A sea turtle pushes water back with its
Flippers, but its body moves forward.
what law ?

Reptiles are ectothermic, meaning they rely on the environment to regulate their body temperature, and sea turtles are no exception. It is therefore surprising that unlike other sea turtles, leatherbacks are cold-adapted. They can migrate to cold water to hunt their prey without getting cold-stunned. The leatherback achieves this feat with counter-current heat exchange. This system runs warm blood from their inner bodies out to their extremities next to the cold blood running back inwards. The two blood temperatures participate in heat exchange and, therefore, the cold blood is warmed before re-entering the body core. Leatherbacks also retain warmth because of their dark color and layers of fatty tissue and oil that act as heat absorbers and insulation. The leatherback has a much higher metabolism than other sea turtles; their huge muscles create a lot of heat when they are active.

muscle endurance

explanation:

i can do 50 in a row ( but i get so tired after that)

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.