Effectiveness of low-load resistance training with blood flow restriction vs. conventional high-intensity resistance training in older people diagnosed with sarcopenia: a randomized controlled trial.

Low-load resistance training with blood flow restriction (LRT-BFR) has shown potential to improve muscle strength and mass in different populations; however, there remains limited evidence in sarcopenic people diagnosed with sarcopenia criteria. This study systematically compared the effectiveness of LRT-BFR and conventional high-intensity resistance training (CRT) on clinical muscle outcomes (muscle mass, strength and performance), cardiovascular disease (CVD) risk factors and sarcopenia-related biomarkers of older people with sarcopenia. Twenty-one older individuals (aged 65 years and older) diagnosed with sarcopenia were randomly assigned to the LRT-BFR (20%-30% one-repetition maximum (1RM), n = 10) or CRT (60%-70% 1RM, n = 11) group. Both groups underwent a supervised exercise program three times a week for 12 weeks. The primary outcome was knee extensor strength (KES), and the secondary outcomes included body composition (body mass, body mass index and body fat percentage), muscle mass [appendicular skeletal muscle mass index (ASMI)], handgrip strength, physical performance [short physical performance battery (SPPB) and 6-m walk], CVD risk factors [hemodynamic parameters (systolic and diastolic blood pressure and heart rate (SBP, DBP and HR)) and lipid parameters (total cholesterol, triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein)], sarcopenia-related blood biomarkers [inflammatory biomarkers, hormones (growth hormone (GH) and insulin-like growth factor 1) and growth factors (myostatin and follistatin)] and quality of life [Short Form 36 Health Survey (SF-36)]. Both interventions remarkably improved the body composition, KES, 6-m walk, SBP, HDL, TG, GH, FST and SF-36 scores. CRT significantly improved the ASMI (p < 0.05) and SPPB (p < 0.05). A significant improvement in HR was observed only after LRT-BFR. No significant between-group differences were found before and after the interventions. This study suggested that LRT-BFR and CRT are beneficial to the clinical muscle outcomes, CVD risk factors and certain sarcopenia-related biomarkers of older people with sarcopenia. By comparison, CRT seems more effective in improving muscle mass, while LRT-BFR may be more beneficial for improving cardiovascular health in this population. Therefore, LRT-BFR is a potential alternative to CRT for aging sarcopenia.