RODALE NEWS, EMMAUS, PA—When you’re faced with a difficult physical task, having the proper mindset can significantly increase your strength, suggests new research out of Harvard University. What’s more, it doesn’t take much to get you mentally into the zone. Doing good deeds, like a simple act of charity, seems to do the trick. But playing the role of the bad guy may have a similar effect.

THE DETAILS: The Harvard researchers conducted three separate experiments, with each one confirming their mind-over-matter hypothesis. In the first, 91 study participants were asked to hold a five-pound weight straight out from the body for as long as possible for a baseline measurement. The researchers then split the group into two. The first group was asked to donate $1 to the United Nations International Children’s Fund (UNICEF), which they all did willingly. The second group wasn’t asked about donating. Both groups were then asked to hold the weight again. Those who had donated held the weight an average of 53 seconds, or a full seven seconds longer than the non-donators.

In a second experiment, which involved different subjects, 151 people again held a five-pound weight as a baseline. They then were split into three groups. The researchers asked the first group—while holding the weight—to write a very short fictional story that had them helping someone. The second group, also while holding the weight, wrote about harming someone, and the third group wrote about neither helping nor harming someone. Turns out the do-gooders held the weight for five seconds longer than the neutrals, but the evildoers held it for eight seconds longer.

The researchers set up the final experiment exactly like the first, except they asked subjects to squeeze a hand grip rather than hold a weight. Sure enough, those who contributed $1 to UNICEF were able to squeeze the hand grip for 23 seconds longer than the non-donators.