PHYSICAL EXERCISE AS A PHYSIOLOGICAL MODULATOR OF IMPROVING CARDIOVASCULAR HEALTH IN OBESE WOMEN

The study purpose was to analyze the effective form of physical exercise in improving cardiovascular health in obese individuals. Materials and methods. Twenty-four (24) obese adolescents, aged 20–24 years, who met the criteria were selected as participants. The participants were divided into 3 groups, namely the control, the strength training


Introduction
Obesity is a very complex health problem (Chen et al., 2021), and is an independent factor, increasing the risk of heart disease, type 2 diabetes mellitus, and other diseases (Jamka et al., 2021). It was found that an increase in obesity was directly proportional to an increase in heart disease (Amaral, 2014), and in overweight individuals have twice the probability of developing heart disease, in obese individuals the probability rate can reach 10 times that of individuals with normal weight (Pinckard et al., 2019). However, in modern society heart disease is still considered the most common health condition (Machado et al., 2021), with its main contribution to high blood pressure (Schroeder et al., 2019), which has the highest prevalence rate (Shim & Kim, 2017). Data shows that high blood pressure reaches 29% and is predicted to continue to increase, as well as being the main risk of death (Schroeder et al., 2019). It is estimated that 25% of deaths each year are due to heart disease (Jamka et al., 2021), and the prevalence rate increases to 31% deaths every year (Brandão et al., 2022). Therefore, heart disease can be a major risk factor for increased mortality and morbidity (Pinckard et al., 2019).
Obesity is a significant contributor to an increase in heart disease, especially high blood pressure (Tayagi et al., 2020), myocardial infarction, (Almutawa et al., 2020) and coronary artery disease, (Machado et al., 2021), is also a major risk factor for death (Schroeder et al., 2019). Pharmacological approach (Zimmer et al., 2019) and an eating behavior change approach using diet in combination with medication (Shim & Kim, 2017). It has been used to treat heart disease and cardiovascular health. However, other experts stated that the approach with drugs (pharmacology) in the long term is still considered less than ideal (Almutawa et al., 2020). Meanwhile, other experts stated that the approach with physical exercise was more appropriate and physiological to improve heart health in the long term (Ramos et al., 2019) and physical exercise is also considered an effective codulation not only for heart health, but also for improving cardiac performance (Durrani & Fatima, 2015). Physical exercise, is a modulation associated with the level of energy expenditure, decreased fat mass and increased skeletal muscle mass as well as heart muscle (Saeidi et al., 2022;Rejeki et al., 2021).
Physical exercise is very beneficial, not only for heart health but also for general health, which is believed to be an effective non-drug method of lowering and replacing drug doses (Shim & Kim, 2017), thereby so as to reduce and prevent non-communicable diseases including improving heart health (Thirupathi et al., 2021). Previous research has shown that regular physical exercise increases high-density lipoprotein (HDL), controls insulin resistance, reduces risk factors for heart disease and reduces the incidence of death (Oh et al., 2016). Physical exercise also improves weight management, preventing excessive increases in blood pressure over time (Durrani & Fatima, 2015). Adaptation response to physical exercise depends on: frequency, intensity, time, and form of exercise (Saeidi et al., 2022). Previous research suggests that forms of endurance training and strength training can be an alternative in reducing obesity and improving heart health, although resistance training is still considered more effective in improving heart health than strength training (Schroeder et al., 2019). Strength training is thought to have little effect on improving heart health (Shim & Kim, 2017). In contrast, endurance training for reducing the risk of heart disease and increasing parasympathetic activity (Grässler et al., 2021). However, the analysis of the effectiveness of power training and strength training on cardiac performance has not been widely reported. The form of endurance training is still unclear in terms of intensity and duration, compared to strength training which will also increase muscle mass and cause muscle hypertrophy (Machado et al., 2021). Therefore, this study aims to analyze the adaptive response of strength training and endurance training as a physiological modulator in improving cardiovascular health in obese adolescent womens.

Study participants
This study is an experimental study that aims to analyze differences in strength and endurance training as a physiological modulator of improving cardiovascular health in obese adolescent girls. This study involved 24 obese adolescents, female gender, age 20-24 years, body mass index (BMI) 27-35 kg/m 2 , normal oxygen saturation (SpO 2 ). Participants were divided into 3 groups: control, strength training, and endurance training. The division of groups was done randomly, each group of 8 participants. Prior to the study all participants were given an explanation of the research problem and procedure, both written and verbal. All participants, both verbally and in writing, expressed their willingness. Likewise, participants also received an explanation of the physical exercise procedures during treatment.
This study was approved by the ethics committee of the institution and conducted in accordance with the guidelines of the Helsinki Declaration. Informed consent was obtained from all participants.

Study design
Warming up and cooling down, with static and dynamic stretching and running on a treadmill. Light intensity is used for heating and cooling. Each group started at 06.00-10.00 A.M., at the same time on different days. Strength training is done by lifting moderate intensity weights, for 35 minutes. Exercises are performed at intervals, 12 repetitions, 6 sets, with active rest between sets for 30 seconds. While endurance training was done by means of participants running on a treadmill for 35 minutes continuously, with moderate-intensity (60-70% HRmax). Exercise is done 3x/ week for 4 weeks. Heart rate monitored using Polar H10. Physical exercise intervention will be temporarily stopped if physical signs are found, shortness of breath, sharply increased heart rate, dizziness and pale face.
Measurement of heart health using parameters of systolic and diastolic blood pressure and resting heart rate. Measurement of heart health was carried out before exercise and 4 weeks after the last exercise, while measurements of height and weight were carried out before exercise. Blood pressure was measured using an OMRON digital blood pressure meter.

Statistical analysis
Data analysis used the one-way ANOVA, which was followed by the Tukey's Honestly Significant Deference (HSD) post-hoc test, with a significant level of 5%.

Results
Characteristics of research participants, based on the results of descriptive statistical analysis in each group are presented in Table 1 below.
Based on the analysis of participant characteristics: resting heart rate, normal systolic and diastolic blood pressure (Table 1). The characteristics of the participants did not show any significant difference (p ≥0.05). Therefore, if there is a difference in heart health, which in this study used blood pressure and heart rate parameters after exercise, it can be believed to be the effect of the intervention given for 4 weeks. The results of the analysis of physical exercise as a modulator of cardiovascular health, in reducing systolic blood pressure in each group (Figure 1).
Physical exercise as a modulator of cardiovascular health in reducing systolic blood pressure between before exercise    and after exercise in the control group did not show any significant difference (p ≥ 0.05). However, in the treatment group there was a significant difference in systolic blood pressure in both strength training and endurance training (p ≤ 0.001). Systolic blood pressure was lower after exercise than before exercise in both the strength training and endurance training groups (Figure 1 and Table 2). Further analysis of changes in diastolic blood pressure before and after treatment in each group in Figure 2. The data analysis of diastolic blood pressure in the control group between before and after treatment there was no significant difference (p ≥ 0.05). There was a significant . Physical Exercise as a Physiological Modulator of Improving Cardiovascular Health in Obese Women difference in diastolic blood pressure between before and after exercise in the strength training and endurance training groups (p ≤ 0.001). The study also showed that diastolic blood pressure after treatment was lower than before exercise ( Figure 2 and Table 2). Analysis of physical exercise as a modulator of decreasing resting heart rate before and after treatment in each group (Figure 3). Analysis of resting heart rate before treatment and after treatment in the control group, did not show a significant difference (p ≥ 0.05) (Figure 3 Table 2), but there was a significant difference in resting heart rate pretest and posttest in the strength training and exercise groups. endurance (p ≤ 0.001). Our data show that resting heart rate is lower, after strength training and endurance training, than before treatment ( Figure 3 and Table 2). One-way ANOVA analysis of the decrease in blood pressure (systolic and diastolic) and resting heart rate before treatment showed no significant difference (p ≥ 0.05) ( Table 2).

Discussion
The results of this study prove that physical exercise is done properly and regularly, a very important factor for maintaining heart health and fighting various diseases (Souissi et al., 2020). Physical exercise, as the basis for lifestyle change interventions in preventing as heart disease Andarianto et al., 2022;Rejeki et al., 2021). The findings of this study prove that moderate-intensity exercise, frequency 3x/week for 4 weeks, improves cardiovascular health in obese adolescent female participants ( Table 2). The improvement in heart health can be seen from the decrease in systolic blood pressure, diastolic and resting heart rate after strength training and endurance training (Figure 1-3, Table 2). Several previous studies, which are similar to this study, also found that individuals who limit their passive and active lifestyle to physical exercise have normal blood pressure, stable body weight (Durrani & Fatima, 2015), higher cardiac output, blood pressure, lower resting heart rate, higher insulin sensitivity, better plasma lipoprotein profile than someone who is physically inactive (Nystoriak & Bhatnagar, 2018). Research identical to this study also found a decrease in blood pressure and resting heart rate after doing an endurance training program and strength training 3x/week, (Jamka et al., 2021). Research with walking intervention and crossfit exercise on participants in the age group 14 -38 years, significantly lowers blood pressure (Almutawa et al., 2020), also found stronger heart muscle, decreased sympathetic nerve activity and decreased resting heart rate ≤ 60 bpm in marathon runners (Oh et al., 2016). Durrani's research involving 701 participants, children aged 12-16 years, found a relationship between physical activity and blood pressure (Durrani & Fatima, 2015). In another study, someone who did regular physical exercise found a decrease of 20 mmHg in systolic blood pressure and 11 mmHg in diastole (Kui et al., 2022). In addition, physical exercise was found to cardiac morphological changes that will cause aortic diameter widening accompanied by left ventricular fibrosis, improve oxidative profile and metabolic health (Dupuy et al., 2022).
The improvement in cardiovascular health is the effect of exercise adaptation in increasing the promoting increased vasodilation through relaxation of vascular smooth muscle cells. Given this effect, it is important to decrease the activity of Endothelial Nitric Oxide Synthase (eNOS), which contributes to blood pressure (Ramos et al., 2019). Resting heart rate and blood pressure were lower than the control group and before exercise, this shows that exercise is able to modulate changes in the heart system, both in form and function, thereby improving cardiovascular health. Exercise is believed to be a modulation of changes in heart size, as a result of increasing left and right ventricular cavities and increasing the thickness of the heart muscle wall and cardiac septum. Endurance training is believed to be beneficial exercise to improve heart function, such as decreasing heart rate. The heart rate is estimated to decrease by 10-15 bpm, that the individual is able to work hard efficiently (Pinckard et al., 2019).
Our study findings also show that heart rate and blood pressure are lower in endurance training than in strength training. Endurance training in general increases the oxidative ability to meet oxidative demands, the heart will contract and relax, cardiomyocytes and increase the strength of heart contraction, which is more optimal than strength training. The rate of contraction and relaxation requires increased adaptation of the cardiomyocyte contractile system, which is associated with an increase and the rate of intracellular Ca2+ release. Coordination between Ca2+ mediated Ca2+ type L channels and activation of the ryanodine receptor (RyR). This causes an increase in Ca2+ ion sensitivity, resulting in greater force and speed of contraction after exercise (Nystoriak & Bhatnagar, 2018). A decrease in blood pressure and heart rate is a complex event, many factors influence it, an increase in peripheral vascular resistance and autonomic nervous activity is the most important mechanism (Oh et al., 2016).
Improved heart health is strongly suspected to be the effect of endurance exercise, as a modulator of changes in fat mass (Shim & Kim, 2017). Therefore, endurance training is described as the optimal form for reducing the risk of heart disease and increasing parasympathetic activity (Grässler et al., 2021). Previous studies have also reported that endurance training induces greater improvements in cardiorespiratory fitness and cardio-metabolic variables (Schroeder et al., 2019), decreased acute stress reactivity and decreased heart rate and heart rate variability compared to the control group (Arvidson et al., 2020). Strength training also has a modulating effect on cardiac performance, although not as high as resistance training. Strength training, affects the increase in the strength of heart muscle contraction, heart muscle endurance, and reduces damage to the inner walls of blood vessels, to improve blood vessel function (Shim & Kim, 2017). Strength of heart muscle contraction, is the impact of strength training that causes cardiac muscle hypertrophy, skeletal muscle hypertrophy. Hypertrophy causes an increase in stronger contractions and a more complete emptying process in systole, with greater stroke volume and cardiac output (Schroeder et al., 2019). Therefore, both forms of exercise in this study are beneficial for the obese group, in addition to improving cardiovascular health, this exercise is also believed to initiate an increase in muscle mass and decrease fat mass in obesity Sugiharto et al., 2022).
The findings of this study provide a starting point for understanding exercise as a modulator of improved cardiovascular health, and provide a solid foundation for understanding that well-organized exercise causes response and adaptation. Response and adaptation to exercise not only change shape, but also function in all body systems, not only the heart. Although exercise modulation for 4 weeks, in improving heart health may not be optimal. However, training for 4 weeks is the beginning of the adaptation process to the exercise program, as described in the general adaptation of the body. But this research also has limitations, among others the study participants only used one group of obese adolescent girls, on heart health, this study has not measured the parameters of changes in body fat, muscle mass and changes in the endothelium associated with heart health. In addition, they have not been able to fully control the physical activities carried out, outside the exercise program that has been set for 4 weeks. Perhaps the results of this study cannot be generalized to all age groups and genders. However, the findings of this study still have significance in developing the science of exercise physiology, by providing substantial data and information, and opening up opportunities for further research.

Conclusion
Overall, it was concluded that endurance and strength exercise moderate intensity, for four weeks improved cardiovascular health, by decreasing blood pressure and resting heart rate. However, endurance training lowers resting blood pressure and heart rate more than strength training, therefore endurance training can be recommended as a modulator to improve cardiovascular health in obesity.