I'd happily cease to participate in working there if that happened to me.

Unfortunately in the US, the lack of good health insurance options in spite of Affordable Care Act (ACA) means that even after paying the penalty for opting out of soul-crushing health tracking, it is probably still cheaper to work for a company for a company-subsidized health plan than to pay for it all oneself :(.

I'm unfamiliar with these programs. What does participation entail?

For mine, participation entails a yearly health screening. The screening measures blood pressure, BMI, nicotine usage, and cholesterol (via a blood draw).

Depending on the findings, you fall into 1 of 3 tiers, which results in a penalty on every pay check if you don't fall into the numbers.

I know someone who works for Blizzard; if they wear a Fitbit and meet the goal set on it, they get a healthcare discount or a small cash kickback, I forget which.

Found a detailed presentation of the incentive plan here: http://www.myablife.com/files/HIP-Presentation.pdf