عنوان مقاله [English]
The aim of the present study was to investigate the effect of a cycling endurance activity on serum concentrations of surfactant D and Clara proteins. The present study was a quasi-experimental study with two stages of pre-test and post-test. The statistical sample of the research was 20 cyclists (elite cyclists = 10 people, recreational cyclists = 10 people) in Tehran province with an age range of 20-30 years. In this study, Clara cell and surfactant D proteins were measured after one session of endurance activity with an intensity of 70-80% of maximum oxygen consumption for 30 minutes. After research interventions, serum levels of Clara cell protein and surfactant D protein were assessed. Data analysis was performed using descriptive statistics (age, height and weight) and inferential statistics (Independent and dependent t-test) using Spss software version 25. Findings showed that the serum concentration of Clara cell after training intervention was significantly increased in both groups of elite and recreational cyclists. Also, serum levels of D-surfactant protein increased significantly after training intervention only in elite cyclists. The results showed that one session of endurance activity may increase the serum levels of Clara and surfactant D proteins in athletes.