The impact of physical activity level, degree of dyspnoea and pulmonary function on the performance of healthy young adults during exercise.

Background: In addition to being simple and requiring minimal technology, the 6-min walk test (6MWT) has been found to be reproducible and well tolerated since its first use. However, the impact of non-anthropometric factors on functional capacity is less clear in healthy young adults because the majority experience no age-related changes in the locomotor system or associated comorbidities.

Aim: To identify the effect of physical activity level, degree of dyspnoea and pulmonary function on functional capacity, evaluated through the 6-min walking distance (6MWD) of healthy young adults, in order to prevent clinical abnormalities.

Method: This is a cross-sectional study including 190 healthy young adults who were subjected to the 6MWT to assess walking distance and degree of dyspnoea using the Borg scale. Furthermore, pulmonary function using spirometry and physical activity level using the International Physical Activity Questionnaire (IPAQ) were assessed. According to the IPAQ, the subjects were categorised as sedentary, irregularly active or active.

Results: The 6MWD was positively correlated with pulmonary function parameters (P ≤ 0.002 for all parameters). There was a marginally significant correlation between the 6MWD and the difference between the scores assessed before and after the test using the Borg scale. There was a trend towards significant differences in 6MWD according to the IPAQ categories. Furthermore, forced vital capacity was the only pulmonary function parameter with significant differences between IPAQ categories (P = 0.02).

Conclusion: In healthy young adults, greater pulmonary function indicates a greater 6MWD. In these subjects, physical activity level based on the IPAQ categories clearly affects pulmonary function. However, the IPAQ category and degree of dyspnoea are poorly related to the 6MWD of these subjects.