Twenty-one elderly women residing in a community of Beijing participated in the study. The participants were 60 to 72 years of age (mean age 65.95 ± 3.85 years), healthy, had normal vision or vision that was corrected to normal, and had mental state test scores ≥24 points. The Capital University of Physical Education and Sports (CUPES) Ethics Committee (approval No. CUPES-2018-06-15-01) approved the study and all participants signed informed consent forms.
Yale physical activity scale
The YPAS is one of the scales that are commonly used to measure time spent in physical activity, energy consumption and related activity index . It assesses the participant’s level of physical activity, recreational activities and domestic activities. The recall period is designated as a specific week in the month prior to the study. The target population includes healthy elderly people aged 60 and over.
The questionnaire consists of two parts. The first part lists 27 activities that are divided into three categories: household activities (including yard activities and care activities), exercise activities and entertainment activities. The respondents were asked to record the time (hours) spent on each activity in a week according to whether they performed the activity during an average week in the previous month. The total time is calculated by adding the time spent in all listed activities. Energy consumption (kcal/week) is calculated by multiplying the time spent in each activity by the corresponding intensity code.
The second part consists of nine questions designed to assess the participant’s level of participation in various types of physical activity, expressed as an index. The index of the five types of activities is calculated by multiplying the duration of each of the following activities by the specified weighting factor: (a) high-intensity activities; (b) leisure walking; (c) movement; (d) standing; (e) sitting. These indices are added to determine the sum index of the YPAS.
The time required to complete the YPAS is approximately 20 minutes. The questions that comprise the first part of the questionnaire are short and do not refer to difficult or controversial terms. The second part of the questionnaire includes questions about high-intensity physical activities and leisure walking; these need to be properly explained to the participants and the participants need to be given a clear definition of each activity.
Omegawave body function test system
The body function test system (Omegawave diagnostic system) can collect the nerve fatigue index and energy metabolism index of participants under laboratory conditions. The greatest advantage of this system is that it is easy to use and can be monitored in real time. The participants were tested in a supine position in a quiet environment. The test is divided into a “routine test” and a “complete test”. The routine test requires approximately 5 minutes to obtain an evaluation of the participant’s cardiac function and energy metabolism system. The complete test, which requires approximately 15 minutes, performs a functional evaluation of the participant’s central nervous system, cardiopulmonary, and liver transformation functions and his or her hormonal system.
The Omegawave diagnostic system is a new system that is designed to evaluate the state of physical function; it can measure VO2max and other indicators in elderly individuals. Research shows that the Omegawave diagnostic system has a high correlation with the results of traditional laboratory tests of function . Traditional laboratory testing requires the elderly to do their best, and an Omegawave diagnostic system may be more suitable than other systems for testing the elderly.
The Omegawave diagnostic system was used in an environment in which the air humidity was 33% and the room temperature was 22 ± 1 °C. The test environment was quiet, and the lighting was appropriate. The participants did not consume any alcohol or drugs within the 24-hour period prior to the test. Before the test, the tester wetted the heart rate belt and assisted the participants in wearing the belt accurately. After putting on the heart rate belt, the participants were required to lie down for 1 min. The surface skin where the electrode sheet was to be applied was wiped with an alcohol-soaked cotton ball. The electrodes were applied to the thenar of the participant’s dominant hand and to the center of his forehead. After the instrument showed that the connection was successful, the machine was clicked to start the test. During the test, the participant was required to close his eyes, remain quiet, and refrain from moving or talking. The collection time was 4 minutes.
Relevant research shows that there is a significant correlation between aerobic capacity measured using the Omegawave diagnostic system and aerobic capacity measured using traditional test methods and that using the Omegawave system to test aerobic capacity is effective. The traditional aerobic capacity test requires participants to work as much as possible. The working characteristics of the Omegawave diagnostic system are more suitable for monitoring the aerobic capacity of the elderly.
To ensure cultural equivalence between the simplified Chinese version of the YPAS and its original English version, a standardized translation procedure is used in this study, including six stages (initial translation, synthesis of the translations, back translation, test of the prefinal version and appraisal of the adaptation process) . In the translation of the scale, it is assumed that the physical activity structure used in the YPAS is generally culturally suitable for individuals residing in communities in mainland China. In addition, the scale should be adapted to make it useful in cross-cultural research and comparison. Two scholars in the field of sports science analyzed the theoretical background of the questionnaire and considered the differences in culture and language in mainland China. The physical activity structure used in the YPAS is culturally suitable for communities in mainland China. Two independent bilingual scholars translated the questionnaire into Chinese and compared and retranslated the simplified Chinese version with respect to the original YPAS. Because courtyard activities are less often participated in by elderly groups in mainland China and gardening activities are more often participated in, “lawn cutting” and “cleaning trails” in the section on courtyard activities are replaced in the simplified Chinese version by “pruning bonsai” and “carrying flower pots”. In addition, because table tennis is very popular among the elderly in mainland China, “squash” is replaced by “table tennis” in the section on entertainment activities.
Each participant participated in the test twice. During the test, the basic information on the participant was first collected, and the test procedure was described to the participant in detail. The participants were familiar with the questionnaire and completed the scale to reflect their own actual situations. The participants had unlimited time to answer the questions on the YPAS. The entire filling process of completing the scale was guided by a trained master. After completing the scale, each participant wore the Omegawave diagnostic system and was tested by an experienced tester; the participant’s maximum oxygen consumption (VO2max) and energy metabolism system adaptation index (EMSAI) were recorded. One week later, the participant returned to the same place, completed the YPAS again, and participated in a second Omegawave test. The reliability of the YPAS was evaluated based on the consistency of the two measurements, and its validity was verified based on the relevant indicators of the Omegawave diagnostic system.
The reliability of the YPAS was tested using a one-week interval retest procedure. SPSS (version 23.0; IBM Corp., Armonk, NY, United States) was used to process and analyze the data. The results were analyzed by descriptive statistics, intraclass correlation coefficient (ICC) and Pearson correlation analysis. The significance level was set at p < 0.05.
The simultaneous validity was evaluated by comparing the results of the YPAS with those of the Omegawave diagnostic system. SPSS (version 23.0; IBM Corp.) was used to analyze the descriptive statistics and Pearson correlation of the data, and the significance level was set as p < 0.05.