*3.1. Data Acquisition*

This study was based on the data previously acquired for the study [20], which consists on the acquisition of data related to five ADLs, such as standing (Figure 2), walking (Figure 3), running (Figure 4), walking upstairs (Figure 5), and walking downstairs (Figure 6). The data used for this study are available in a public repository [65] previously used in [20]. A visual presentation of the data collected in each activity is presented in Figures 2–6.

**Figure 2.** Acceleration (m/s2)—five seconds of data collected during the activity of standing.

**Figure 6.** Acceleration (m/s2)—five seconds of data collected during the activity of walking downstairs.

The dataset comprehends more than 2000 samples with five seconds of accelerometer data for each ADL. A mobile device placed on the front pocket of the user's pants was used for data acquisition. The data were acquired in a controlled environment, where, before the start of the data collection, the user had to select the ADLs that he/she would perform. Every five seconds of data were acquired every five minutes. When the user planed to perform another ADLs, he/she should stop the data collection and change the ADLs selected in the mobile application used.

Twenty-five individuals were selected for the experiments that always used the same mobile device; i.e., an *BQ Aquaris 5.7* smartphone [66]. These individuals were aged between 16 and 60 years old, composed of five teenagers and five people between 40 and 60 years old, and the remaining were randomly selected. Several environmental constraints were uncontrolled during the data acquisition, but we had control of the procedures related to the labeling of the different samples and the positioning of the device. As we acquired five seconds of data every five minutes, the individuals spent around 7 h performing each ADL collected by the mobile device. In total, each individual spent around 35 h for the data acquisition.
