available online at http://journal.uny.ac.id/index.php/jolahraga Jurnal Keolahragaan, 11 (2), 2023, p. 248-255 https://doi.org/10.21831/jk.v11i2.65453 This is an open access article under the CC–BY-SA license. Effect of circuit weight training on aerobic fitness, body fat percentage, muscle mass percentage, and hand grip strength in the elderly Intan Suraya Ellyas*, Sunardi, Agus Margono, Sarjoko Lelono, Muhammad Mariyanto, Agus Kristiyanto Faculty of Sports Science, Universitas Sebelas Maret, Jl. Menteri Supeno No. 13, Manahan, Banjarsari, Surakarta, Central Java, 57139, Indonesia * Coressponding Author. E-mail: intan_penkepo@staff.uns.ac.id Received: 28 August 2023; Revised: 3 September 2023; Accepted: 7 September 2023 Abstract: As individuals age, there is a natural decline in physical activity and aerobic capacity, which can have profound effects on their overall health and well-being. The purpose of this study was to determine the effect of weight training using circuit methods on aerobic fitness, body fat percentage, muscle mass percentage, and hand grip strength. This study is a one-group pretest-posttest quasi-experimental study with a sample of the elderly gymnastics group Sehat Bugar Ceria in Karanganyar Regency, Indonesia. Twenty- seven study subjects aged 60–75 participated in the exercise for 12 meetings. All research subjects can take all pretests and posttests in the form of a six-minute walk test, a hand grip strength test using a handgrip dynamometer, and body composition testing using bioelectrical impedance analysis. Changes that occurred before and after exercise were analyzed using paired t-tests. This study showed that aerobic fitness increased significantly (p = 0.001), body fat percentage decreased significantly (p = 0.008), but there was no significant change in the percentage of muscle mass (p > 0.05) or hand grip strength (p > 0.05). The results of this study showed that weight training using circuit methods can improve aerobic fitness and reduce body fat percentage in the elderly group. Keywords: aerobic fitness, fat body mass, weight training, circuit training, elderly How to Cite: Ellyas, I. S., Sunardi, S., Margono, A., Lelono, S., Mariyanto, M., Kristiyanto, A. (2023). Effect of circuit weight training on aerobic fitness, body fat percentage, muscle mass percentage, and hand grip strenght for the elderly. Jurnal Keolahragaan, 11(2), 248-255. doi:https://doi.org/10.21831/jk.v11i2.65453 INTRODUCTION The number of elderly people has increased around the world, including in Indonesia. The number of elderly residents increased by at least 3 percent over more than a decade (2010–2020) to 10.82 percent. Life expectancy also increased from 69.81 years in 2020 to 71.57 years in 2021(BPS, 2022). This condition is a challenge; the increasing number of elderly people should be followed by a good, active, and productive elderly health status. As individuals age, there is a natural decline in physical activity and aerobic capacity, which can have profound effects on their overall health and well-being. In the elderly group, there is an accelerated loss of muscle mass and movement function, causing an increased risk of falls, decreased functional capacity, weakness, and death (Greco et al., 2019). As people grow older, they may experience a reduction in their energy levels, muscle mass, and joint flexibility, making it challenging to engage in regular physical activities (Kang et al., 2021). Sedentary lifestyles become more prevalent, leading to a decrease in aerobic capacity, the ability of the body to utilize oxygen efficiently during exercise. This decline in aerobic capacity can lead to decreased endurance, fatigue, and a reduced ability to perform daily tasks independently (McPhee et al., 2016). Moreover, a lack of physical activity in the elderly population increases the risk of various health conditions, including cardiovascular diseases, obesity, and metabolic disorders. To counteract this decline, it is crucial to promote and encourage regular physical activity tailored to the individual's capabilities (Langhammer et al., 2018). Regular physical activity not only contributes to a healthier and more active lifestyle but also helps preserve independence and quality of life as individuals age.