Assessment of Respiratory Dysfunction in Obesity and the Use of IMT.

Respiratory function testing (spirometry) will be performed in accordance with the guidelines of the American Thoracic Society and the European Respiratory Society. The respiratory function test will include the following parameters: forced vital capacity (FVC)[FVC in liters], forced expiratory volume in one second (FEV1) [FEV1 in liters], peak expiratory flow (PEF)[PEF in liters/second], vital capacity (VC) [VC in liters], maximum expiratory flow at 25%, 50% and 75% FVC (MEF 25-75%) [MEF 25-75% in liters], maximal inspiratory flow (MIF50) [MIF in liters], maximal expiratory Flow at 50% of vital capacity (MEF50) and maximal inspiratory flow at 50% of vital capacity (MIF50) (MEF50/MIF50) [MEF50/MIF50 in liters].

Respiratory Muscle Strength (PImax/PEmax) by assessing maximum inspiratory pressure (PImax in kilopascal,kPa) and expiratory pressure (PEmax in kilopascal,kPa).

This measurement is to evaluate the potential effect of the intervention on the strength of inspiratory and expiratory muscles, particularly the potential to improve respiratory muscle performance and enhance overall ventilatory capacity in individuals with reduced respiratory muscle strength.

respiratory mechanics parameter: resistance (Rrs)[Rrs in kPa·s·L-¹], reactance (Xrs) [Xrs in kPa·s·L-¹], resonant Frequency (Fres): The frequency where Xrs = 0 (reactance cancels out).

This measurement is to evaluate the potential effect of the intervention on airway resistance and reactance, particularly the potential to improve lung mechanics and detect subtle changes in airway function in individuals with impaired or fluctuating respiratory function.

inflammatory cytokine profile and CRP (IL-1β, IL-6, IL-8, IL-10, IL-12, TNF-α, CRP), lipid profile.

Systemic inflammation parameter and lipid profile, this measurement is to evaluate the potential effect of the intervention on inflammatory status, particularly the potential to modify circulating cytokine levels and acute-phase response markers. Laboratory analyses will be performed by qualified diagnostic personnel. Blood samples will be collected into plasma separator tubes (containing lithium-heparin gel), centrifuged, and analyzed. The following parameters will be used for the assessment: interlukin-1β, interlukin-6, interlukin-8, interlukin-10, interlukin-12, tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), lipid profile (HDL, LDL, TG). The study will be performed once in all study participants and a second time in those undergoing inspiratory muscle training to assess changes in systemic inflammation associated with the intervention.

Body composition parameter - this measurement assesses: Total Body Water (TBW) [TBW in Liters], Fat-Free Mass (FFM) [FFM in Kilograms], Fat Mass (FM) [FM in Kilograms], Body Fat Percentage (%) in Percentage (%), Height (H) [H in Centimeters], Weight (BW) [BW in Kilograms].

Quality of life parameter - WHOQOL-BREF. This measurement aims to assess participants' perceptions of their quality of life in the physical, mental, social, and environmental areas, in particular the potential to improve the overall well-being and daily functioning of individuals undergoing intervention. The numerical score in each domain reflects individual perceptions of quality of life. Scores are determined on a five-point scale, with a possible range of 4 to 20 points in each domain. The higher the score, the higher the quality of life.

Physical activity parameter. This measure aims to assess participants' physical activity levels, specifically the potential to increase overall activity, reduce sedentary behavior, and monitor changes in daily movement patterns in individuals undergoing the intervention. In IPAQ-SF, physical activity level is measured in MET units (MET - Metabolic Equivalent of Task) [MET - min/week]. High physical activity level is >3000 MET-min/week, moderate is 600-3000 MET-min/week, and low is <600 MET-min/week.