Effects of inspiratory muscle training on lung function, muscle oxygenation and functional capacity in older adults

Background and objective. Inspiratory muscle training (IMT) generates positive effects on physical performance, but there is little evidence on the effects on muscle resaturation in older adults. The study aimed to assess the impact of a 4-week Inspiratory Muscle Training (IMT) program on peak dynamic inspiratory strength, lung function, muscle oxygenation and functional capacity in functionally independent older adults. Material and methods. Twelve randomized older adults (EG= n6; 68.8 ± 2.6 years; SCG=n6, 71.5 ± 4.7years) completed the study. A 4-week IMT program was applied, along with general physical activity recommendations. Activities of daily living, lung flow and volumes, peak dynamic inspiratory force (S-index), peak inspiratory flow (MIF), muscle resaturation velocity (ΔTSIreoxy) by NIRS and the Senior Fitness Test battery were assessed pre and post intervention. Results. Improvements in the EG in the Chair Stand Test (p=0.013; η²p=0.474), Biceps Curl Test (p=0.015; η²p=0.463) and 6 minutes walking test (p=0.011; η²p=0.495), while in the control group changes were observed only in Biceps Curl Test (p=0.004; η²p=0.589). An increase in EG was observed in the S-Index (p=0.038; η²p=0.363) with a high effect on peak inspiratory flow (MIF) (p=0.138; η²p=0.206), finally EG showed a high effect size on muscle resaturation velocity at the end of exercise (p=0.213; η²p=0.187; Δ=-31%). Conclusions. Short IMT program increases S-index, physical capacity and muscle oxygenation velocity. IMT may be a complementary intervention strategy in older adults to improve their physical fitness and peripheral vascular response.