i-Core: International Journal of Sport Science

The Contribution of Physical Literacy in Physical Fitness among Different Age Groups

2026-05-21T12:11:55+00:00

The current decline in physical fitness levels across various age groups poses a serious challenge to global public health. Efforts to improve fitness often focus solely on physical exercise, without considering the underlying psychological and cognitive foundations. This study aims to analyze the contribution of physical literacy components—including motivation, self-confidence, and physical competence—to an individual’s level of physical fitness. This study employs a quantitative descriptive approach using a survey method. Data were collected through a standardized physical literacy assessment instrument and field physical fitness tests. The sample was selected using purposive sampling to obtain a representative picture of various age groups. Data analysis was conducted using correlation and linear regression tests to determine the extent to which physical literacy influences fitness status. Key findings indicate that physical literacy has a significant influence and is positively correlated with physical fitness. Individuals with high physical literacy demonstrate more consistent participation in routine physical activities. Motivation and self-confidence act as key drivers in maintaining physical engagement, which ultimately impacts improvements in fitness components such as cardiorespiratory endurance and muscle strength. Physical literacy is not merely a motor skill but an essential prerequisite for achieving a sustainable healthy lifestyle. Curriculum transformations in physical education and community sports programs must prioritize the development of physical literacy to foster a holistically fit society.

The Accuracy of the Open Smash in Volleyball Players

2026-05-21T12:30:22+00:00

This study examines the accuracy of open smashes among Manunggal volleyball players in Jepara Regency. In today’s modern era, many children prefer advanced technological devices over games—such as volleyball. In volleyball, there are several types of hits that can be learned and must be mastered in order to play the sport well and correctly. In volleyball, the playing methods consist of attacking and defending against attacks. In the pursuit of excellence in the sport of volleyball, the smash is one of the most frequently used attacking techniques to score points. A smash is a hit where the hand makes full contact with the top of the ball, causing it to travel at high speed. Since volleyball is a fast-paced game, attacking techniques are more dominant than defensive ones. The objective of this study is to determine the accuracy of the open smash among Manunggal Jepara players.

The Effect of Caffeine on VO2max in Adolescent Athletes

2026-05-21T15:02:37+00:00

VO2max is the maximum amount of oxygen per minute that an athlete uses during exercise. The higher an athlete’s VO2max, the higher their fitness level and performance. Factors influencing VO2max levels include genetics, age, gender, body composition, nutritional intake, and duration of training. Proper nutritional intake can improve lung and muscle endurance and delay fatigue in athletes over extended periods. Caffeine consumption has a stimulating effect on the central nervous system. To date, many athletes consume caffeine as a stimulant to enhance performance. The objective of this study is to determine the effect of caffeine on VO2max in adolescent athletes. The method used in this study is a Systematic Literature Review (SLR). Articles were collected via Google Scholar, PLOS ONE, and PubMed journals related to the effects of caffeine on VO2max values in adolescent athletes, published between 2015 and 2025 in English and Indonesian, yielding 244 relevant articles. The results from the selected articles indicate a significant effect of caffeine administration on VO2max values in adolescents. Both low and moderate doses of caffeine have an effect. However, the greatest increase in VO2max occurs when caffeine administration is adjusted according to body weight.

The Impact of Cold Water Immersion Duration on Heart Rate and Blood Pressure

2026-05-21T15:18:35+00:00

One of the most commonly used recovery methods among athletes is Cold Water Immersion (CWI). The duration of immersion affects the body’s response. However, the effects of varying CWI durations on heart rate and blood pressure—key indicators of recovery—have not been extensively addressed in previous studies. This study aims to determine the effect of CWI duration on heart rate and blood pressure following soccer training. The method used was a true experimental pretest-posttest control group design. The study subjects were soccer players from the “Diklat Diponegoro Muda” team aged 15–18 years. The players were divided into three groups using simple random sampling: 5-minute CWI (n = 11), 10-minute CWI (n = 11), and a control group (n = 15). The primary data collected were systolic blood pressure, diastolic blood pressure, and heart rate. Systolic blood pressure showed no significant differences. Diastolic blood pressure and heart rate showed significant differences, with the 10-minute CWI group exhibiting the most significant effects. CWI duration had a significant effect on diastolic blood pressure and heart rate, but not on systolic blood pressure. A 10-minute CWI had a greater effect than a 5-minute CWI and the control group. Soccer players can perform a 10-minute CWI at a temperature of 15–20°C to achieve significant results.

The Role of Physical Activity in Controlling Blood Glucose Levels in Patients with Type 2 Diabetes Mellitus

2026-05-21T15:43:46+00:00

Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels and is an incurable disease; one way to control blood sugar levels is through physical activity, as it can reduce insulin resistance. This study aims to summarize the results of clinical trials examining the role of physical activity in controlling blood sugar levels in patients with type 2 diabetes mellitus. This study employed a Systematic Literature Review design conducted on Google Scholar, identifying 7 journals for the literature review. Of the 7 journals examined, 6 studies demonstrated a relationship between physical activity and blood glucose levels in patients with diabetes mellitus, while one article did not show a relationship between physical activity and blood glucose levels in patients with diabetes mellitus. Most of the physical activities performed by the respondents were divided into three categories: light activities, such as sleeping, watching television, eating, and performing general household chores; Moderate activities, such as leisurely walking, driving, or using public transportation. Heavy activities, such as gardening, jogging, and intense exercises like sit-ups, push-ups, or cycling. Thus, physical activity can improve insulin sensitivity and aid the process of glucose uptake into cells, thereby lowering blood glucose levels; physical activity also helps reduce the risk of complications such as diabetic neuropathy in patients with Diabetes Mellitus.