## 2 Materials and Methods  
The study was conducted in accordance with the Helsinki Declaration. Every participant provided written consent after being informed about the aim, protocol, and methodology of the study. The Bioethics Committee of the University approved the research project. Health interviews were conducted before vibration training among volunteers. The participants in this study were women over 50 years of age. They were either excluded from the study or qualified for one of the two vibration programs offered by the equipment: the disbalance program (D) or the osteoporosis program (O). Inclusion criteria were completion of the participation agreement, being over 50 years old, and having the ability to move without support. The D program was intended for women with little or no health problems, while the O program was for women whose health issues were assessed as a medium risk. Exclusion criteria were acute inflammations, fresh surgical wounds, serious injuries, thrombosis, cancer, severe arthritis, advanced discopathy, severe pain (especially in a knee, hip joint, or spine), heart pacemaker, severe arrhythmia, severe coronary heart disease, serious unregulated hypertension, retinal detachment, nausea and malaise, and dizziness. Forty-two women were trained on the D program (7-9 vibration series, lasting 45-60 s each), and 23 women on the O program (9-11 vibration series, lasting 50-60 s each). Of these women, 12% did not complete the study protocols due to health problems (Table 1). SR-WBV training was performed using the SRT Zeptor(r) Medical-plus noise device (Figure 1). This device consists of two plates emitting vibrations of varied direction and power. During training, a volunteer would put both feet (without shoes) on the plates of the device and stand straight with slightly bent knees. After running a selected program, plate units started to move in a disorganized way, gradually increasing in frequency and amplitude, until the desired intensity had been reached. The participant was relaxed, with their torso and head remaining as calm as possible. During a break between series of vibrations, the participant could maintain any comfortable position. The vibration frequency ranged from 2 to 8 Hz. The vibration amplitude ranged from 0.5 to 3.5 mm. In the D program, depending on the level, there were 7 to 9 vibration series that lasted 50 to 60 s each, and, in the O program, there were 9 to 11 series that lasted 50 to 60 s each, with 40 to 60 s breaks between series. In the O program, compared to the D program, vibrations were noticed less by the women due to a lower vibration amplitude and a different type of imposed stochastic noise. The first training session was always performed using a low or medium level of vibrations. If women did not report negative feelings after the first session and gave their consent, the vibration level was raised during the next sessions. At the low and medium level, the maximum vibration frequency is 6 Hz, and at the high level, it is 8 Hz. During each training session, the weakest vibrations characterized the first and last series, while the middle ones were the strongest. Depending on the programs and vibration levels used, each training session lasted between 10 and 22 min. A full cycle of vibrations consisted of 12 sessions, two times a week, with at least a one-day break between sessions. The entire study lasted six weeks. A more detailed description of training programs is provided in Supplement 1. Detailed information about the number of participants, programs used, and vibration levels is shown in Figure 2.