Not only intriguing from the common aspects of laughter and exercise, some interesting observations about how the beneficial impact increases in group situations. Quote:
Why the interplay of endorphins and laughing should be of interest to those of us who exercise may not be immediately obvious. But as Dr. Dunbar points out, what happens during one type of physical exertion probably happens in others. Laughter is an intensely infectious activity. In this study, people laughed more readily and lustily when they watched the comic videos as a group than when they watched them individually, and their pain thresholds, concomitantly, rose higher after group viewing.
Something similar may happen when people exercise together, Dr. Dunbar says. In an experiment from 2009, he and his colleagues studied a group of elite Oxford rowers, asking them to work out either on isolated rowing machines, separated from one another in a gym, or on a machine that simulated full, synchronized crew rowing. In that case, the rowers were exerting themselves in synchrony, as a united group.