Effects of 8-week kettlebell training on body composition, muscle strength, pulmonary function, and chronic low-grade inflammation in elderly women with sarcopenia

Objectives: To examine the effect of kettlebell training on body composition, muscle strength, pulmonary function, and chronic low-grade inflammatory markers among elderly people with sarcopenia. Design: Randomized controlled trial. Setting: Community center and research center. Participants: A total of 33 elderly women with sarcopenia (aged 65-75 years) were recruited. Intervention: The participants were randomly assigned to a kettlebell training (KT) group or a control (CON) group. The KT group received an 8-week training intervention involving 60-min sessions twice a week, whereas the CON group members continued their daily lifestyles without participating in any exercise training. Four weeks of detraining were organized to observe the retention effect of the training program on the KT group. Measurements: The participants' body composition, muscle strength, pulmonary function, and chronic low-grade inflammatory markers were measured and analyzed before training (at Week 0, W0), after 8 weeks of training (at Week 8, W8), and after 4 weeks of detraining (at Week 12, W12). Results: In the KT group, appendicular skeletal muscle mass (ASM) and the sarcopenia index measured at W8 and W12 were significantly higher than those at W0(p=.004; p=.005). At W8 and W12, the sarcopenia index was significantly higher in the KT group than the CON group(p=.020; p=.019). In the CON group, the skeletal muscle mass levels measured at W8 and W12 were significantly lower than that at W0(p=.029; p=.005), and the ASM and the sarcopenia index measured at W8 were significantly lower than those at W0(p=.037; p=.036). Additionally, the measured left handgrip strength(p=.006), back strength(p=.011; p=.018), and peak expiratory flow (PEF) (p=.008; p=.006) were significantly higher in the KT group than the CON group at W8 and W12. At W8, the measured right handgrip strength was significantly higher in the KT group than the CON group(p=. 043). In the KT group, the back strength and PEF levels measured at W8 and W12 were significantly higher than those at W0(p=. 000; p=. 004), and the left and right handgrip strength levels at W8 were significantly higher than those at W0(p=. 004; p=. 013). By contrast, in the CON group, the left(p=. 004; p=. 006) and right(p=. 002; p=. 004) handgrip strength levels and PEF(p=. 018; p=. 012) measured at W8 and W12 were significantly lower than those at W0. Moreover, compared with the high-sensitivity C-reactive protein (hs-CRP) levels measured at W0, those measured at W8 and W12 were significantly lower in the KT group(p=. 006; p=. 013) but significantly higher in the CON group(p=. 005; p=. 009). There was no significant difference in hs-CRP, IL-6, TNF-alpha between the KT and CON group. Conclusion: For elderly people with sarcopenia, participating in kettlebell training significantly increases the sarcopenia index, grip strength, back strength, and PEF. In addition, the retention effect of the training program continued after 4 weeks of detraining.