Effects of deep breathing exercise on pulmonary function, perceived stress and physical fitness among healthy smokers

Background: smoking cessation is the most effective strategy to reduce smoking-related health risks, not all smokers are ready or able to quit immediately given the known benefits of deep breathing exercises on lung function, stress reduction, and physical fitness. Objective: to evaluate the effects of deep breathing exercises on lung function, perceived stress, and physical fitness in healthy smokers. Method: A randomized controlled trial was conducted from June 2023 to December 2023. Twenty-six male smokers (20–30 years) with at least 5 years of smoking history were randomly divided into an experimental group, which received pursed lip breathing, diaphragmatic breathing, and powered breathing exercises for 6 weeks, and a control group without any intervention. A spirometer was used for pulmonary function, a perceived stress scale for stress, a six-minute walk test for physical fitness, and chest expansion, and Pittsburgh sleep quality index (PSQI) for sleep quality. Assessment was done at baseline after the second, fourth, and sixth weeks. Result: The mean age of participants was 22.77±0.46 years, smoking duration was 6.80±0.36 years, and BMI was 23.93 ± 1.23. Baseline comparisons revealed no significant differences (p≥0.05) in FEV1, FVC, FEV1/FVC, PSS, and CE between groups; however, significant differences were observed in PEF, 6MWT, and PSQI (p<0.05). Following intervention, significant improvements (p<0.05) were noted in FEV1 and FVC at the 2nd, 4th, and 6th weeks in the experimental group. MANCOVA analysis for controlling the baseline differences, showed significant group differences in PSQI (p<0.001), PEF (p = 0.001), and 6MWT (p<0.001). Conclusion: Deep breathing exercises positively affected lung function, perceived stress, and physical fitness in healthy smokers. Keywords: Smoking, deep breathing exercises, pulmonary function, perceived stress, and physical fitness