Alongside the announcement that the Google Fit preview SDK is now available, Google snuck out new images for the Android L developer preview. The new images weigh in as build LPV81C and are still only available to the Nexus 5 and Nexus 7 (2013) WiFi.
Google has yet to add these to the Android L preview site as I write this post, so you will have to go through the Google Fit SDK page to grab them.
Go download ‘em! If you need instructions on how to flash factory images, hit up this post.