is, however, no guarantee that the expensive procedure - one that can costs tens of thousands of dollars and is also not without health risks - will lead to a baby for couples who have been unable to conceive naturally.

Apple says that its support for egg freezing is part of wider programme of policies it offers aimed at helping employees with their families, including extended maternity leave and assistance with some of the costs associated with adoption. A spokesperson for Apple said: "We want to empower women at Apple to do the best work of their lives as they care for loved ones and raise their families."

For Gateno, however, the direct involvement of his employer in his health has been a positive development in his life. It has given him a positive way of channelling his competitive spirit, but also left him feeling far healthier. 

“I weigh less now than I did when I graduated high school in 1992,” he chuckles.

To comment on this story or anything else you have seen on BBC Capital, please head over to our Facebook page or message us on Twitter.

If you liked this story, sign up for the weekly bbc.com features newsletter called "If You Only Read 6 Things This Week". A handpicked selection of stories from BBC Future, Culture, Capital and Travel, delivered to your inbox every Friday.