Validity Reliability and Standard Norm of Multistage Fitness Test for Measuring the Cardiorespiratory Endurance of the Junior High School Students Located in Kudus Regency

This research aims to: (1) assess the validity of the Multistage Fitness Test for measuring cardiorespiratory endurance of the junior high school students located in Kudus Regency, (2) evaluate the reliability of the Multistage Fitness Test for this population, (3) establish standard norms for the Multistage Fitness Test, and (4) analyze the cardiorespiratory endurance results of junior high school students using the developed standard norms. This research employed a descriptive quantitative design utilizing a survey methodology. The research participants consisted of junior high school students from Kudus Regency. The sample consisted of 249 students selected through stratified sampling. This research utilized the Multistage Fitness Test as its data collection instrument. This research employed a validity test through Pearson correlation analysis, a reliability test via Intraclass Corelation Coefficient correlation, and established standard norms using average values and standard deviations. The research concludes that: (1) the validity coefficient of the Multistage Fitness Test is at -0.990, categorizing it as very high, and (2) the reliability test of the Multistage Fitness Test is at 0.98, placing it in the high category, thus confirming its suitability as an instrument for measuring cardiorespiratory endurance of the junior high school students in Kudus Regency. (3) The Multistage Fitness Test gains five standard norms: ≥ 42.60 (very good); 35.37 < 42.60 (good); 28.14 < 35.37 (moderate); 20.91 < 28.14 (poor); and ≤ 20.91 (very poor). Consequently, each student's test result can be classified into one of the categories. (4) The results of the student's cardiorespiratory endurance test can be determined based on established standard norms. The distribution of categories is as follows: very good at 9%, good at 22%, moderate at 33%, poor at 34%, and very poor at 2%. It can be concluded that junior high school students in Kudus Regency show the cardiorespiratory endurance categorized as poor than optimal.