I would bet Lance Armstrong type cycle. Guy was great oly lifter but horrible stamina when he switched over. Then boom! It was as if he had twice the RBCs. Fucking beast either way and a true specimen of the species imo
Once reconstituted refrigeration will slow degradation. Refrigeration would be considered best practice but not necessary depending on how long it will sit before consumption.
Keeping it out of the light is equally if not more important