Implications of Airway Resistance and Conductance on the Respiratory Rate in individuals With Various Nutritional States Exposed To Exercise

Erick Sánchez-Peña,1 Sebastián Andres Rodríguz-Valdés,1 Daniel Fernando Donoso-Riveros,1 Máximo Escobar-Cabello,1,2 Mariano del Sol,3,4 Fernando Valenzuela-Aedo,3,4 Rodrigo Lizama-Pérez,5 Rodrigo Muñoz-Cofré3,4 1Department of Kinesiology, Catholic University of Maule, Talca, Chile; 2Laboratory of Ventilatory Dysfunction Function, Department of Kinesiology, University Catholic of Maule, Talca, Chile; 3Center of Excellence in Morphological and Surgical Studies, University of La Frontera, Temuco, Chile; 4Doctoral Program in Morphological Sciences, University of La Frontera, Temuco, Chile; 5Department of Physical Education and Sports, Faculty of Sport Sciences, University of Granada, Granada, SpainCorrespondence: Rodrigo Muñoz-Cofré, Avenida Francisco Salazar &num; 01145 Universidad de La Frontera, Temuco, Chile, 4811230, Email [email protected]: To determine how airway resistance (RAW) and airway conductance (GAW) affect inspiratory time (iT) and expiratory time (eT) in subjects with different nutritional states using the step test.Methods: Forty-eight participants were recruited and divided into three groups: 16 normal weight (NW), 16 overweight (OW), and 16 obese (OB). A lung function test and anthropometric evaluation were performed. iT and eT were measured using a sonographic device before and after the step test.Results: Body Mass Index (BMI) and Body Fat Percentage (BF%) were significantly higher (P< 0.0001; P< 0.0001, respectively) in OB group. RAW was significantly higher in the OB group (P=0.004), and GAW (P=0.004) was significantly lower in the same group. At rest, the Respiratory Rate (RR) was significantly higher in OB group (P< 0.05), while iT and eT showed no significant differences. On the other hand, after the step test, eT was significantly lower (P=0.016), with the multiple linear regression model being the best predictor of post-exercise eT, including BF%/GAW and BF%/sGAW (explained variability of 15.7% and 14.6%, respectively).Conclusion: Nutritional status can significantly impact lung function; at rest, there was a decrease in lung volumes and an increase in RR in OB subjects. In addition, there was a significant decrease in eT of OB subjects post-exercise. Finally, a significant relationship of BF%/GAW and BF%/sGAW with post-exercise eT was noted.Keywords: airway resistance, airway conductance, respiratory time, nutritional states