Low-load blood flow restriction strength training in patients with COPD: a randomised single-blind pilot study

Area of Science:

• Pulmonary Rehabilitation
• Exercise Physiology
• Cardiorespiratory Fitness

Background:

• Chronic Obstructive Pulmonary Disease (COPD) significantly impacts physical function and quality of life.
• Pulmonary rehabilitation programs aim to improve exercise capacity and reduce symptoms in COPD patients.
• Optimizing exercise interventions within pulmonary rehabilitation is crucial for patient outcomes.

Purpose of the Study:

• To compare the effectiveness of lower limb low-load blood flow restriction training (LL-BFRT) versus high-load strength training (HL-ST).
• To assess the impact of these training methods on leg strength in COPD patients undergoing pulmonary rehabilitation.
• To evaluate secondary outcomes including functional capacity, physical activity, and symptom burden.

Main Methods:

• Randomized controlled trial involving 30 COPD patients assigned to LL-BFRT or HL-ST for 24 sessions.
• LL-BFRT utilized 30% 1-repetition maximum (1-RM) with 70% arterial occlusion pressure; HL-ST used 70% 1-RM.
• Primary outcome: isometric knee extensor and flexor strength. Secondary outcomes: 1-RM, functional capacity, physical activity, and symptom burden.

Main Results:

• Both LL-BFRT and HL-ST groups showed clinically relevant improvements in isometric leg strength, with no significant between-group differences.
• The 1-minute sit-to-stand test performance and daily physical activity levels improved significantly only in the LL-BFRT group.
• LL-BFRT resulted in lower perceived dyspnea and increased leg fatigue during the initial 12 training sessions compared to HL-ST.

Conclusions:

• LL-BFRT is not superior to HL-ST for improving leg strength in COPD patients within pulmonary rehabilitation.
• LL-BFRT achieves comparable strength gains to HL-ST.
• LL-BFRT may offer benefits by reducing perceived dyspnea during the early stages of rehabilitation.