Physiological effects of gastrocnemius muscle exercise on cardiopulmonary fitness in students

Physical fitness supports health and productivity among students, who are often prone to reduced physical activity. Strengthening the gastrocnemius muscle may enhance lower limb performance and cardiorespiratory fitness. This quasi-experimental study used a pretest-posttest design without a control group involving 60 purposively selected students of Universitas 'Aisyiyah Yogyakarta. The intervention consisted of gastrocnemius muscle exercises performed over four weeks. Physical fitness was measured using the Harvard Step Test, and data were analyzed using the Wilcoxon Signed-Rank test. There was a significant improvement in fitness scores after the intervention (p = 0.000), with the mean increasing from 23.39 to 51.45, indicating better cardiorespiratory endurance and lower limb efficiency. Discussion: Regular gastrocnemius exercise improves physiological performance through musculoskeletal and cardiovascular adaptations. Conclusion: Gastrocnemius muscle training is an effective and practical method to enhance student physical fitness. Research Contribution: This study provides evidence for the role of targeted muscle exercise in improving physiological and cardiorespiratory function among young adults.