Thinking about doing evil makes you stronger

... Gray's findings are based on two studies. In the first, participants were given a dollar and told either to keep it or to donate it to charity; they were then asked to hold up a 5 lb. weight for as long as they could. Those who donated to charity could hold the weight up for almost 10 seconds longer, on average.

In a second study, participants held a weight while writing fictional stories of themselves either helping another, harming another, or doing something that had no impact on others. As before, those who thought about doing good were significantly stronger than those whose actions didn't benefit other people.

But surprisingly, the would-be malefactors were even stronger than those who envisioned doing good deeds.

"Whether you're saintly or nefarious, there seems to be power in moral events," Gray says. "People often look at others who do great or evil deeds and think, 'I could never do that' or 'I wouldn't have the strength to do that.' But in fact, this research suggests that physical strength may be an effect, not a cause, of moral acts."

via Being naughty or nice may boost willpower, physical endurance.