## 2 Materials and Methods
### Objective Assessment of Physical Activity  
For the purpose of objectively assessing participants' physical activity levels, the Actigraph GT3X accelerometer was selected as the measurement tool. This accelerometer, developed by ActiGraph LLC in Pensacola, FL, USA, is widely recognized and has undergone rigorous validation processes, ensuring its reliability in measuring physical activity. By utilizing this device, the researchers aimed to obtain accurate and trustworthy measurements of participants' physical activity behaviors.  
To facilitate precise and comprehensive data collection, the Actigraph GT3X accelerometer was positioned securely on the participant's right hip, attached to a waistband. This placement ensured that the accelerometer remained in a consistent and stable position throughout the study period, allowing for uninterrupted monitoring of physical activity. Participants were instructed to wear the device continuously for seven consecutive days, except during water-based activities.  
To ensure meticulous data capture, the Actigraph GT3X accelerometer was programmed to collect data at a sampling rate of 60 Hz. This high-frequency sampling provided detailed information about participants' movement patterns and physical activity levels throughout the entire day. By recording raw acceleration data in 60-s epochs, the researchers were able to capture the nuances and variations in participants' physical activity behaviors with greater precision. The cut-points used for classifying PA intensity were selected in accordance with the ActiLife software guidelines: light-intensity (200-2689 counts per minute), moderate-intensity (2690-6166 counts per minute), and vigorous-intensity (6167 and above counts per minute).  
The selection of the Actigraph GT3X accelerometer as the objective assessment method offered notable advantages over subjective self-report measures commonly used in previous studies. One significant advantage was the elimination of recall bias, which often affects self-reported data due to participants' imperfect memory of their physical activity. Additionally, this objective assessment method allowed for the accurate measurement of both the intensity and duration of participants' physical activities, providing a more comprehensive understanding of their actual engagement in physical activity.  
The portability and non-intrusiveness of the Actigraph GT3X accelerometer were crucial considerations in its selection. Its compact size and lightweight design ensured minimal interference with participants' daily routines, allowing for a natural and realistic representation of their physical activity behaviors. Participants were able to carry out their usual activities without significant disruptions while wearing the accelerometer, which enhanced the ecological validity of the study.  
In summary, the utilization of the Actigraph GT3X accelerometer in this study offered a robust and scientifically rigorous approach to objectively assess participants' physical activity levels. Its reliability, accuracy, and non-invasive nature made it an ideal tool for capturing precise data on participants' physical activity behaviors. This objective assessment method provided valuable insights into the actual engagement of participants in physical activities and contributed to a more comprehensive understanding of their physical activity patterns.