Willpower is like a muscle that depletes when it is exercised. Similarly, our ability to make high quality decisions becomes fatigued over time. The more decisions you make, the lower quality they become — the weaker your willpower.
A 2007 research study found that taking cold showers routinely can help treat depression symptoms often more effectively than prescription medications. That’s because cold water triggers a wave of mood-boosting neurochemicals which make you feel happy.