A new, insanely fast face unlock option is available for users who want facial recognition in their smartphone, and it works really well. (9to5google.com)
Your comment about how fast your face changed is SO accurate! (laurenhartmann.com)
I would change to doing 2 min fast face runs (maybe around 14 - 15 km / hr) instead of your current sprints. (rachaelattard.com)