I suppose I've mentioned willpower a couple of times here on WIP by now. To most people, willpower is something you have some in the morning and none by 4 pm, something that fills up during a good night's sleep and adds up to the same amount every morning. To most people it's something they have no control over.
So, to most people: I beg to differ!
Willpower can be increased, manipulated, charged during the day, and used to maximum advantage, not to mention having it long after 4 pm.
But first, let's get the basics straight. Willpower is like a battery - sleeping does indeed charge it, and if you sleep an adequate number of hours for you, the battery will be full when you wake up. That's why it's easiest to do unpleasant tasks right after you wake up; you'll have more willpower than in any other moment during the day and therefore the chances of completing the task are best.
If your day involves doing some kind of work - and for most people it does - willpower will decrease linearly with monotonous work, the rate depending on the type of work and individual attributes. The rate with which willpower is spent will increase if you go a long time feeling hunger, or if your blood sugar level drops, or if you exercise. Eventually the willpower battery will be empty, at which point you'll ditch all your principles regarding everything from dieting to work and will just watch Netflix and eat pizza (or whatever you consider to be easy, decadent, and enjoyable), because the empty battery has signaled your brain you have deserved it.
If you know the depletion of willpower may cause you problems described above, don't worry! You can recharge the battery during the day in more ways than one. Here are my tips for increasing willpower so you can think ahead and prevent potentially principle-wrecking moments during the day.
Take a nap. Napping gives you energy and charges your willpower much like a good night's sleep, only in a smaller scale. (Don't expect napping to charge your willpower batter completely.)
Eat either a good meal or a snack regularly, every few hours. This will keep your blood sugar levels steady so you won't find yourself neglecting work by daydreaming about that pizza. Beware meals and snacks that are heavy on carbohydrates, though, as they tend to make people sleepy.
Besides recharging the willpower supply by sleeping in the night and with the above tips during the day, the size of the battery itself can be increased. This means you'll go longer without food with no risk of falling for pizza. You can go to the gym after a long day at the office and go back to work after exercising. You can even do tedious tasks long after 4 pm! These will still use your willpower, but since the supply itself is bigger, you're free to use it as you please. To make your willpower battery larger, exercise willpower daily, even if a little bit and even if it's depleted already. It'll feel uncomfortable but it'll also teach your brain that it can do more. Continue doing this until you're happy with the amount of willpower you have at your disposal daily.
Or never stop increasing it - for what could be better than unlimited willpower?