Setting and Time of the Study The data were collected in the Cardiology Outpatient Clinic of X State Hospital and Y State Hospital between February and June 2022.

Population and Sample of the Study The study population consisted of patients who were receiving outpatient care at the Cardiology Outpatient Clinic of X State Hospital and Y State Hospital and had experienced a myocardial infarction (MI) at least three months ago. To determine the appropriate sample size, a power analysis was conducted using the G\*Power 3.1.9.6 program based on a previous study (23) involving MI patients. The power analysis resulted in a sample size of 34 patients in total, with 17 patients allocated to each group. This sample size was determined to achieve 80% power, an effect size of 0.87, and a margin of error of 5%. However, considering that increasing the sample size would decrease the standard error and increase the study power (24), each group was increased by 75%. As a result, a total of 60 patients, with 30 patients in each group, were included in the study. For practical reasons (geographical location, working conditions, and limited availability of myocardial infarction (MI) patients), a total of 30 MI patients who were being treated as outpatients at the Cardiology Outpatient Clinic of Y State Hospital and had experienced MI at least three months prior were assigned to the experimental group. Another 30 MI patients who were being followed up as outpatients at the Cardiology Outpatient Clinic of X State Hospital and had also experienced MI at least three months before were assigned to the control group using criterion sampling. Criterion sampling involves selecting individuals based on predetermined criteria or qualifications for the study's objectives. It is important to note that in this study, the assignment of patients into groups was not done through randomization or matching. However, statistical analyses of the descriptive and disease-related information of the patients indicated no significant differences between the groups. This outcome confirms that the descriptive and disease-related characteristics of the groups were similar, thereby achieving an equal and homogeneous distribution in the study.

Green Walk Group Patients who were admitted to the Cardiology Outpatient Clinic of Y State Hospital and passed the six-minute walk test (6MWT) conducted by the cardiology physician were eligible for participation in the green walk group. Following the physician's examination at the Cardiology Outpatient Clinic, the researcher conducted face-to-face interviews with the patients in a private room. During these interviews, the patients were administered the Structured Patient Information Form, Blood Lipids and BMI Monitoring Form, the Brief IPQ, and the MIDAS, and the collected data were recorded on the respective forms. Then, the researcher provided detailed information to the patients about green walking. For the randomized MI patients, two groups were formed, and they engaged in a 50-minute green walking three days a week for 12 weeks, under the guidance of the researcher. The green walk group's walks were scheduled differently for the two subgroups. The first subgroup had their 50-minute walk on Monday, Wednesday, and Saturday, while the second subgroup had their walks on Tuesday, Thursday, and Sunday. This arrangement ensured a standardized time interval between green walks for both groups. Additionally, a follow-up Blood Lipids and BMI Monitoring Form was administered to the patients during their visit to the Cardiology Polyclinic in the middle of the study (6th week). At the end of the 12-week period, the patients in the green walk group underwent a posttest evaluation.

Control Group: Patients who were admitted to the Cardiology Outpatient Clinic of X State Hospital and passed the 6MWT conducted by the cardiology physician were enrolled in the control group. Upon their visit to the outpatient clinic, the patients in this group underwent a face-to-face interview, during which they were administered the "Structured Patient Information Form," the "Blood Lipids and BMI Monitoring Form," the "Brief-IPQ," and the "MIDAS" as pretests. The information and data collected from these interviews were recorded on the respective forms. The patients in the control group continued with their routine daily activities. No specific intervention or additional measures were implemented by the investigator in this group. Furthermore, a follow-up "Blood Lipids and BMI Monitoring Form" was administered to the patients during their visit to the Cardiology Outpatient Clinic in the middle of the study (6th week). At the end of the 12-week period, the patients in the control group underwent a posttest.