Exercising can be a lonely business, but it probably shouldn't be.
A study done at Oxford University shows that training in a synchronized group heightens tolerance for pain, enabling members of the group to train longer and harder.
The key to this effect seems to be the release of endorphins in the brain. Endorphins make us feel good, helping us work harder. You know the saying: no pain, no gain.
The authors of the study compared the pain thresholds of competitive rowers as individuals and as part of a team in order to study the group effect.
Ideally, any group activity should produce the same benefits. Aerobics devotees and spinning class groups already know this.
But loner types might try inviting friends along for the next power walk or pool workout. You may find that pushing the envelope is easier with friends along to help you pump out those endorphins.