Treat the poker tournament like a job. Live tournaments and online majors can be huge grinds. Were talking anywhere between 8 and 20 hours, depending on the structure of the tournament. Being able to stay focused for such a lengthy period of time will require you to be on point at all times. Keep your distractions to a minimum. Live, try to only take bathroom breaks and meals or snacks during the allotted break times given during the tournament.
Eating a meal at the table or running to take a leak may not seem like a huge deal, but that salad you picked up to munch on will require your attention for the 10-15 minutes it takes to scarf down. When at the table, you should be focused on poker and poker only; I dont even recommend music players at the tables anymore, unless its something you must have to keep a clear head with. Online, try to keep only poker related things up on your desktop; no facebook, no downloading movies, etc. The less outside sources you have clogging up your mind, the more focused you can be for a grueling day.
Keeping the flow. Youre probably used to high and low points during your runs playing poker; big suckouts, massive pots, and the like. If you allow the adrenaline of those moments to flood through you every single time they happen, youll grind down well before the end of the day, and quickly lose energy and focus that are vital to the late day endgame.
Keep everything in check; whether you win or lose big, treat like another hand as much as possible. Youll find your tilt factor will decrease significantly by approaching the game that way, which also helps make it through the day. The less energy you expend celebrating, mouthing off, or cursing, the more you have to analyze, number crunch, and study.
Meal/Drink Selection. If youre a smoker, firstly, that habit will come back to haunt you in live tournaments. Most of them feature two hour intervals between breaks, so unless you feel inclined to dash in and out of the poker room between hands, youre probably going to have to deal with no cigarettes. Your meals and snacks should be enough to keep you sated, but not so much that youre bogged down and weary after the dinner break.
Think salads, light sandwiches, veggie plates, pastas, and so forth. Greasy foods and red meat are generally the type of foods that will wear you down after eating them, so skip them if possible. Alcohol is an absolute no-no, as well as energy drinks; stick with water and juice as much as possible. This isnt a suggestion to go on a diet; these are the type of fuels that will allow you to tread through the long days you have ahead of you without missing a beat at the tables.