There's no way around it: you're going to get hurt or even fragged running around the arena. You can tell how badly wounded you are by looking at the Health score displayed in the lower left portion of your HUD. At the start of every event, all gladiators begin with health scores of 125 (which counts down to 100). During the course of play, it's possible to increase your health beyond this value, although it will gradually count down to 100. Cross-shaped health bonuses are scattered throughout most arenas. Restore your health by running through them. After picking up health, it usually reappears 35 seconds later, becoming available for you again when you need to restock, however sometimes Megahealths are more scarce and take longer to respawn.