The effect of smoking on lung function changes during a 16-week combined exercise program in middle-aged workers: a...

To investigate the longitudinal changes in lung function of sedentary middle-aged workers over a 16-week combined exercise training program.

Thirty-six sedentary workers (53.70 ± 6.92 years old) were randomly allocated to either a combined aerobic and resistance training program (n = 18) or a control group (n = 18). Lung function was evaluated through spirometry using a portable flow spirometer (Spiropalm 6MWT, Cosmed, Italy). Predicted percentages of forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁), FEV₁/FVC ratio, and mean forced expiratory flow between 25 and 75% of exhaled FVC (FEF_25-75) were analyzed. Assessments were performed at baseline (M1), after 8-week (M2) and 16-week follow-up (M3). The changes in lung function were analyzed using the Latent Growth Curve Modeling that estimated interindividual and intraindividual growth paths.

Smoking status revealed a significant effect on lung function growth with significant paths to intercept and slope for all models in both groups. The exercise group participants who are non-smokers revealed higher increases in FVC% (β = .22), FEV₁% (β = .08), FEV₁/FVC% ratio (β = .19), and FEF_25-75% (β = .06) compared to those who are smokers from M1 to M3. The control group revealed a lower growth in lung function from M1 to M3, with a lower slope observed in smokers compared to non-smokers for FVC% (β = - .44), FEV₁% (β = -.41), FEV₁/FVC% (β = - .98), and FEF_25-75% (β = - .52).

Our findings suggest that a 16-week combined training program is an effective strategy to improve lung function among sedentary workers, with a higher magnitude of improvement for non-smokers compared to smokers.

Clinicaltrials.gov, NCT04868240. Registered April 30, 2021.