"Laughter yoga" may be silly, but according to this study, it's a serious ab workout.

They say that laughter is the best medicine. And these days, who wouldn't benefit from a good laugh? Well, according to this study, your abs also benefit from laughing, even if that laughter is gotten by seemingly artificial means: laughter yoga. Honestly, if this youtube video is at all representative of a laughter yoga session, it looks pretty awesome. And it's even a better ab workout than traditional crunches. WIN! [embed]http://www.youtube.com/watch?v=lGNOF8DVIPQ[/embed] Laughing: a demanding exercise for trunk muscles. "Social, psychological, and physiological studies have provided evidence indicating that laughter imposes an increased demand on trunk muscles. It was the aim of this study to quantify the activation of trunk muscles during laughter yoga in comparison with crunch and back lifting exercises regarding the mean trunk muscle activity. Muscular activity during laughter yoga exercises was measured by surface electromyography of 5 trunk muscles. The activation level of internal oblique muscle during laughter yoga is higher compared to the traditional exercises. The multifidus, erector spinae, and rectus abdominis muscles were nearly half activated during laughter yoga, while the activation of the external oblique muscle was comparable with the crunch and back lifting exercises. Our results indicate that laughter yoga has a positive effect on trunk muscle activation. Thus, laughter seems to be a good activator of trunk muscles, but further research is required whether laughter yoga is a good exercise to improve neuromuscular recruitment patterns for spine stability." Related content: Dying with laughter…literally.Presidential laugh lines. Candidate display behavior and audience laughter in the 2008 primary debates.Rectal salami.