>>128884
>short
It can be just your muscles man. Some body types lend themselves excellently to endurance sports, while others are more power-based. Lanklets often have 'long' wrong word but i dont know the english variant muscles, which train easier in endurance while vice versa with manlets.
You will need to train far more to get even an average endurance, but I believe that if you put your mind to it, you will make it.