I stopped my ride and I wanted to charge my Edge 530. I don't know why and what happened but it saved my ride, even though I did not want this to happen. Thank you!
AFAIK there is no official way to suspend activity and continue it later on edge devices. Sporadically device can restore activity after shutdown, but sometimes it simply ends/saves ride. In particular, it always ends ride when device is connected via USB using data transferring.