New trademark filings released today suggest that Fitbit is going to update its Charge and Flex wearables. The trademarks cover the Fitbit Charge 2 and the Fitbit Flex 2, marking the first upgrades to the devices since they were released in 2014 and 2013, respectively. Fitbit already released two new products this year — the Blaze and the Alta — both of which were on the higher end of its offerings. Four products in one year? Does filing trademarks burn calories? If so, how many?