THE RELATIONSHIP BETWEEN PHYSICAL ACTIVITIES AND COGNITIVE FUNCTION IN THE ELDERLY

The elderly will experience an aging process that is characterized by physical changes, intellectual changes, and a decrease in various body functions. Deterioration of intellectual function including cognitive function is one of the functions that will decrease in the elderly. Physical activity is a factor that can inhibit cognitive decrease in the elderly. One of the preventive actions that can be done by the elderly in slowing down the decrease of cognitive function is to increase physical activity. Physical activity is thought to stimulate nerve growth which might inhibit cognitive decrease in the elderly. When doing physical activity, the brain will be stimulated by talamus so that it will increase the Brain Derived Neurotropic Factor which plays a role in keeping nerve cells fit and healthy. The purpose of this study was to identify the relationship between physical activity and cognitive function in the elderly. This study was a quantitative study with a categorical correlative analytic method. The study used cross sectional study design. The chi-square test and ordinal logistic regression test were used for data analysis. The results of this study stated that the overall physical activities which were exercise, mild activity, heavy activity, use of stairs and participate in social activities showed a significant relationship to cognitive function. Participating in social activities and mild activity were the most significant physical activities that showed relationship to cognitive function, with p-value = 0.001 < 0.05. In conclusion, the findings highlight that the choice of appropriate physical activity can help to maintain cognitive function in the elderly.

composition of the largest elderly population in the world after China, India and USA. Based on the population projection data, it is predicted that the number of elderly people will be increasing to 27.08 million in 2020, 33.69 million in 2025, 40.95 million in 2030 and 48.19 million in 2035. The large number of elderly population makes Indonesia at the stage of "Aged Society". It means that the proportion of population at the age of 60 and over is more than 10% of the total population (Pusdatin, 2017). The data of the elderly characteristics in Kasin sub district, the working area of Bareng Primary Health Care, showed that 78.2% of the elderly are still able to do doing daily activities, 82.4% are still able to do mild activities, 69.7% never do any house repairs, 62.7% are able to manage their finance, and 61.3% of them are still able to complete outdoor activities.
Many factors that contribute to the decreasing cognitive function in the elderly include individual factors, disease, and the environment. Age, genetic, and educational level are the individual factors that can contribute to the decreasing cognitive function in the elderly. While, hypertension, diabetes mellitus, and high cholesterol are the factors that increase the chances of cognitive decrease. Environmental factors that increase one's chances of experiencing cognitive decrease include social engagement and activity (Wreksoatmodjo, 2014). Poor cognitive function can be used as a marker of general health status in the elderly and as a predictor of death. Decreasing cognitive function is the biggest cause of inability to carry out daily activities in the elderly and the most common cause of dependence on others in self-care (Reusser, Willekens, & Bonneux, 2011).
Physical activity is a factor that can inhibit cognitive decrease in the elderly. Physical activity is thought to stimulate nerve growth that might inhibit cognitive decrease in the elderly (Sauliyusta & Rekawati, 2016). When doing physical activity, the brain will be stimulated by talamus so that it will increase the Brain Derived Neurotropic Factor that plays a role in keeping nerve cells fit and healthy (Sanchez & Gough, 2013). Previous studies indicate that there is a tendency for the elderly to limit their activities due to a decreasing health.

METHODS
The type of study was a quantitative study with a categorical correlative analytic method. The study used cross sectional study design. The study was conducted in January 2020 in sub-district of Kasin, the working area of the Bareng Primary Health Center in Malang. The study population was all the elderly who came to the Integrated Healthcare Center in Kasin, the working area of the Bareng Primary Health Center in Malang. The elderly who became the respondents were those who aged 60 and over, domiciled at least 1 year in their place, and were willing to become respondents. Respondents were obtained using random sampling technique. The total respondents were 51 people. The Ambbreviated Mental Test (AMT), the physical activity questionnaire, and the demographic data questionnaire were used to get study data. The data used in this study was primary data obtained directly from the elderly during the Integrated Healthcare Center visitation. Based on the study design that was used, the study examined all the variables at the same time. Each respondent would be examined for cognitive functions and daily physi-cal activities. Data analysis was performed the chisquare test and ordinal logistic regression test.

Characteristics of Elderly Cognitive Function
Based on table 3, it was obtained that 39 elderly people (76.5%) had normal cognitive function. Table 4 showed that the exercise variable was 0.290 with p-value 0.003 (< 0.05), the mild activity variable was 0.327 with p-value 0.001 (< 0.05), the heavy activity variable was 0.490 with p-value 0.002 (< 0.05), the usage stairs variabel was 3.285 with p-value 0.003 (< 0.05), and the participation in social activities was 0,000 with p-value 0.001 (<0.05). This results mean that the overall physical activities which were exercise, mild activity, heavy activity, use of stairs and participate in social activities significantly influence cognitive function as measured by the Ambbreviated Mental Test (AMT) instrument.

Relationship between Exercise and Cognitive Function
Significance value showed the result of 0.003 (p <0.05), which showed that there was a significant relationship between exercise and cognitive function. Physical activity is understood as any body move-ment that requires expenditure of energy such as cycling and doing gymnastics (Polan, Asrifuddin, & Kalesaran, 2018). In the elderly, increasing age has an impact on daily physical activity. The choice of exercise should be adjusted to the physical ability of elderly to maintain the intensity and duration of the exercise. In the elderly, a decrease in the intensity and duration of exercise can accelerate to cognitive decrease. The results of this study are supported by previous study which says that the frequency of exercise with a minimum of three times a week for the elderly can improve overall body fitness (Muzamil et al., 2014). The elderly who exercise have cognitive abilities 2.47 times better than the other elderly who do not exercise. Other studies by Dayamaes (2013), found that there was a relationship between exercise and cognitive function in 55-91 years old men and women. Individuals of this age who are diligent in exercising have better reasoning, memory, and reaction time abilities than individuals who lack or never exercise.

Relationship between Mild and Heavy Activity and Cognitive Function
Significance value showed the number 0.001 (p < 0.05) which indicated that there was a significant relationship between doing mild activity and cognitive function. For the heavy activity, the significance value shown was 0.002 (p < 0.05) which stated if there was a significant relationship between doing heavy activity and cognitive function. The results of this study are supported by previous study which shows if there is a correlation between physical activity and cognitive function in the elderly. The higher the physical activity, both heavy and mild activity, the higher the cognitive function score (Izzah, 2014). In household activities, heavy physical activities can be interpreted as washing clothes, mopping, lifting weights, and repairing house. These activities result in calorie expenditure of 7.5 to 12 kcal per minute (Leitzmann et al., 2015).Meanwhile, mild activity category at home are such as cleaning the room, shopping, and sweeping the house. Mild and heavy activities are forms of physical activities that can facilitate the process of neurotransmitter metabolism. The basic ingredients of neurotransmitters are amino acids which are one of the nutrients for the brain and have an important function in alertness increase, errors reduction, and thinking stimulation. The process of neurotransmitters will stimulate the process of neurogenesis and maintain brain plasticity which is the brain's ability to make new interconnections of nerves. This process plays an important role in inhibiting brain tissue hypertrophy which can cause  neural degeneration which has an impact on cognitive functions (Muzamil et al., 2014).

Relationship between Using Stair and Cognitive Functions
The significance value indicated the result of 0.003 (p < 0.05) which stated that there was a significant relationship between the use of stairs and cognitive function. There are 3 types of physical activity to maintain physical health, which are endurance, flexibility, and strength. Endurance is defined as activities such as walking, jogging, swimming, gymnastics, tennis, and gardening. Flexibility are activities such as tai chi gymnastics, yoga, washing clothes, and mopping the floor. Meanwhile, strength is a variety of activities such as push-ups, using stairs, lifting weights, and carrying groceries. One of the assumptions between physical activity and cognitive abilities is that using stairs, as one of the physical activities, is able to improve cognitive function through increasing cardiovascular function. The increase of cardiovascular function can increase the speed of brain processing, memory, mental flexibility and cognitive function (Nisa, 2015).
The use of stairs in the elderly is classified as moderate physical activity with calorie expenditure of 5 to 7 kcal per minute (WHO, 2010). Cognitive function in the elderly with active use of stairs is significantly better than the elderly who do not actively do it. The use of stairs can improve cognitive performance through increasing levels of neurotrophin, increasing body fitness, reducing depression, maintaining blood flow to the brain and increasing brain nutrition. The risk of neurodegenerative disorders such as Alzheimer's and dementia can also be reduced through physical activity.

Relationship between Participating Social Activities and Cognitive Functions
The significance value shown was 0,000 (p < 0.05) which stated that there was a significant relationship between participating in social activities and cognitive function. The elderly who participate in social activities fulfill their social engagement functions. The elderly who participate in social activities have the opportunity to interact with their environment (Wreksoatmodjo, 2014). Participating in social activities and interactions with other people in elderly can help to stimulate cognitive function and slowing senility (Yuliati, Baroya, & Ririanty, 2014). Social participation can influence neural synaptogenesis, so that it can stimulate nerve branching in the hippocampus which can reduce cognitive impairment.

CONCLUSION
Social activities and mild activity are physical activities that show the most significant relationship to cognitive function. Increasing age can reduce a person's ability to do physical activity. The choice of appropriate physical activity can help to maintain cognitive function in the elderly.