. 2015 Sep 18;10(9):e0138218. doi: 10.1371/journal.pone.0138218
© 2015 Hardcastle et al
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
Fig 5. Exercising with others: a source of motivation.
