Games for Health, 4(1), 43-52. Mary Ann Liebert Games for Health, 1, 4, 43-52 Games for Health Journal, 4(1), 43-52 Straker, L M, Fenner, A A, Howie, E K, Feltz, D L, Gray, C M, Lu, A S, Mueller, F, Simons, M & Barnett, L M 2015, ' Efficient and Effective Change Principles in Active Videogames ', Games for Health, vol. 4, no. 1, pp. 43-52 . https://doi.org/10.1089/g4h.2014.0077 Games for health journal, 4(1), 43. Mary Ann Liebert inc Games for Health Journal 4 (2015) 1