Assessment of the Impact of Physical Fitness on Lung Function

Children and young adults who participate in aerobic fitness activities may experience greater lung volumes as adults but not an improvement in airway caliber, according to a study published in the European Respiratory Journal.

Researchers examined data from 2 prospective, population-based, cohort studies, the Odense schoolchild study from Odense, Denmark (n=1369), and the Dunedin Multidisciplinary Health and Development Study in Dunedin, New Zealand (n=837), to determine if there was an association between physical fitness and lung function in children and young adults. Individuals were assessed via a maximal cycle ergometer to test aerobic fitness in the Odense study at ages 9, 15, 21, and 29 years, while those in the Dunedin study were assessed at 15, 26, 32, and 38 years.

Study results demonstrated that physical fitness increased with age up until early adulthood and then began to decline in participants at ages 21 and 26 years in the Odense and Dunedin studies, respectively. Assessment of lung function revealed that forced expiratory volume in 1 second (FEV₁) peaked in early adulthood, with forced vital capacity (FVC) continuing to increase and peak in the Odense and Dunedin studies at ages 29 and 32, respectively. The researchers also performed a cross-sectional analysis that found a statistically significant association between aerobic fitness in FEV₁ and FVC, but not in the FEV₁/FVC ratio. For each standard-deviation improvement in early adulthood fitness, there was a 2%- to 3%-higher percentage predicted value for FEV₁ and FVC. Longitudinally, the study results showed better adult lung function was associated with improvements in fitness during childhood and young adulthood, especially in male participants.

While in general the relationship between fitness and sex was similar between both sexes, male participants at a younger age in the Dunedin study exhibited a stronger association than female participants. In addition, male participants demonstrated stronger associations between changes in fitness and spirometric volumes in both studies and demonstrated better adult lung function with fitness improvements in early childhood and young adulthood. No significant interactions between fitness and smoking were identified in this study after data were adjusted for smoking. These findings were also found to be independent of height and weight, thereby suggesting the improvements are independent of physical growth. The results remained unchanged even when adjusted for asthma, as excluding participants diagnosed with asthma did not alter the results.

The researchers concluded that physical fitness during childhood and young adulthood may improve and enhance lung function in individuals when they reach early adulthood, as this study noted higher values of FEV₁ and FVC in participants who engaged in aerobic fitness during childhood and young adulthood. The researchers found these improvements decrease with age and are no longer significant once adulthood/older age is reached. Therefore, clinicians should encourage children and adolescents to participate in aerobic exercise and physical fitness activities on a regular basis, as they are strongly associated with enhanced peak lung function in early adulthood.

Reference

Hancox RJ, Rasmussen F. Does physical fitness enhance lung function in children and young adults [published online January 31, 2018]? Eur Respir J. doi: 10.1183/13993003.01374-2017