Ride your bike
Most enduros are roughly two to four hours long. If you have signed up for your first enduro, get some practice in and ride your bike in the lead up. The fitter and healthier you are, the more fun you will have on the bike because you will have the ability to enjoy it, rather than just surviving the day. Get out for at least one or two rides a week on your mountain bike in the weeks or months leading up to the event. As well as dialing your body in, the practice also gives you the chance to see how your bike is working and the possibility to try some different tires to help your performance.