1. Introduction
Regular physical activity and exercise are essential for maintaining good health and improving overall well-being [
1]. Physical activities can contribute to cardiovascular health, muscular strength and endurance, weight management, and mental health. However, the COVID-19 pandemic has severely affected human health and lifestyles worldwide in the past few years. The literature shows adverse impacts on health among various populations, including adolescents and young adults, leading to decreased physical activity, increased sedentary behavior, and body image problems [
2,
3,
4,
5].
A systematic review of 66 studies comprising 86,981 participants, including different populations, reported decreased physical activity and increased sedentary behavior during community lockdowns in various countries [
6]. Another systematic review of university students’ perception of body image and physical activity found that they had reduced physical activity time and intensity but increased sedentary activity time during the pandemic [
3]. Furthermore, females were more physically active than males. Similarly, a Chilean study of 469 university students found that sedentary lifestyles and a lack of physical activity negatively affected students’ subjective well-being and general mental health during the pandemic [
4]. Despite the pandemic, the World Health Organization emphasized the importance of maintaining sufficient physical activity levels and decreasing sedentary behavior to sustain good health [
7].
A healthy body image involves accepting and respecting one’s body, regardless of size or shape, and recognizing the importance of overall well-being beyond physical appearance. Body image has become a global health concern and affects different populations, especially adolescents and young adults [
8]. A previous European study investigated 328 normal-weight French male university students who said they were concerned about their body image. The majority (85%) were unsatisfied with their muscularity, which may cause higher risks of depression and eating disorders [
9]. An evaluation study of Greek fitness center members showed significant differences in body image among those with different BMI self-classifications (normal, overweight, and obese) [
10].
In Asia, the perception of being overweight is more prevalent in South Korea than in Taiwan [
11]. Women are more susceptible to societal pressures to maintain a thin body and the ideal body image perception than men [
11,
12]. Similarly, a Taiwanese study of 2095 adult males’ and females’ perceptions of body shape found that age and gender influenced the respondents’ views on body size [
13]. Females were more likely to misperceive themselves as overweight than males. Additionally, males were more likely to misperceive themselves as underweight than females. A local study examined 358 Hong Kong Chinese senior secondary school girls’ body image and eating attitudes, finding that they desired slimness even though only a minority (4.8%) were overweight [
14]. Interventions are recommended to improve distorted body image perception [
11].
However, the relationships between body image, the significance of physical activity and sedentary behavior, and the concept of health and illness are complex and interconnected, especially under the implementation of city lockdowns and social distancing measures during the pandemic [
2,
3,
6,
15,
16,
17,
18]. Goh et al. (2023) systematically reviewed 16 quantitative and 12 qualitative studies from various countries [
16]. They reported a comparatively constant association between individuals who expressed higher or lower satisfaction with their bodies and physical appearance. Individuals more satisfied with their body parts were inclined to participate in health checks or screening behaviors. In contrast, those dissatisfied with their body image were less likely to engage in health-related activities [
16]. An Iranian study of 535 female high school students conducted in 2020 found significant positive correlations between physical activity levels and body image [
2]. A Kosovo study investigated the impact of lockdown measures on the population before and during the pandemic. It reported significantly reduced physical activity in youth (≤25 years), young adults (25 < years ≤ 35), males, overweight individuals (BMI > 25), respondents who resided in urban areas, and young people who were increasingly sedentary during home confinement [
17]. Additionally, Runacres et al. (2021) reviewed and analyzed 40 studies concerning the pandemic’s impact on sedentary time and behaviors. They found that children and adults were more undesirably influenced than older adults [
18].
The WHO also highlighted the importance of maintaining physical activity and reducing sedentary behavior at home during the pandemic to decrease the risk of severe COVID-19 outcomes [
7]. Many public health policies and strategies were implemented worldwide, including lockdowns and restricting access to public areas for physical activity. Likewise, the Hong Kong government also enacted stringent social distancing measures to minimize cross-infection to prevent morbidity and mortality. Hong Kong is a small (1114.57 km
2) urban city densely populated with about 7.54 million citizens [
19]. The average living space per person is also small, at ~13.6 m
2 [
20]. Like other metropolitan cities with efficient transportation and sedentary lifestyles, physical inactivity in Hong Kong is not uncommon [
21]. The pandemic further exacerbated the problem due to the closure of public/private recreation areas and premises for sports/physical facilities. The local citizens’ opportunities to access safe indoor/outdoor spaces for physical activity were significantly reduced, particularly for those unable to engage in physical activity at home, adversely affecting the general public’s physical health. Indeed, insufficient physical activity can increase the risk of developing diabetes mellitus, obesity, hypertension, heart disease, cerebrovascular disease, and various forms of cancer [
22].
Local studies found that Hong Kong citizens extensively reduced their walking frequencies and sports activities but increased home-cooked meals during the pandemic [
15]. Additionally, secondary school students’ physical activity (moderate to vigorous exercise) significantly decreased [
23], and local primary school children’s physical fitness and body mass index (BMI) were negatively impacted [
24]. However, the impact of public health policies and social distancing measures on local young adults’ body image, physical activity, and sedentary lifestyle remains unclear. A comprehensive understanding of the impacts on young adults’ physical activity and related behaviors is essential; it could assist in establishing appropriate public health strategies and programs to promote regular physical activity habits and minimize sedentary behaviors in the future or in similar lockdown situations. Thus, this study aimed to investigate young adults’ physical activity, related behaviors, and perceptions of body image during the COVID-19 pandemic in Hong Kong.
4. Discussion
During the COVID-19 pandemic, people’s health and lifestyle were inevitably affected worldwide. Due to the prolonged pandemic, the Hong Kong government extended social distancing measures for months to prevent cross-infection. These measures included universal mask-wearing, the prohibition of group gatherings, school closures, indoor and outdoor sports premises closures, restrictions on catering businesses’ opening hours, stay-at-home advice, etc. [
34]. Hospital and institutional confinement of infected and close-contact cases was implemented [
31]. Additionally, the Hong Kong government and some companies implemented work-from-home (WFH) strategies from time to time. These measures also affected Hong Kong residents’ health and daily lifestyles, consistent with other local studies involving various age groups and populations [
15,
23,
24,
35,
36,
37].
The World Health Organization (WHO) recommends that adults aged 18–64 perform at least 300 or 150 min of moderate- or vigorous-intensity aerobic physical activity per week, respectively, to achieve health benefits [
7]. Regular physical activity reduces the risk of chronic diseases and enhances cardiopulmonary function [
22]. Based on the WHO statistics [
38], 80% of adolescents and 31% of adults worldwide could not accomplish the recommended level of physical activity during the pandemic [
38]. In Hong Kong, the Health Behavior Survey of 5903 Hong Kong citizens aged 15 or above reported that 16.8% of respondents (15.2% of males and 18.3% of females) had insufficient physical activity before the pandemic [
39]. Unsurprisingly, a noticeable increase of 24.8% of citizen respondents (including 22.8% of males and 26.5% of females) had inadequate physical activity during the pandemic [
22]. As inactive individuals face a 20 to 30% higher mortality risk than those who are fully active [
38], strategies are required to encourage citizens to increase physical activity and exercise daily.
By comparing the WHO’s recommendations with our study data collected in 2021, it was found that most young adult respondents (77.2%,
n = 315) did not engage in regular physical activity (40.9%,
n = 167) or did so for <2.5 h per week (36.3%,
n = 148), and only 22.3% (
n = 91) joined any fitness club/class. The decrease in physical activity may be attributed to the closure of public and private recreation centers and fitness clubs due to social distancing measures, as noted in other studies [
3,
6,
15]. Indeed, the opportunities for local citizens to access safe indoor/outdoor premises for physical activity were significantly reduced in such a densely populated, small urban city with limited living space, adversely affecting the intention to engage in physical activity. Local citizens considerably reduced their moderate- and high-intensity physical activities and walking exercises [
15]. Similarly, another local study conducted in 2020, which involved 631 young adults aged 18–35, reported that only 30% achieved the WHO physical activity guidelines, 57.8% did not engage in vigorous physical activity, and 70% had reduced physical activity [
31].
Furthermore, the Health Behaviour Survey of Hong Kong citizens found that 38.9% engaged in ≥8 h of sedentary behavior, such as sitting or reclining at work, at home, or with friends [
40]. Our study found that a higher rate (45.1%) of young adults engaged in 8–12 h or >12 h of sedentary behavior during the pandemic. The results are consistent with those of research showing that university students [
3] and local young adults [
35] increased their sedentary behavior. The lockdown had a more severe impact on children (<18 years) than on young and older adults, leading to an increased sedentary time [
18]. This increase in sedentary time negatively affected mental well-being, psychological states, and quality of life. Therefore, there is a need for global and local efforts to establish strategies and promote a reduction in sedentary time.
The Hong Kong Population Health Survey (PHS) conducted from 2020 to 2022 revealed that 54.6% of the general population aged 15–84 were either overweight (22.0%) or obese (32.6%), with women aged 65–84 (57.0%) and men aged 45–54 (74.6%) being more susceptible to obesity and overweight [
41]. Among our 408 young adult respondents (aged 18–29), the BMI results showed that 52.5% had a normal weight, 18.6% were underweight, 12.0% were overweight, and 16.9% were obese (based on self-reported weight and height), which was better than the general public.
In our study, we found significant positive correlations among different factor subscales. Compared with the norms of the United States national survey of males and females for the MBSRQ subscales [
29,
42,
43], our study results showed lower mean scores on all the seven factor subscales, except for female illness orientation (3.24 vs. 3.21). This suggests that local young adults may be less satisfied with their body image, physical attractiveness, fitness, and health than individuals in the United States. However, local young female respondents showed a higher alertness to physical illness.
Furthermore, BMI, regular physical activity, and joining any fitness club or class were found to be significantly associated with different factors or additional subscales of the body image construct. Body image refers to how individuals perceive and evaluate their body’s appearance. This perception can influence their thoughts, feelings, and behaviors related to physical activity and fitness [
8]. Previous studies found that exercise was associated with a positive body image [
44], and individuals who exercised had a more positive body image than those who did not [
44]. Additionally, we found that the respondents who engaged in regular physical activity and joined fitness clubs or classes valued fitness and health and were actively involved in activities that enhanced or maintained their fitness and health, while those who had an underweight BMI were not active.
Females are usually more concerned about their weight or body size than males [
13] and demonstrate more dissatisfaction regarding their body image [
45]. Consistent with previous studies of gender differences in body weight or size [
13,
46], the young female respondents were more likely to perceive themselves as overweight (35.1%) than males (32.3%), and the male respondents were more likely to perceive themselves as underweight (18.6%) than females (13.4%). Individuals with a self-stigma of being overweight have greater behavioral intention to participate in physical activities in order to control their weight [
47]. Additionally, our female respondents focused more on their appearance and were more concerned about body fat, weight vigilance, dieting, and eating habits than males. The results align with those of a study of Korean and Taiwanese individuals conducted by Noh et al. (2018), which observed that females experience more significant societal pressure to be thin than males, impacting body image. Indeed, most women prefer to be slimmer and are likely to overestimate their body weight or size regardless of their actual size [
11,
12]. In contrast, our male respondents were more confident in their physical fitness, valued their body fitness, and were more concerned about physical activities. Males prefer exercising instead of dieting to alter their body shape, e.g., increasing muscle tone and muscle mass through physical activity [
12].
After understanding the impacts on young adults’ physical activity and related behaviors through this study, the results could inform and assist in establishing appropriate public health strategies and programs to promote regular physical activity habits and minimize sedentary behavior in the future or similar emerging infectious diseases with social distancing and institutional or home confinement. For instance, collaboration among stakeholders, such as non-profit organizations, schools, and community centers, could be promoted to establish more recreational activities and behavioral change projects for various populations to integrate physical activity into their daily lives, e.g., regular sports training courses and Physical Activity Week for students, as well as Physical Activity/Sports for ALL campaigns for citizens. Online resources, such as physical activity videos or virtual sports exercises using digital technology to encourage home fitness in future pandemics requiring isolation or social distancing measures, could also be considered.
The study data were gathered using purposive and snowball sampling through online questionnaires filled out by young adults. The sampling methods did not adequately warrant representatives or subject randomization and may raise concerns about bias or generalizability limitations. A future study could consider an appropriate randomized sampling method to minimize potential sampling bias. Although online surveys have several advantages, such as saving time and money when social distancing measures are implemented, the ambiguity of data validity and self-assessment reliability are disadvantages [
48]. Although the respondents were encouraged to contact the researchers if questions arose, online self-report questionnaires may lead to reporting bias or a misunderstanding of the questionnaire items. For instance, the BMI was calculated using self-reported data (weight and height) instead of actual measurements.