Is there a particular age group/demographic that interests you?

i hope this well help

http://omicsonline.org/using-social-cognitive-theory-to-predict-exercise-behavior-among-south-asian-college-students-2161-0711.1000155.pdf  

These could help

http://www.ncbi.nlm.nih.gov/pubmed/24666887

Hello Laura, You have several papers mentioning barriers and motivators for being physically active according to different demographic/age groups. If you are interested in the older population I would advise:

Baert, V., Gorus, E., Mets, T., Geerts, C., & Bautmans, I. (2011). Motivators and barriers for physical activity in the oldest old: a systematic review. Ageing Research Reviews, 10(4), 464–74. doi:10.1016/j.arr.2011.04.001

Costello, E., Kafchinski, M., Vrazel, J., & Sullivan, P. (2011). Motivators, barriers, and beliefs regarding physical activity in an older adult population. Journal of Geriatric Physical Therapy (2001), 34(3), 138–47. doi:10.1519/JPT.0b013e31820e0e71

I hope this helps!

Hello Laura, like the others already reported there are several articles and reviews on the barriers to and facilitators of exercise and sports participation of different populations (e.g. older population, children, youth, people with disabilities). However, you seem to be interested in articles on unsuccesful maintenance of exercising and physical activity.

If you are (also) interested in the population of people with physical disabilities I would advise those articles on the underlying mechanisms of decisions regarding behavior maintenance:

Fleig, L., Pomp, S., Schwarzer, R., & Lippke, S. (2013). Promoting Exercise Maintenance: How Interventions With Booster Sessions Improve Long-Term Rehabilitation Outcomes. Rehabilitation Psychology.

Luszczynska, A. and Sutton, S. (2006) Physical Activity After Cardiac Rehabilitation: Evidence That Different Types of Self-Efficacy Are Important in Maintainers and Relapsers. Rehabilitation Psychology. Vol. 51, No. 4, 314–321.

Dear Laura, one aspect of maintenance of physical activity belongs to environmental factors - which in my opinion are to rare mentioned. There are some interisting publications in the last years on this topic.

• Calogiuri G, Chroni S. (2014). The impact of the natural environment on the promotion of active living: An integrative systematic review. BMC Public Health. 2014; 14(1):873.
• Hobbs N, Godfrey A, Lara J, et al. (2013). Are behavioral interventions effective in increasing physical activity at 12 to 36 months in adults aged 55 to 70 years? A systematic review and meta-analysis. BMC Med. 2013; 11:75.
• McCormack GR, Rock M, Toohey AM, et al. (2010). Characteristics of urban parks associated with park use and physical activity: a review of qualitative research. Health Place. 2010; 16(4):712-26.

I am vewry sorry for not having a direct answer for you, but I am also interested in this from a personal point of view. You have tapped into the very nature of my life!! Is there any way you could share some articles of insight about this so I can work on this? Thanks.

Added to the previous information, you can find any paper about Burnout syndrome, which affect to active sportpeople and has shown an importante prevalence (1,5-5%)