From analysis of a mass grave near Ephesus it appears that Roman gladiators were vegans. Their bone samples were very high in strontium and low in zinc - an indication of vegetarianism – and, according to forensic anthropologist Karl Grossschmidt, their diet was exclusively barley and beans (as well as a bit of dry ash, which was supposed to add muscle). He thinks the diet was supposed to bulk them up so that the layer of fat would supplement their armour. Gladiators were colloquially called hordearii (‘barley-men’) and depicted in mosaics as quite stocky. Contrary to the vegetarian stereotype, though, it appears that they did not wearals but went barefoot, as evidenced by bone enlargement in the feet.
Just look at the gladiators... Consider how they who have been well-disciplined prefer to accept a blow than ignominiously avoid it! How often it is made clear that they consider nothing other than the satisfaction of their master or the people!
Gladiators are named after their gladius, which was a small, flattish sword.
A wooden sword was the symbol of a gladiator's retirement and freedom.
There’s no evidence for the belief that Roman gladiators ever said Morituri te salutamus or Morituri te salutant ('We (or "those") who are about to die salute you'). The phrase is only cited in two different accounts of the same event by Suetonius and Cassius Dio, which was not a gladiatorial contest.
The event in question took place in ad 52. The Emperor Claudius drained Lake Fucinus in the central Appennines in order to protect the surrounding district from floods and to reclaim the area for agriculture. But before doing so he staged a naumachia, a mock naval battle. However, the performers were prisoners under sentence of death, not gladiators (a naumachia was a spectacular form of execution, a battle fought until all the participants were killed). Suetonius says: 'When the fighters shouted the words Ave imperator, morituri te salutant, Claudius answered: Aut non; after which statement, as though he had pardoned them, they all refused to fight.' The historian goes on to state that Claudius went into a tantrum, threatening to destroy them all with fire and sword, jumping from his seat and dashing around the lake, and alternately shrieking threats and imploring them to go on with the fight.
The remark seems to reflect the condemned status of these naumachiarii, and there’s no evidence that it was in regular use even by naumachiarii, or that it was ever used by gladiators.
When a gladiator had been wounded and wished to concede defeat, he would hold up an index finger. At this point the crowd would indicate with gestures whether they wished the defeated gladiator to be killed or spared. The popular belief (illustrated in Pollice Verso, an 1872 painting by Jean-Léon Gérôme) is that 'thumbs down' meant death and 'thumbs up' meant a pardon, but we have no visual evidence for this, and the written evidence states that pollicem vertere ('to turn the thumb') meant death and pollicem premere ('to press the thumb') meant a pardon. This may, in fact, indicate that those who wanted the gladiator killed waved their thumbs in any direction, and those who wanted him spared kept their thumbs pressed against their hands.
Slaves would prod fallen gladiators with red-hot irons to make sure they weren't just pretending to be dead.
Gladiators sometimes formed trade unions.