This study examined the reasons GPs provided verbal advice for physical activity and administered Green Prescriptions. Both general verbal advice for physical activity and Green Prescriptions were administered for the same two reasons; either for preventive purposes or for management purposes. Green Prescriptions were administered as a form of primary prevention for patients who were currently disease free, but due to their weight (i.e., overweight or obese) were at risk for developing future health-related problems [20, 29, 30]. This finding is consistent with those from the annual New Zealand Sport and Recreation surveys which monitors Green Prescription utilization. These surveys have shown that Green Prescriptions are issued for weight management purposes more than for any other condition [31–33].
While GPs in the present study were administering Green Prescriptions or providing verbal advice for physical activity as a form of primary prevention for weight management purposes, they were not administering Green Prescriptions or verbally recommending physical activity for patients who were low-active or sedentary, but currently disease free and of average body weight. Sedentary individuals can benefit from a Green Prescription (or from verbal advice to become physically active), as they are currently disease free, but are at risk for future non-communicable diseases and conditions because of their inactive lifestyle [20, 30, 34].
It has been argued [20, 35] that some GPs believe that physical activity prescription or advice is likely to be more effective when it is linked to an existing chronic health condition. The Green Prescription is used more as a form of management for pre-existing conditions than as a form of prevention. However, low-active and sedentary individuals who are of normal body weight and are disease-free are not likely to see their GP on a regular basis, and thus, are less likely to be counselled for physical activity. This is one such example of a systemic barrier to implementation for GPs who administer Green Prescriptions.
A non medication approach to a healthier lifestyle was identified by GPs as being a salient benefit of the Green Prescription program, as patients did not encounter negative side effects that drug use entails. GPs discussed how in the eyes of patients a Green Prescription validates the importance of physical activity as a treatment for health gain. This was related to physical activity advice being provided by a medical professional. Such a view is consistent with the research demonstrating that some groups of individuals are more likely to consider and adhere to physical activity advice when it is imparted by their GP [22, 36].
A Green Prescription also validates the importance of physical activity as a treatment for health gain as it presented in a prescription format like pharmaceutical treatment. Research shows that the Green Prescription format can be understood by many individuals, because the use of a prescription is a well understood interaction between doctor and patient [17, 19]. Prescriptions are viewed by individuals as being sources of medical help, with a written prescription for physical activity also acting as a tangible reminder for the patient to engage in activity [17, 19, 37].
The prolonged and specialised support that patients receive from the Green Prescription patient support counsellor was identified by GPs as being another benefit of the Green Prescription program. This finding is important as previous research has not specifically focused on the aspects of the Green Prescription program that GPs believe best facilitate ongoing physical activity in their patients. In annual Sport and Recreation Green Prescription surveys, patients have stated that the advice, support, and encouragement that they have received from their patient support counsellor has helped to keep them active and complete their Green Prescription [30, 38]. The GPs views on the importance of the patient support counsellor is also consistent with the results of a qualitative study investigating patients' views and experiences of receiving a Green Prescription . Some patients in the Elley et al.  study viewed their patient support counsellor as a "significant other" - someone who had some influence over their behaviour. For example, some patients felt motivated to comply with their Green Prescription because of the ongoing telephone support they received from their patient support counsellor.
Time constraints of the consultation were cited as the most salient barrier to Green Prescription use by GPs, a finding consistent with that of earlier studies [37, 35]. The present study is one of a few studies that have specifically examined how New Zealand GPs have dealt with their perceived barriers of the Green Prescription program. One GP mentioned that she delegated the more time consuming tasks, such as choosing an activity, to the Green Prescription patient support counsellor. In some practices, practice nurses also assisted in the administering of Green Prescriptions. These two methods to reduce time demands are important given that both New Zealand and international literature consistently cites time constraints as GPs' most salient barrier to physical activity counselling [35, 37, 39–41]. There is some evidence to suggest that in some cases it can be less time consuming for a GP to outline the Green Prescription program and administer a Green Prescription than to start a patient on a new medication . If further studies can replicate the findings of Wyndard , it is hoped that even more GPs will see the promotion of the Green Prescription as a time-efficient and beneficial intervention for many of their patients.
This is the first New Zealand based study that has examined GPs views on the role that the Green Prescription program can have in helping manage depression. In the present study, all GPs viewed physical activity engagement in general, as well as prescribed physical activity through the Green Prescription program as beneficial for the management of depression. GPs stressed that this was related to the release of natural mood enhancing chemicals (e.g., endorphins). Some GPs discussed how they use Green Prescription counselling in conjunction with antidepressant medication. This combined treatment mode has been studied in randomised controlled trials [43, 44]. One study  found physical activity to be just as effective as antidepressant medication in decreasing depressive symptomatology over the course of the 16-week intervention period in individuals who had a clinical diagnosis of depression. However, this study did not have a follow-up period to ascertain the long-term effect that physical activity had on depressive symptomatology.
A growing body of research has demonstrated that some degree of regular physical activity or exercise can lower depressive symptomatology in adults who have a clinical diagnosis of depression [9–11, 43–47]. Physical activity interventions may be more beneficial in the management of depression for some groups of individuals (i.e., older adults) compared to antidepressant medication . Physical activity interventions are less likely to have adverse 'side effects' and can be undertaken on a regular, long-term basis. Compared to drug treatment, there is also no negative stigma attached to engaging in regular physical activity .
Strengths and Limitations
A main strength of this study is that a qualitative methodology was employed to allow GPs to voice their views and experiences of counselling for physical activity in general, and more specifically, through the Green Prescription program. This allowed a range of issues to be discussed and themes to be derived from the data. A potential limitation of this study was the relatively small number of GPs interviewed. Thus, generalising findings to the larger GP population may be problematic. Also, participation in this study was voluntary. Potential participants were mailed a letter of invitation that outlined the main aims of the study. Although it is likely that GPs who administered Green Prescriptions and/or gave verbal advice for physical activity would be more interested in participating in this study than GPs who did not, the sample interviewed was diverse in this respect.