It of course depends on the outside temperature, but thermoregulation (warm-bloodines) in birds and mammals (and probably dinosaurs) is evolutionary trait even in not so cold environments. Muscles simply works better when warm. Some fishes (tuna maybe?) and dolphins uses somewhat complicated mechanism to keep the blood going through main muscles warm, even if the same blood is cold near the skin. If the animal is big enough it/he/she can use magazined heat (during the day of course).Tsukatta and Binter were probably equal in skill, training, and experience, making it a totally fair fight, but in the end Binter simply wore the human out. Vendari were reptillian and were actually cold-blooded, and that lent to them an endurance that no warm-blooded animal could match. Their metabolisms were able to pump all the energy into the muscles rather than trying to fuel a draining biological temperature regulating system.
Besides there are other evolutionary traits which can be/are used as a supply of energy (liver maybe ?).
The conclusion is that it is not as simple as cold-blooded creatures have more endurance because they did not need to spend the extra energy for thermoregulation: to keep the body warm and to keep the body (head mainly) from overheating.
