An investigation of the relationship between lung function and exercise capacity as measured by the incremental shuttle walk test in healthy adults

Abstract

Aim and background: Exercise capacity is mainly influenced by the cardiac function. On the contrary, the impact of the respiratory system on exercise capacity in healthy individuals is controversial. The purpose of this study is to investigate if there is any correlation between lung function and exercise capacity as measured by the incremental shuttle walk test (ISWT) in healthy individuals. The findings may be used for future studies in people with lung conditions and decreased exercise capacity. Methods: An observational cross-sectional design was used. Exercise capacity was assessed through the ISWT in 30 healthy participants (mean age 27). Lung function was measured by Forced Vital Capacity (FVC % predicted), Forced Expiratory Volume in first second (FEV1% predicted), Maximum Inspiration Pressure (MIP) and Maximum Expiration Pressure (MEP). Pearson’s correlation coefficient was conducted to assess the relationship between lung function and the ISWT. Results: There was a significant correlation between FVC % predicted and the ISWT (r= 0.426, p= 0.02). FEV1% predicted was also shown to have a significant relationship with ISWT (r= 0.448, p= 0.01). MEP was found to significantly relate to the ISWT (r= 0.529, p= 0.003). In contrast, there was no significant correlation between MIP and ISWT (r= 0.338, p= 0.07). Conclusion: Exercise capacity positively correlated with lung volumes and MEP. This may enhance our knowledge regarding the limiting factors of exercise capacity and how these parameters can positively affect health status. However, no correlation was found between exercise capacity and MIP and this could be related to the muscles of inspiration which is not a limiting factor of exercise capacity.