Pulmonology & Critical Care
RCT
● RCT
Small COPD study finds different breathing exercises affect muscle oxygen differently
Physiotherapy research international : the journal for researchers and clinicians in physical therapy
Published April 1, 2026
Borges Natália Mota da Silva, Lima Dyego Tavares de, Morais Arthur Bruno de Abreu, Tenório Laura Nat…
Researchers conducted a small study with 29 people who have Chronic Obstructive Pulmonary Disease (COPD). They wanted to see how two different types of breathing muscle training exercises affect oxygen levels in arm muscles immediately after doing them. One exercise was high-intensity, and the other was lower-intensity endurance training. They compared these to a sham, or fake, exercise protocol.
The study found that the high-intensity breathing exercise was linked to a shorter time before oxygen levels in the arm muscle started to drop. In people with more severe COPD, this high-intensity exercise was also linked to a faster rate of oxygen drop compared to the other exercises, but this particular result was not statistically significant. The lower-intensity endurance exercise was linked to different final oxygen saturation levels.
The main reason to be careful is that this was a very small study that only looked at what happened right after the exercises. The authors suggest that high-intensity breathing exercises might reduce blood flow to arm muscles more quickly, especially in people with advanced COPD. However, because the study is small and the findings for severe COPD were not statistically strong, more research is needed. Readers should understand this as early information showing that not all breathing exercises might have the same immediate effect, and that exercise plans should be personalized with a healthcare provider.
View Original Abstract ↓
BACKGROUND AND PURPOSE: Chronic Obstructive Pulmonary Disease (COPD) is a pulmonary condition characterized by airflow obstruction, which progresses with systemic alterations such as changes in muscle composition and metabolism, anticipating the activation of the inspiratory metaboreflex. This study aimed to analyze the acute effects of Inspiratory Muscle Training (IMT) on peripheral muscle metabolism in individuals with COPD, using near-infrared spectroscopy (NIRS).
METHODS: This randomized, blinded, crossover study included 29 individuals with COPD who underwent three distinct sessions: high-load IMT (IMT-Strength, 60% of maximal inspiratory pressure-MIP), low-load IMT (IMT-Endurance, 30% of MIP), and a sham protocol. Tissue oxygenation of the gastrocnemius muscle was assessed using NIRS before and after each protocol.
RESULTS: Differences in mean final tissue oxygen saturation were observed only during the IMT-Endurance protocol. The oxygen desaturation time was shorter during the IMT-Strength protocol compared with the other groups. Although not statistically significant, patients with more severe COPD (GOLD 3-4) exhibited an oxygen desaturation rate higher during the strength IMT compared with the endurance and sham protocols.
CONCLUSIONS: Acute high-intensity IMT may accentuate the reduction in peripheral perfusion, especially in patients with advanced COPD, suggesting possible metaboreflex activation. Conversely, endurance IMT may improve peripheral perfusion. These findings reinforce the need for careful and individualized prescription of IMT in the COPD population.
TRIAL REGISTRATION: Clinical Trials number: NCT06827379 https://clinicaltrials.gov/study/NCT06827379.
