Marketers would have a field day with that data.
"This guy had increased heart rate followed by two minutes of physical activity... Joe, call Pfizer immediately!"
Accelerometers and GPS would allow them to narrow down specific types and patterns of sex as well. Lots of sex in cheap motels == high risk. Correlating customers together..this one has HIV, and appears to be having sex with this customer == high risk. Fun.
This is not about some extra win-win motivation to be healthier...
It's about turning risk (which is supposed to be what insurance companies are paid for) into rent-seeking...
Although you get rewards from them (Starbucks drinks, cinema tickets, etc.) rather than straight discounts on your insurance.