{'fraction_non_alphanumeric': 0.030869761153672827, 'fraction_numerical': 0.01915277151870212, 'mean_word_length': 5.076396495071194, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 2, 'lorem ipsum': 0, 'www.': 1, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 2, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Chinese Compilation of Physical Activities in healthy adults aged 18–64: Categories and metabolic intensities

A Chinese Compilation of Physical Activities was compiled to estimate the energy costs of physical activities (PAs) using data on adults aged 18–64. Data were obtained from published articles and laboratory measurements. Databases, including PubMed, Embase, Scopus, Ebsco, Web of Science, Chinese National Knowledge Infrastructure, Wan Fang Data, National Science and Technology Report Service, Public Health Scientific Data were searched to collect data from inception to January 2022, on energy expenditure associated with PA in the healthy Chinese population. Two reviewers independently screened the literature and extracted, classified, and summarized data. Data were measured for 36 PAs using indirect calorimetry. Detailed descriptions of specific activities and metabolic equivalent values were provided by summarizing 241 physical activities in 13 categories. The first edition of the Chinese Compilation of PAs in Healthy Adults Aged 18–64(CCPA) was created. It provides valuable resources for people who regularly engage in physical exercise, researchers, educators, fitness professionals, and health or commercial sectors to quickly obtain various PA MET intensities. In the future, the energy expenditure of various PAs of different ages within the Chinese population can be measured based on the CCPA.


Introduction
In 2020, the World Health Organization (WHO) recommended that adults aged 18-64 engage in moderate-intensity aerobic physical activity (PA) to at least 150 min per week (min/wk) or 75 min/wk of vigorousintensity aerobic PA or optimal health benefits. Doubling the amount of moderate-and vigorous-intensity aerobic PA to 300 min/wk and 150 min/wk, respectively, confers additional health benefits. 1 Global reports have shown that 27.5% of adults did not meet the PA levels recommended for PA and health. 2 The lack of energy expenditure caused by physical inactivity is a leading cause of chronic diseases and obesity. 3 PA is defined as any bodily movement produced by skeletal muscles that require energy expenditure. 4,5 PA is a complex, comprehensive concept classified qualitatively based on function (occupation, sport, transportation, and housework) or quantitatively by intensity (sedentary, low, medium, and high). 6 In this study, the energy costs of PA in Chinese adults were evaluated directly or indirectly by measuring the energy expended in selected PAs or obtained by a search of the literature measuring the energy expenditure of PA in Chinese adults. In 1993, Ainsworth et al. published the first edition of the Compendium of Physical Activities (hereafter refer as Compendium). The Compendium is a comprehensive list of the energy costs of PA in healthy adults aged 16-65. 7 The Compendium lists the Metabolic Equivalent (MET) of PAs sorted by type and intensity as compiled from published literature or estimated when measured values are not found. The Compendium was updated in 2001 to form the second edition. 8 The latest version of the Compendium (3rd edition) was published in 2011, and a website was developed to provide a lookup for PA MET values and to download related resources. 9 The 2011 Compendium includes over 1 000 specific activities organized into 21 categories. Each specific activity has an associated MET value widely used by the general population, researchers, educators, fitness professionals, and the health or business sector. The Compendium is currently the most popular reference standard for PA research worldwide. However, the 2011 Compendium may not be entirely suitable as a reference standard for the PA energy expenditure of the Chinese population. The main reasons are as follows: 1) the Compendium is based on Western lifestyles, excluding traditional Chinese exercise such as Qigong and square dancing, 2) 260 (32%) specific activity MET values are estimated, and 3) some specific activity MET values may over-or underestimate PA in Chinese adults. 10 Researchers have investigated PA's energy expenditure in Chinese adults. However, a reference standard for the energy expenditure of PA in Chinese adults has not been systematically established. The 2021 PA Guidelines for Chinese 6 issued by the Bureau of Disease Control and Prevention in 2021 and the Energy Expenditure of Sports and Fitness published in 2013 by the General Administration of Sport of China comprehensively elucidated the MET values of various PAs. 11 However, most of the data were based on the 2011 Compendium. The Chinese Dietary Guidelines, updated by the Chinese Nutrition Society in 2016, also listed some typical moderate-and high-intensity PAs but did not specify the associated MET values. 12 In 2013, the China Institute of Sport Science (CISS) began a project to measure the energy expenditure of PAs in Chinese populations. In the first stage of the project, the CISS measured and published the MET values of 7 PAs in 1 000 urban and rural residents. 13 In the following stage of the project, the energy expenditure of more than 60 typical PAs was measured and uploaded to the National Population Health Data Center (https://www.ncmi.cn/). However, the current data were undisclosed and not available to the public for ten years from the upload date.
The purpose of this study was to establish the Chinese Compilation of Physical Activities (CCPA) to provide a standardized and comprehensive reference standard for PA energy expenditure in healthy Chinese adults. We compiled energy expenditure data on PA in healthy Chinese adults aged 18-64, uniformly coding its function, categories, and intensity. The CCPA aims to provide references for PA interventions, fitness programs, or exercise prescriptions to meet the needs of clinical and epidemiological research in Chinese populations.

Literature search
A literature search was conducted in PubMed, Embase, Scopus, Ebsco, Web of Science, Wan Fang Data, and Chinese National Knowledge Infrastructure (CNKI) Data from inception to January 2022. Different possible variations or combinations of the keywords used were: "metabolic cost," "calorimetry," "energy metabolism," "energy cost," and "oxygen cost." We also searched the Chinese National Science and Inclusion criteria for referenced articles include, 1) healthy Chinese adults aged 18-64, 2) data on PA energy expenditure was measured by indirect calorimetry (IC), and 3) literature for articles were published in English or Chinese. The studies that did not meet the inclusion criteria were excluded. The PRISMA diagram describes the selection process for studies (Fig. 1). The title, author, and year of the publication; characteristics of participants, including sex, age, weight, sample size, and energy expenditure; and experimental details such as measurement methods, activity duration, and specific activity description in the literature meeting the inclusion criteria were extracted. Two reviewers independently screened the literature, extracted, classified, and summarized data.

Measured PAs
To complement data from published articles, our laboratory measured the energy expenditure and calculated intensity categories for 36 of the 241 PAs in the CCPA (15%) frequently performed by Chinese adults. n ¼ 1 494 subjects residing near the testing site (age, 18-27 years) volunteered for the study. Subjects were asked to avoid alcohol, caffeine, and intense training for at least 24 h before all PA tests. Each PA test lasted 3-52 min in a laboratory (reading, walking, cleaning, folding clothes, video games, square dancing, resistance training, bicycling, recreation games, rope jumping, running) or a field setting (stair climbing and descending stairs, table tennis, tennis, badminton, Baduanjin, Tai Chi, Wuqinxi), depending on the PA type. We measured the energy expenditure with a portable indirect calorimetry system (Meta Max 3B, Cortex Biophysics Leipzig, Germany). 14 During laboratory experiments, the temperature was kept at 20 C-26 C, and the relative humidity was kept at 20%-40%. During the field tests, the average ambient temperature was 15 C-26 C. Every 10 s, the Meta Max 3B recorded oxygen consumption ( _ VO 2 ) and carbon dioxide output ( _ VO 2 ). The peak oxygen consumption or carbon dioxide production was defined as that which occurred with an RER greater or equal to 1.10 during any continuous 10 s period for all-out, maximal exertion. 15 METs were determined by dividing the measured peak _ VO 2 of PAs in ml/kg/min by a resting _ VO 2 of 3.5 ml/kg/min.

Coding scheme
The coding system for the CCPA consists of an eight-character alphanumeric Code, MET values, PA Categories, and Activity types (See Table 1 for the CCPA coding scheme).

Alphanumeric characters
An alphanumeric code (3 alphabetic and 5 numeric characters) was used to classify the PA category and activity types in the CCPA. The first three letters (CHN) are abbreviated for China. The letters are added to avoid confusion with the 5-digit code from the Compendium of PA. For the five numeric characters, the first two digits on the left represent the PA category, for example, "01" for "inactivity quiet/light" and "12" for "traditional Chinese exercise." The last three digits on the right represent activity types in a PA category. For example, "008" in the "inactivity quiet/ light" category (code 01) represents the PA activity "sitting, using a mobile (CHN01008)". In category 12, "traditional Chinese exercise," 010 represents the PA "Tai Chi, 24 forms of simplified, low posture (CHN12008)". Code sorting is based on the Chinese Pinyin and Non-Chinese strings in the general sorting rules for text items (GB/T 13418-1992).

CCPA
Chinese Compilation of Physical Activities PA Physical activity MET Metabolic equivalent CISS China institute of sport science CNKI Chinese national knowledge infrastructure

PA categories
Assignment of PAs to the proper activity categories was the initial step in coding the CCPA. The CCPA categories describe the purpose of a PA. The CCPA contains 13 categories related to lifestyle PAs (inactivity quiet/ light, walking, home activities, occupation, transportation) and physically active leisure-time PAs (bicycling, dancing, sports, running, conditioning and recreation, water activities, winter activities, and traditional Chinese exercise) ( Table 2).

PA types
PA types are the individual activities within each category. Units for the activity types are presented as a percent effort or subjective intensity, speed in kilometers per hour (km/h), steps per minute (steps/min), cycle ergometer revolutions per minute (rpm), and watts (W), race format (kayak strokes/min), or factions of the activity intensity. Identification of the speed or intensity of a PA assists users in assigning the appropriate code and MET values accurately. PAs without an indication of the speed or intensity are listed as "general."

MET values
METs are a simple, practical, easy-to-understand method for expressing PA energy expenditure. One MET is the ratio of the associated metabolic rate for a specific activity divided by a resting metabolic rate.   . MET values were obtained from published literature and unpublished data measured in studies on Chinese populations. The MET value of a specific activity includes one decimal place in the CCPA. If there were 2 or more activities of the same or similar type, the final MET value was determined by the average of the MET value for the multiple activities. For example, code CHN05003 is the average value of 6 measurements ( Table 3).

Calculation of kilocalorie energy expenditure
The energy expenditure values of specific activities have individual differences in the calculation related to body mass, age, and sex. The formula used for calculation is energy expenditure (kcal) ¼ MET value (kcal/kg/h) Â body mass (kg) Â activity duration (h). For example, a 55 kg person performing a 24-form simplified Tai Chi expends 10.5 ml/ kg/min (3 METs) twice a day for 30 min each time; the total daily energy expenditure of Tai Chi is calculated as follows: 3 METs Â 55 kg Â 0.5 h Â 2 times/day ¼ 165 kcal.

Results
The CCPA of Healthy Adults aged 18-64 includes an eightcharacter alphanumeric code that identifies 13 PA categories based on the purpose of PAs and 241 PA types and their associated MET values subsumed into a category. The number of PA types within a category differs depending on the availability of PAs measured. For example, category CHN05, "Conditioning exercise", includes 63 PA types, category CHN07, "running" includes 46 PA types, and category CHN12, "traditional Chinese exercise", includes 27 PA types. In comparison, category CHN03, "winter activities", and category CHN06, "transportation," include only three PA types each. The CCPA is presented in Table 4.

Discussion
The CCPA lists the energy expenditure of PAs in Chinese adults obtained from the published literature and measured in the laboratory. The CCPA contains an eight-character alphanumeric code that describes the assignment of 241 PA types with their associated MET values into 13 categories according to the purpose of the activity. The first three characters of the alphanumeric code indicate the origin of the CCPA (CHN, China), the first and second numeric digits indicate the PA category, and the last three numeric digits indicate the PA type within a category. The CCPA includes lifestyle (e.g., inactivity/quiet/light, transportation, occupation, and home activities) and conditioning activities (e.g., walking, bicycling, running, sports, general conditioning, and water sports) regularly performed by Chinese adults. The uniqueness of the CCPA is that it also includes a category for traditional Chinese exercise (category 12) that contains various forms of Tai Chi, dances, and martial arts.
The CCPA was developed to assign the energy cost of PAs in Chinese adults aged 18-64 years. The most prominent feature of the CCPA is that the MET values were obtained from energy expenditure measured in healthy Chinese adults. Of the 241 activity types in the CCPA, 205 (85%) were obtained from the published literature, and 36 (15%) were measured in our laboratory. Energy expenditure values range from 1. Researchers in China have gradually grown to value the application and popularity of the Compendium of PA. Since 1993, the Compendium has been the only resource to assign MET values for various activities. In 2020, the 2011 Compendium was translated and published in Chinese for use in Chinese populations. 16 The 2011 Compendium (Chinese-English version) can be downloaded from the Compendium website (https://sit es.google.com/site/compendiumofphysicalactivities/compendia).
For decades, Chinese scholars have been active in identifying PA energy expenditure, from the investigation and research on the energy expenditure of multiple occupations to the National Key Technology Support Program initiated in 2009. 13 They also have been active in basic data measurement tasks to measure PA energy expenditure for the National Key R&D Program (2018). 17 Such measures are included in the CCPA, coined as PAs with Chinese characteristics. For example, energy expenditure measurements of Tai Chi, Baduanjin, broadcast calisthenics, Wuqinxi, dragon dancing, and other uniquely Chinese PA increases the relevance of the CCPA for Chinese populations. The CCPA supplements the few PAs in the Compendium of PA that pertains to Chinese populations. The latest "Guidelines for PA for Chinese Adults (2021)" issued by the Chinese Ministry of Health's Bureau of Disease Control and Prevention cites MET values from the 2011 Compendium for use in their tasks. Due to differences in the PA types, methods, and populations used to measure PAs, MET values are not interchangeable between the Compendium and the CCPA. Hopefully, the CCPA will be considered a culturally relevant resource for national organizations. Therefore, the important historical significance of this study is that it establishes a CCPA suitable for the Chinese population based on the PA energy expenditure data of the Chinese population.
Like the Compendium of PA, 7-9 most data in the CCPA comes from published information. Data also are from the indirect calorimetry measurements from the 2018-2022 National Key R&D Program, including walking, running, cycling, 24 forms of simplified Tai Chi, Health Qigong Baduanjin, Health Qigong Wuqinxi, strength and conditioning, skipping rope, resistance training (e.g., squats), skipping rope, table tennis, badminton, tennis, Nintendo exergaming and other activities. 17 Currently, the CCPA targets the population aged 18-64 to correspond to the age group division from the PA Guidelines for the Chinese Population, 6 the WHO Guidelines on PA and Sedentary Behaviours, 1 and the U.S. PA Guidelines 2nd edition. 18 Due to the lack of PA energy expenditure data for Chinese preschool children, adolescents, and the elderly, it is difficult to present a CCPA for these groups at this time. For related research, the PA compilation of preschool children by Brandes 19 and Puyau 20 et al. and the Youth Compendium of Physical Activities 21 are excellent references for children and adolescents.

Limitations and future plans
The most valuable role of CCPA is that it provides a classification system for PAs with associated MET values specific to Chinese adults. However, neither the Chinese version nor the Compendium of PA can fully assess the actual energy expenditure of PAs 9 as the accuracy of CCPA can be affected by several factors. First, inconsistencies in the way data are collected between studies may increase variability in MET values for activity types, especially when MET values are averaged across studies for similar modes of PA. Second, descriptions of some PAs do not contain all the details about PAs needed to identify the context of an activity. For example, the CCPA entry, "CHN09016, 7.4 METs, sports, badminton general," is so brief that it is impossible to identify whether the alphanumeric code represents singles or mixed doubles, competitive or recreational games. Third, individual differences exist in performing the same PA by weight, age, sex, activity efficiency, suitability for particular circumstances, and reported PA patterns. Forth, the CCPA is not suitable for people with mobility impairments and those in wheelchairs. For related research, readers are referred to Conger et al.'s list of MET values for the population using manual wheelchairs. 22 When using the CCPA MET values used to calculate the total energy expenditure of individuals, the resultant kilocalorie values represent only an estimate of the energy expenditure of a PA. Further, the excess postexercise oxygen consumption in high-intensity sporting activities is often ignored when measuring the oxygen consumption of PAs. This omission can lead to an underestimation of the total energy expenditure, 23 especially for short-term exercise.
Plans for the CCPA are to continue collecting and updating values for the energy expenditure of PAs in Chinese persons in all age groups. Our focus will include collecting data for traditional Chinese sports (such as dragon boat, dragon and lion dance, shuttlecock, croquet, martial arts, sports dance, and kite sports), with all PA data derived from actual measured energy expenditure data. We also aim to establish a proprietary Mandarin language website to promote, disseminate, and popularize the CCPA and encourage research institutions and scholars to submit research reports to the website. Furthermore, we will seek more journal and data platform collaborations to attract unpublished relevant studies regarding the PA energy expenditure in Chinese populations. This plan is modeled after the 2015 Working Group on the Youth Compendium of Physical Activities that collected 17 manuscripts, including data for children and teenagers aged 3-18, and published the information in a special supplement to the Journal of Physical Activity and Health. 24 Lastly, if there are many data sources, we will evaluate MET values for the same PAs using evidence-based and meta-analysis to increase the CCPA accuracy further.

Conclusions
The CCPA uses an eight-character alphanumeric code to organize 241 PAs and their associated MET values in 13 categories for use in healthy Chinese adults aged 18-64. MET values were obtained by reviewing the Chinese literature and from PA energy expenditure measurements. The CCPA provides a valuable resource for Chinese people who regularly engage in PA, researchers, educators, fitness professionals, and health or business sectors to quickly obtain MET values for various levels of PA. The CCPA also is helpful for those developing PA or dietary guidelines for residents, PA interventions, fitness programs, and exercise prescriptions.

Submission statement
This manuscript has not been published or presented elsewhere in part or entirety. Its publication is approved by all authors and tacitly or explicitly by the responsible authorities where the work was carried out, and, if accepted, it will not be published elsewhere without the written consent of the copyright holder, including electronically in the same form. An Chinese version of CCPA was published in the fifth issue of Chinese Journal of Sports Medicine. The study design was approved by the appropriate ethics review board. We have read and understood your journal's policies, and we believe that neither the manuscript nor the study violates any of these.

Ethical approval statement
Each subject was required to fill out an informed consent form to understand the details and specific requirements of the test. The study measuring the oxygen consumption of selected PAs was approved by the Institutional Review Board of Beijing Sport University (No. 2019099H).

Data availability statement
The datasets generated and/or analyzed as part of the current study are not publicly available due to confidentiality agreements with funders. However, they can be made available solely for review and not for publication from the corresponding author upon reasonable request.