Measuring enjoyment of physical activity in older adults: invariance of the physical activity enjoyment scale (paces) across groups and time

Sean P Mullen, Erin A Olson, Siobhan M Phillips, Amanda N Szabo, Thomas R Wójcicki, Emily L Mailey, Neha P Gothe, Jason T Fanning, Arthur F Kramer, Edward McAuley
International Journal of Behavioral Nutrition and Physical Activity 2011, 8:103 (27 September 2011)