Standards varied over time, but normally recruits were first required to complete 20 Roman miles (29.62 km or 18.405 modern miles) with 20.5 kg in five summer hours (the Roman day was divided into 12 hours regardless of season, as was the night), which was known as "the regular step" or "military pace". They then progressed to the "faster step" or "full pace" and were required to complete 24 Roman miles (35.544 km or 22.086 modern miles) in five summer hours loaded with 20.5 kilograms (45 lb). The typical conditioning regime also included gymnastics and swimming to build physical strength and fitness. After conditioning, the recruits underwent weapons training; this was deemed of such importance that weapons instructors generally received double rations. Legionaries were trained to thrust with their "gladii" because they could defend themselves behind their large shields ("scuta") while stabbing the enemy. These training exercises began with thrusting a wooden "gladius" and throwing wooden "pila" into a quintain (wooden dummy or stake) while wearing full armor. Their wooden swords and "pila" were designed to be twice as heavy as their metal counterparts so that the soldiers could wield a true "gladius" with ease. Next, soldiers progressed to "armatura", a term for sparring that was also used to describe the similar one-on-one training of gladiators. Unlike earlier training, the wooden weapons used for "armatura" were the same weight as the weapons they emulated. Vegetius notes that roofed halls were built to allow for these drills to continue throughout the winter. Other training exercises taught the legionary to obey commands and assume battle formations. At the end of training the legionary had to swear an oath of loyalty to the SPQR (, the senate and the Roman people) or later to the emperor. The soldier was then given a diploma and sent off to fight for his living and the glory and honour of Rome. Once the soldier had finished his training he was typically assigned to a legion, the basic mass fighting force. The legion was split into ten sub-units called cohorts, roughly comparable to a modern infantry battalion. The cohorts were further sub-divided into three "maniples", which in turn were split into two centuries of about 80–100 men each. The first cohort in a legion was usually the strongest, with the fullest personnel complement and with the most skilled, experienced men.