EIGHT SESSIONS OF HIGH INTENSITY INTERVAL PHYSICAL EXERCISE LOWERING THE STOMACH CIRCUMFERENCE OF OBESE ADULT WOMEN SEDENTER

Sedentary lifestyle is a lifestyle that is associated with an unhealthy diet and lack of physical activity. The study aimed to analyze high-intensity physical exercise at interval intervals (HIIT) for changes in resting pulse and abdominal circumference in overweight young adult women with sedentary lifestyle. Subject is a lot of 20 people aged 21-30 years into 2 groups. The treatment group by performing HIIT and the control group without performing HIIT. Physical exercise with an intensity of 90% of the axial heart rate (HRmax), at intervals. Exercise is done by pedaling ergocycle for 10 seconds at a speed of 100 rpm and 50 seconds with speed 50 rpm, done alternately (intervals), with a total time of 20 minutes. Exercise is done 3x /week or as many as 8 sessions in 3 weeks. The data in this study was taken before and after treatment, in the form of a resting pulse (HR rest) and stomach circumference (LP) measured in position parallel to the navel. The results showed that there was no significant difference in the average value of HR rest between groups (p≥0.05), while LP indicated that there was a significant decrease in the HIIT group (p<0.05). The conclusion in this study is that HIIT effectively lowers the stomach circumference of the treatment group and also has a tendency to decrease the average HR rest.


INTRODUCTION
Sedentary lifestyle is a lifestyle that is associated with an unhealthy diet and lack of physical activity. Sedentary lifestyle can trigger an increased buildup of body fat accumulation, which can increase the risk of dyslipidemia (Ma, Sahar, Jeong, &Huh, 2019;Mamikutty et al., 2014;Moreno-Fernández et al., 2018;Rask Larsen, Dima, Correll, & Manu, 2018). Sedentary lifestyle in individuals with overweight will affect the decline of the cardiovascular system, decreased muscle strength and flexibility that causes muscle elasticity to decrease, thereby increasing the occurrence of injury (Nuzzo, 2019).
World Health Organization (2016) data 25.68% of the world's population or >1.9 billion people are overweight. In 2016, 13% of the world's population or 650 million people with >18 years of age were obese with a greater prevalence of women of 4% than men. In Indonesia, the prevalence of overweight (BMI ≥25.1-27kg/m2) increased annually with prevalence of 8.6% in 2007, 11.5% in 2013, and 13.6% in 2018. Meanwhile, the prevalence rate of obesity (BMI >27) was 10.5% in , 14.8% in 2013and 21.8% in 2018(Riskesdas, 2018. In addition, if the cycle of obesity occurs repeatedly in the same individual as sarcopenia,then the risk factors for metabolic syndrome attacks will also be higher (Ma etal., 2019). The risk of metabolic syndrome is one of them due to the activation role of the sympathetic nervous system which contributes to improved heart function that stimulates vasoconttion in blood vessels causing blood pressure to rise (Bastien et al. , 2014;Hall et al. , 2016) . In addition, metabolic balance is also unstable, such as excess lipolysis that can move fatty acid levels so as to interfere with blood vessels and heart function (Ciccarelli etal., 2013). Thus patalogis symptoms in general will appear with the characteristics of increased blood pressure (hypertension), increased plasma triglycerides, plasma glucose, as well as disturbances in insulin resistance that lead to an increased risk of CVD disease, stroke, and diabetes (Han & Lean, 2016;Pescatello, 2014). If this continues to happen, it will have an impact on the quality of public health that is decreasing.
One method that can be done to overcome the problem is through physical exercise. Physical exercise has been shown to improve fitness and cardiovascular  (Palaparthi, 2017). HIIT (High Intensity Interval Training) is a physical exercise that combines high intensity and combined with moderate intensity / low in stead (Stöggl & Björklund, 2017). Thompson (2019) HIIT is also very popular by the public, proven because it has become the number 3 physical exercise trend worldwide.
HIIT also improves cardiovascular function by lowering resting pulse rates in obese individuals (Huang, Shi, Davis-Brezette, &Osness, 2005). HR rest, or commonly called a resting pulse is one indicator of physical fitness, this is because HR rest or resting pulse will be lower and the heart rate reserve will be higher showing a good cardiovascular fitness level in individuals (Gillen et al., 2016). In the research conducted (Ahmadizad, Avansar, Ebrahim, Avandi, & Ghasemikaram, 2015;Weston, Wisløff, & Coombes, 2014) showed that HIIT causes a significant reduction in body fat percentage and abdominal circum ference.
Thus, HIIT is a recommended and beneficial training method for improving fitness and cardiovascular health. However, the effectiveness of HIIT with ergocycle conducted by obese adult female subjects with sedentary lifestyle is still unknown, so research related to HIIT on changes in resting pulse and abdominal circumference.

METHOD
The research done is experimental research. This research design uses pretest design and posttest control group design,which is where there is data retrieval before treatment and after treatment. There were two groups in the study: the experimental group that was given the treatment of high-intensity physical exercise at intervals (HIIT) with ergocycle and a control group without intervention.
The study subjects were women categorized in over weight body mass index (BMI) in Asia Pacific 23-24.9, ages 21-30 years, and sedentary lifestyle category.
The large sample in this study was 10 people in the control group and 10 people in the HIIT group. The HIIT protocol is high-intensity physical exercise that is 90% maximum pulse rate (HRmax) at intervals. Physical exercise uses ergocycle for 10 seconds at a speed of 100 rpm and 50 seconds with speed 50 rpm, done alternately (intervals), for a total time of 20 minutes. Exercise is done 3x / week or as many as 8 sessions in 3 weeks.
The data in this study was taken before and after being giventreatment, in the form of resting pulse (HR rest) and stomach circumference (LP),as wellas changes from HR rest and LP, obtained from the calculation of data difference. after subtracting the data before. The circumference of the stomach is measured in a position parallel to the navel.
Data analysis is done with the help of SPSS software. Data is analyzed descriptively. The normality and homogeneity test is carried out. Data that is distributed normally and homogeneously, then conducted different tests between groups using independent T-tests, and different tests between data before (pre) and after (post)intervention in the group that It's the same with the T-test pair.

RESULT
The data of the study results in the form of resting pulse data (HR rest) in units of beat per minute (bpm) or number of beats per minute and stomach lingkap (LP) in cm units.Data consists of pre(before) intervention and post (after) intervention.   ^sig. difference (p<0.05) between pre &post in the same group (Paired T test). *sig. difference (p<0.05) between groups (Independent T test).

Discussion High Intensity Interval Training on Resting Pulse
Based on the results showed that there was no significant difference in the effect on the average value of HR rest on CONTROL and HIIT. The insignificant decrease in HR rest in this study was likely due to the study time being too short, which was only 2 weeks. According to Reimers et al (2018) the effect of physical exercise on HR Rest can be a significant change if done for at least 3 months with 3 sessions per week.
Nonetheless, the HIIT group had a higher hr rest impairment value compared to CONT. This is in line with a meta-analysis by Huang et al (2005) which proved that 13 studies showed that physical exercise with aerobic type performed chronically in subjects with ≥60 years can reduce HR rest by 8.4%. In addition, research from Heydari et al (2012) also stated the same thing, in the study mentioned that high intensity intermittent exercise (HIIE) conducted in overweight men for 12 weeks showed a significant decrease in heart rate, as well as increasing fitness levels by 17%. Decreased HR rest after routine HIIT is possible due to the occurrence of induction in increased stroke volume (Heydari etal., 2012). The increase in stroke volume will increase plasma volume thus increasing myocardial contractile which leads to a decrease in HR rest (Helgerud et al., 2007). A normal decrease in HR rest certainly has many health benefits such as lowering the risk of developing cardiovascular disease, high cholesterol and triglycerides, and hypertension (Sharashova etal., 2015).

High Intensity Interval Training on Abdominal Circumference
Based on the results of the study in figure 2 there was a significant difference in the HIIT group. It is clear that there was a decrease in pretest-posttest abdominal circumference in the HIIT group. In contrast, in the control group there was an increase