Actual Google app: https://www.wareable.com/media/images/2017/03/google-fit-app... WTF Google?
OP's design is much nicer than this. Maybe the "3-5 hours" requirement was hinting that it needed to be as "material design generic" as possible. Which, this design clearly does.
Google's app tends towards the bland, but I don't think OP's designs are a huge improvement.
Also OP's app is targeting the gym nut. Google's is targeting the average person who is looking to just do any type of physical activity.