BackgroundAccurate information is lacking on the extent of transportation as a source of physical activity, on the physical activity gains from public transportation use, and on the extent to which population shifts in the use of transportation modes could increase the percentage of people reaching official physical activity recommendations.MethodsIn 2012–2013, 234 participants of the RECORD GPS Study (French Paris region, median age = 58) wore a portable GPS receiver and an accelerometer for 7 consecutive days and completed a 7-day GPS-based mobility survey (participation rate = 57.1%). Information on transportation modes and accelerometry data aggregated at the trip level [number of steps taken, energy expended, moderate to vigorous physical activity (MVPA), and sedentary time] were available for 7,644 trips. Associations between transportation modes and accelerometer-derived physical activity were estimated at the trip level with multilevel linear models.ResultsParticipants spent a median of 1 h 58 min per day in transportation (8.2% of total time). Thirty-eight per-cent of steps taken, 31% of energy expended, and 33% of MVPA over 7 days were attributable to transportation. Walking and biking trips but also public transportation trips with all four transit modes examined were associated with greater steps, MVPA, and energy expenditure when compared to trips by personal motorized vehicle. Two simulated scenarios, implying a shift of approximately 14% and 33% of all motorized trips to public transportation or walking, were associated with a predicted 6 point and 13 point increase in the percentage of participants achieving the current physical activity recommendation.ConclusionsCollecting data with GPS receivers, accelerometers, and a GPS-based electronic mobility survey of activities and transportation modes allowed us to investigate relationships between transportation modes and physical activity at the trip level. Our findings suggest that an increase in active transportation participation and public transportation use may have substantial impacts on the percentage of people achieving physical activity recommendations.Electronic supplementary materialThe online version of this article (doi:10.1186/s12966-014-0124-x) contains supplementary material, which is available to authorized users.

The aim of this study was to test whether the effect of the pile-up of demands associated with a disability on quality of One of the core notions in the systemic approach is that families form an interactive and interdependent system where what happens to one family member will also affect all the other members of the system (Goldenberg & Goldenberg, 2003;Turnbull & Turnbull, 2001). The disability of a child is such an event that will affect the whole family. Compared to families with typically developing children, a child with a disability poses specific challenges. A multitude of adverse effects of a disability on the family have been found, including higher levels of stress, lower well-being, more negative feelings on parenting, less marital satisfaction, a financial and a caretaker burden (Baker, Blacher, & Olsson, 2005;Blacher & McIntyre, 2006;Hatton & Emerson, 2003;Hunfeld et al., 2001;Maes, Broekman, Dosen, & Nauts, 2003;McIntyre, Blacher, & Baker, 2002;Wilkinson et al., 2001).However, research in families with a child with a disability is inconclusive regarding the impact of the disability on the family. Other studies in families of children with a disability recognize the positive effects these children can have on their family members, including better parent-child interactions, more family cohesion and a stronger life purpose Quality of Life 4 (Flaherty & Glidden, 2000;Glidden, Bamberger, Turek, & Hill, 2010;Green, 2007; Hastings & Taunt, 2002;Kearney & Griffin, 2001;Taanila, Jarvelin, & Kokkonen, 1999). Thus some families seem to do well despite the extra stressor of the disability of their child, while others struggle and succumb.There is a large body of literature suggesting several individual and family characteristics that are positively related to the family's adaptation to a child with a disability. Social support, resilience, good family cohesion, effective coping skills and positive cognitive appraisals might all influence the potential negative impact of the disability on the family (Lavee, Hamilton, & Patterson, 1985;Saloviita, Itälinna, & Leinonen, 2003;Taanila et al., 1999;Tak & McCubbin, 2002).It has become apparent that individual and family outcomes due to the impact of a pile-up of demands associated with living with a disability are the result of multiple factors interacting with each other. Therefore a multivariate model incorporating both psychological and social variables that could intervene between the stressor and the outcome is needed. The double ABCX model of McCubbin and Patterson (1983) is one of the most influential theoretical frameworks in this field. The model provides a theoretical basis for examining the effect of a stressor and pile-up of demands (factor aA) on the family adaptation (factor XX) through the Quality of Life 5 mediation of the existing and expanding family recourses (factor bB), the meaning the family assigns to their situation (factor cC), and the coping strategies employed by the family (factor BC) (Jacques, 2006;McCubbin & Patterson, 1983), w...