Whether you sing the blues or not, a little extra happiness in winter won’t do any harm.

It’s no surprise that sport increases happy hormones as well as fitness, but West Virginia University scientists found joining a team increases all aspects of health satisfaction. If you train solo you’re five times more likely to have a poor perception of your health, according to the study. Avoid depression and illnesses by playing rugby once a week. Don’t fancy the bloody nose? Organise a running group with your friends.