## 4 Implementation of the Mixed Prehabilitation Model
\begin{table}
\begin{tabular}{c c c c c c} \hline
**No.** & **Mode of Exercise** & **Intensity** & **Frequency (Hz)** & **Amplitude (m/s2)** & **Estimated Indicator for Measure of Intensity** \\ \hline \multirow{2}{*}{1} & \multirow{2}{*}{Walking (W)} & L & 1.5 & 15–32 & 4 km/h \\  & & M & 2 & 38–60 & 5 km/h \\  & & V & 2.25–2.5 & 45–75 & 6 km/h \\ \hline \multirow{2}{*}{2} & \multirow{2}{*}{Running (RU)} & L & 3 & 55–70 & 8 km/h \\  & & M & 3.25 & 55–75 & 10 km/h \\  & & V & NA & NA & NA \\ \hline \multirow{2}{*}{3} & \multirow{2}{*}{Treadmill (TM)} & L & 1.75 & 20–25 & 4.5 km/h \\  & & M & 2 & 45–55 & 5.5 km/h \\  & & V & 2.25 & 50–60 & 6.5 km/h \\ \hline \multirow{2}{*}{4} & \multirow{2}{*}{Cycling (C)} & L & 0.75–1 & 20–30 & 50 rpm \\  & & M & 1–1-25 & 30–55 & 70 rpm \\  & & V & 1.25–1.5 & 40–80 & 90 rpm \\ \hline \multirow{2}{*}{5} & \multirow{2}{*}{Cross-trainer (CT)} & L & 0.75-1 & 8–18 & 50 rpm \\  & & M & 1–1.25 & 20–28 & 70 rpm \\  & & V & 1.5 & 30–60 & 90 rpm \\ \hline \multirow{2}{*}{6} & \multirow{2}{*}{Rowing (RO)} & L & 0.25 & 4–6 & 50 Watt \\  & & M & 0.5 & 11–15 & 70 Watt \\  & & V & 0.75 & 18–26 & 100 Watt \\ \hline \multirow{2}{*}{7} & \multirow{2}{*}{Staircase ascension STRM} & L & 0.75 and 1.25 & 30–35 and 15–25 & No consistency in both F and A \\  & & Staircase descension & L & 0.75 and 1.5 & 20–30 and 15–25 & No consistency in both F and A \\ \hline \multirow{2}{*}{8} & \multirow{2}{*}{Step Ups (STP)} & L & 1.5 & 14–18 & 15 cm height \\  & & M & 1.5 & 20–25 & 20 cm height \\  & & V & 1.75 & 22–26 & 30 cm height \\ \hline \multirow{2}{*}{9} & \multirow{2}{*}{Leg Press (LEP)} & L & 0.25 & 5–6 & 90 kg, 20 times each session \\  & & M & 1–2 & 3–5 & 96 kg, 20 times each session \\  & & V & 0.5-3.75 & 0.5–5 & 115 kg, 20 times each session \\ \hline \end{tabular}
\end{table} 
Table 3: Results of frequency analysis of 3D accelerometer data for nine different types of activity at three different intensities collected from a sensor placed on the ankle of five participants (modified from [PERSON] et al. [12]). specific physical activity, as well as activity recognition, the time lapsed, and accumulation of credit points. Figure 1: The flow chart of the three methods of activity recognition. Figure 2: Amplitude and frequency data from different physical activities at different intensities over one hour. (**a**). amplitude of the dominant frequency, (**b**). frequency, (**c**). accumulated time, (**d**). accumulated gain. Specific activities and intensities are identified using amplitude and frequency extracted by the FFT analysis technique [12]. Equation (1) is applied to each pair of incoming data to calculate the credit gained during the session and then the output results are stored in a comma-separated value (CSV) file for further analysis. The results of three recognition methods are stored in a CSV file (Figure 2a,b) and a time stamp with the accumulated time and credit gain of each activity is shown in Figure 2c,d. The system displays the summary and stores the result in a CSV file each minute. In addition, new incoming data is stored in the same CSV file sequentially with a time stamp, regardless of the length of time between two sessions. Figure 2a,b illustrate FFT amplitude and frequency measures over one hour. During the first 15 min there are consistent frequency and amplitude data that identify the activity of cycling at a low (CL), moderate (CM), and vigorous (CV) intensity. Figure 2c,d display the accumulated credit data over one hour for the different physical activities at different intensities. The system stores the recognized activity, the period of each activity and the credit gain log file in real time. The system also summarizes the physical activities, exercise duration, and gained credit against each physical activity recorded over a 24-h period. Equations (1)-(3) calculate the total daily and weekly credits, respectively, while Equation (4) detects bed rest. Figure 3a illustrates six different exercises performed at light, moderate, and vigorous intensities.