This is what some researchers from Moscow State University are proposing, according to Russia-InfoCenter. Neanderthals would have been actually specialist sprinters and that was what (allegedly) allowed them to hunt with heavy spears:
The ancient hunter could have crawled towards an animal as close as possible, and then had run as fast as he could, throwing a javelin, while running. However, a heavy spear is much more effective at small distances, than a light javelin. Calculations show that Neanderthal men had been able to cover 15-20 meters within 1-2 seconds, which is enough for a unexpected and successful attack. This means that Homo neanderthalensis were fast and accurate hunters, not clumsy snails as some may think.
Other details of their physiognomy are that they surely preferred to squat above sitting, because they lacked an intermediate layer of fat and muscle on their butts. They also got easily tired of long term standing, the researchers suggest.
Originally from Stone Pages' Archaeo News.