The strategy: gamble his grief away
The verdict: skip it
Sad people are willing to spend almost four times more money than those who aren't blue, according to a 2008 study in Psychological Science. And that's dangerous for your friend. UCLA research found that if a man feels like he's out of control, it'll take him longer to recover from heartbreak. Go ahead, plan a trip that'll put some physical distance between him and her - just choose an outing that won't tempt him to empty his wallet.

The strategy: surround him with women
The verdict: do it
Men who've been dumped worry that they'll have a hard time finding another partner, according to a 2008 study in the journal Evolutionary Psychology. "The more options he has, the better he'll feel about his future prospects," says Carin Perilloux, a psychologist at the University of Texas at Austin. Take him where the women are, like parties where the men are seriously outnumbered.

The strategy: give him a shoulder to cry on
The verdict: skip it
When people relive the sadness of a breakup, they tend to stay stuck in a rut of negative emotion, say researchers from Columbia University in the US and the University of California at Berkeley. So if he starts to wallow in weepy mode, remind him of all the times she pissed him off - a 2006 study published in the journal Emotion shows that heartbroken people move on faster when they're angry at their exes.

The strategy: distract him with exercise
The verdict: do it
Join a gym together, sign up for an indoor football league, or begin training for a half-marathon. Whatever you choose, he'll have something to look forward to in his downtime - downtime he used to spend with his ex. Regular exercise will also cause his brain to pump out more mood-boosting chemicals. Bonus: "Working out will make him feel more attractive to women," says Perilloux.