Body Mass Index Linked to Lung Function, Physical Activity Shows No Significant Effect
A 2026 study by Hana Fajrin Kamilia and Eveline Margo from Universitas Trisakti, Indonesia, reports that body mass index (BMI) is significantly associated with lung function, while physical activity shows no measurable impact. Published in the International Journal of Integrative Sciences (IJIS), the research examines Peak Expiratory Flow (PEF) among healthy adults and highlights the role of body composition in respiratory performance—an increasingly relevant issue in sedentary urban lifestyles.
The findings matter because lung function is a key indicator of overall health, yet it is often overlooked in working-age populations. As more adults spend long hours in low-activity environments, understanding the factors that influence respiratory capacity becomes critical for prevention and early detection of health risks.
Background: Sedentary Lifestyles and Respiratory Health
Peak Expiratory Flow (PEF) measures the maximum speed of air expelled from the lungs after a deep breath. It is widely used as a simple tool to assess lung function and detect early respiratory issues.
Modern work patterns, particularly in academic and office settings, are dominated by prolonged sitting and limited physical movement. This shift has raised concerns about declining physical fitness, including respiratory health. While physical activity is generally believed to improve lung function, and BMI is often linked to respiratory outcomes, previous studies have produced mixed results.
The study by Hana Fajrin Kamilia and Eveline Margo from Universitas Trisakti addresses this gap by examining both variables simultaneously in a real-world adult population.
Methodology in Simple Terms
The research used a cross-sectional design conducted between September and October 2025. A total of 57 healthy adults—comprising lecturers and administrative staff—participated in the study.
Data collection involved straightforward methods:
- Physical activity levels were assessed using the International Physical Activity Questionnaire (IPAQ-Short Form)
- BMI was calculated based on measured height and weight
- Lung function was evaluated using a peak flow meter, with the highest result from three attempts recorded
The researchers then applied statistical analysis to determine whether physical activity and BMI were related to PEF.
Key Findings
The study reveals a clear pattern in both lifestyle and health indicators among participants:
- 73.7% of respondents had low physical activity levels
- 59.6% showed low PEF values, indicating reduced lung function
- 63.1% were classified as overweight or obese
When examining relationships between variables:
- Physical activity showed no significant relationship with lung function
- Statistical result: p = 0.611
- BMI showed a significant relationship with lung function
- Statistical result: p = 0.026
Further breakdown shows:
- 55.6% of overweight-obese individuals had normal PEF values
- Only 26.7% of individuals with normal or low BMI had normal PEF
These results indicate that BMI plays a more prominent role than physical activity in influencing PEF within this population.
Interpreting the BMI Effect
At first glance, the finding that higher BMI is associated with better lung function may seem unexpected. However, the researchers provide a physiological explanation.
In healthy adults of productive age, higher BMI does not always reflect excess body fat. It can also indicate greater muscle mass, including respiratory muscles such as the diaphragm and intercostal muscles. Stronger muscles can generate higher airflow during exhalation, leading to improved PEF values.
An academic paraphrase attributed to the authors explains: Hana Fajrin Kamilia and Eveline Margo from Universitas Trisakti note that increased BMI in healthy individuals may reflect stronger respiratory muscle capacity, which contributes to higher peak expiratory flow.
Conversely, individuals with lower BMI may have less muscle mass, potentially limiting their ability to produce strong expiratory airflow.
Why Physical Activity Was Not Significant
Despite expectations, physical activity did not show a measurable impact on lung function in this study. Several factors may explain this outcome:
- Most participants engaged in low-intensity physical activity, which may not significantly improve lung capacity
- Physical activity data were self-reported, introducing potential inaccuracies
- The sample size was relatively small
- PEF measurements depend on maximum effort, which can vary between individuals
The findings suggest that not all physical activity contributes equally to respiratory health. Higher-intensity or targeted exercise may be necessary to produce measurable improvements.
Real-World Implications
The study offers practical insights for multiple sectors:
- Individuals: Maintaining a healthy body composition, including adequate muscle mass, may support better lung function
- Workplaces: Sedentary environments should incorporate wellness programs that address both physical activity and nutrition
- Healthcare providers: PEF can serve as a simple screening tool for early detection of respiratory decline
- Policymakers: Public health strategies should emphasize balanced nutrition alongside physical activity
The high percentage of participants with low PEF also underscores the need for routine respiratory health monitoring, even among individuals who appear healthy.
Limitations and Future Research
The authors acknowledge several limitations:
- BMI does not distinguish between fat and muscle mass
- External factors such as smoking and air pollution were not fully controlled
- Physical activity was measured through self-reporting
Future research is expected to use more precise tools, such as body composition analysis and wearable activity trackers, to provide deeper insights into the relationship between lifestyle and lung health.
Author Profile
Eveline Margo, Universitas Trisakti
0 Komentar