1. Introduction
Due to the rapid aging of Korea, the demand for health care and medical expenditure are increasing [
1]. In order to promote the health of older adults, various goals have been established for the development and application of many programs [
2]. Health problems of the elderly can be prevented or delayed mainly through changes in health behavior and lifestyle, and chronic diseases of older adults are often approached in a preventive way to improve the quality of health-related quality of life (HRQoL) through management and maintenance rather than solely reliance on cures and treatments [
3,
4]. HRQoL can be defined as “how well a person functions in their life and his or her perceived wellbeing in physical, mental, and social domains of health” [
5]. Therefore, HRQoL is judged to have a different meaning from the quality of life or health.
Recently, much research has been conducted on enhancing physical function or preventing muscle loss [
6,
7]. The increase in body fat and sarcopenia in older adults is known to increase the risk of metabolic diseases and fractures, whereas physical activities can help reduce the risk of chronic diseases such as hypertension, diabetes, and stroke [
8,
9,
10,
11]. It is reported that physical activities reduce the risk of diseases and help prevent depression and fractures [
12]. In addition, activity improves physical strength and prevents physiological function decline, thereby increasing the independence of older adults, ultimately improving their quality of life [
11,
13,
14].
The World Health Organization (WHO) recommendation for the physical activity of the older adults aged 65 years and above is at least 150 min of moderate-intensity aerobic physical activity or 75 min or more of high-intensity aerobic physical activity or strength-enhancing physical activity per week [
15]. Also, for older adults with poor mobility, the WHO recommends 3 days or more per week of physical activity to enhance balance and prevent falls. However, the physical activity practice rate of the older adults in Korea is low, not even reaching 50% of the target [
16]. In addition, Koreans have exceeded the Organization for Economic Cooperation and Development (OECD) average life expectancy, and the life expectancy of Korean females is 85.4 years [
17]. Also, the prevalence of chronic diseases in older women is higher than males. When considering previous studies that show physical activities of older women differing greatly by region and economic conditions [
18], it is necessary to provide more active and diverse physical activity programs. However, multifarious domestic studies on the physical activities of older women are still insufficient. This study conducted a comprehensive investigation on the differences in health status, nutritional status, and life quality according to regular physical activities of older women. The results of this study will contribute as basic data for the development of social service programs.
4. Discussion
This study used Korean nationwide data to examine health indicators and analyze factors that affect the quality of life for older women over 60 according to their level of physical activity.
Aging causes a muscle-reducing condition called sarcopenia and can cause dysfunction in everyday lives [
30]. Therefore, regular exercise is recommended to increase daily physical activity [
31]. According to previous studies, regular exercise and intense exercise increase basal metabolism which has a positive effect on the prevention of muscular dystrophy [
32,
33]. Aerobic exercise causes significant changes in abdominal fat percentage, body fat percentage, and body fat mass [
34,
35]. In this study, the active group performing regular exercise had a slightly lower obesity rate than the inactive group. Moreover, the employment rate was higher, and the percentage of those with spouses was significantly higher for the active group. Regarding the subjective health condition evaluation, the active group had a higher response rate of being in good health, and the disease history/the current number of diseases was significantly lower than those of the inactive group. Prior studies have also shown that older people who are relatively healthier than others exercise more often than ordinary people, and participate in a wide range of leisure activities [
36,
37]. Of course, by contrast, one cannot ignore the fact that people with many illnesses inevitably fail to actively participate in any type of physical activity because of physical restrictions and limitations due to the presence and severity of a disease. According to Moon et al., higher income and education level led to a higher level of physical activity, but this study did not show a significant difference [
38].
Regarding lifestyle, the active group was less likely to receive stress and think of committing suicide compared to the inactive group. Moreover, the active group was more likely to have a regular eating habit than the inactive group. Kanamori et al. reported that even 10 min of exercise before sleep had a positive effect on blood vessels and reducing depression [
39]. In another study, implementing a 48-week exercise program on older adults over 65 with depression reduced the level of depression [
40]. As reported in many studies, physical activity can be a very effective intervention strategy for improving depression and stress conditions [
41,
42,
43]. Therefore, professionally developed body management methods that can strengthen the attitudes and motivations toward exercising with a goal to control emotions would be beneficial. As a result of the life quality indicators, the inactive group experienced significantly more problems in athletic mobility, usual activities, and pain or discomfort than the active group. According to Dauwan et al., degraded exercise ability or daily activities can cause diseases that lead to lower quality of life [
44]. As a lack of exercise can lead to illnesses, exercising regularly should be emphasized to improve the quality of life and maintain a healthy life.
The results of nutrient status and dietary quality analysis showed that despite no significant difference in the amount of energy and macronutrient, the active group had much greater consumption of vitamins and minerals compared to the inactive group. From the result, it can be deduced that a high level of obesity and skipping meal habits shown in the inactive group correlates with the result. There was also a previous study showing that older women had a higher skipping meals rate and insufficient intake of animal protein, calcium, and folic acid [
45]. Despite the majority of women preparing meals, the diversity of dietary intake was lower in women [
46]. Nutrients related to body functions are mainly energy, protein, calcium, vitamin D, and vitamin B groups. In particular, vitamin D receptors are an important key to preventing osteoporosis and sarcopenia in the elderly with muscle atrophy [
47]. Vitamin D supplementation improved quality of life and physical performance in the elderly [
48]. But this study does not have a comparison as there is not enough intervention research on exercise and consumption of older adults in Korea. Since this is a retrospective study, it is only compared to whether or not there is a difference in nutrient intake according to physical activity, but it cannot be interpreted as a causal relationship. However, considering the fact that people who regularly exercise tend to maintain healthy eating habits and consume sufficient nutrients, elderly people should also manage their dietary habits and overall eating amounts. In fact, considering a study that the participation rate and educational effect of regular and repetitive nutrition education is higher in women than in men [
49], it is necessary to improve nutritional status by applying customized education for elderly women.
Factors affecting the life quality of older women have been shown to be proportional to physical activities, the quality of diet, household income and education level. On the other hand, the life quality of older women is inversely proportional to their obesity, number of diseases, stress level, and the absence of spouses. The prevalence of hypertension, diabetes, and hypercholesterolemia in Korean older women were significantly higher than men after the age of 60, and the rate of undernutrition was reported to be higher than that of men [
50,
51]. The WHO has asserted that individuals are significantly affected by their own goals, expectations, standards, and interests in their culture or value system [
42]. However, it is difficult to improve the quality of life for elderly people because many other factors than those stated above should also be considered such as body condition, psychological condition, society, and economic condition. Moreover, in the comprehensive evaluation of physical activity/daily living ability, even though men typically were healthier than women, women were more likely to be exposed to depression. The average life expectancy is higher for women than for men, and women are more likely face the psychological burden of living alone, which leads to a lower quality of life. Thus, considering that many more factors can determine and reduce the life quality of women, it is pivotal to explore ways to improve the quality of life for older women.
This study has the advantage of utilizing a large number of data of older women by region. However, retrospective research may contain recall bias and there may be a limitation in explaining causal relationships. It cannot be ruled out that an individual’s non-activity does not depend on health conditions, and the two factors can confuse the causal nature of the phenomena that are explained in correlation.