Author(s): TAGLIAPIETRA, G., PRIMAVESI, J., POCHON, J., TRAMBATY, T., NEYROUD, D., DAUCOURT, C., POMPILIO, P.P., BAGGISH, A.L., Institution: UNIVERSITY OF LAUSANNE, Country: SWITZERLAND, Abstract-ID: 2559

INTRODUCTION:
Lung function declines with age in the absence of disease (Verleden et al. 2021; Schneider et al. 2021). Specifically, impairments in small airway function and increased lung parenchymal stiffness have been observed in older adults compared to younger individuals (Sicard et al. 2018). However, the acute effects of exercise on lung mechanics remain underexplored in this population. The aim of this study was to examine the combined effect of duration and intensity on respiratory resistance (Rrs), reflecting the resistive characteristics of the respiratory system, and reactance (Xrs), an index of the elastic properties of the airways, in older adults.
METHODS:
Men and women (inclusion age 65-80) completed an incremental treadmill test to volitional exhaustion, during which heart rate (Frontier X2, Fourth Frontier, USA) and pulmonary gas exchange parameters (Quark CPET, COSMED, Italy) were continuously monitored. On separate visits, participants performed a 10 min exercise bout at workloads corresponding with VT1-15% (session 1, moderate intensity domain) and a 30 min exercise bout at VT1+15% until volitional exhaustion (session 2, heavy/severe intensity domain) on a treadmill. Lung mechanics were assessed pre- and post-exercise during tidal breathing using an oscillometer (FIRST, RESTECH Italy) at 5 Hz according to international standards (King et al. 2020).
RESULTS:
Five women and three men (age range: 66-73 yr, height: 169 ± 8.7 cm, BMI: 23.7 ± 1.8 kg/m2) completed both the incremental treadmill test to volitional exhaustion (V̇O2-PEAK = 35.1 ± 5.3 mL·kg⁻¹·min⁻¹, peak heart rate = 170 ± 9 bpm, V̇O2-VT1 = 24.3 ± 5.6 mL·kg⁻¹·min⁻¹) and the two experimental exercise bouts. The average heart rate during the two sessions differed significantly (session 1 = 61.4 ± 4.4% vs. session 2 = 83.1± 7.3% of the HRpeak; p < 0.001). In this context, there were significant across session differences in the pre-to-post exercise changes in the inspiratory component of Xrs (session 1 = 0.057 ± 0.062 vs. session 2 = -0.065 ± 0.161 cmH2O·s/L; p = 0.040) indicating a decrease in lung parenchymal stiffness only after the longer and more intense bout of exercise. We postulate that the greater metabolic demand and associated hyperventilation induced by session 2 promoted mechanical stretching of the peripheral airways leading to airway smooth muscle relaxation and transient bronchodilation (Pellegrino et al., 1999). A confirmatory trend toward a decrease in the inspiratory component of the Rrs was observed from pre to post exercise during session 2 (1.92 ± 0.81 vs. 1.80 ± 0.65 cmH2O·s/L; p = 0.160).
CONCLUSION:
Initial findings suggest a transient improvement of peripheral airway compliance following prolonged heavy intensity but not shorter duration moderate intensity exercise in healthy older adults. Larger studies are required to confirm these observations and to isolate the impacts of sex, age, and exercise intensity / duration on pulmonary mechanics.