Hyvärinen Matti, Kankaanpää Anna, Rantalainen Timo, Rantanen Taina, Laakkonen Eija K, Karavirta Laura
Gerontology Research Center, Faculty of Sport and Health Sciences, University of Jyväskylä, Jyväskylä, Finland.
Eur Rev Aging Phys Act. 2025 May 1;22(1):6. doi: 10.1186/s11556-025-00372-z.
Body composition and functional capacity are both related to physical activity, but the interplay is complex, as different body tissue types contribute differently on physical activity and functional capacity. To clarify the role of body composition and functional capacity as determinants of physical activity in aging, we investigated the associations of different body tissue types, muscle strength, and walking capacity with physical activity in middle-aged and older adults.
This cross-sectional study involved 1158 women aged 47-55 years, and community-dwelling 289 women and 196 men aged 75, 80, or 85 years. Their physical activity was assessed with accelerometers, muscle mass and muscle-free mass with bioelectrical impedance analysis, walking performance with a six-minute walking test, and muscle strength with maximal isometric knee extension test. The associations of muscle mass, muscle-free mass, walking performance, and muscle strength with physical activity were studied separately for middle-aged women, older women, and older men using linear regression and structural equation models.
Total body mass and absolute muscle-free mass were inversely associated with the level of physical activity in all study groups. Furthermore, walking performance, muscle strength, and muscle mass relative to body weight, but not absolute muscle mass, were directly associated with the level of physical activity. The associations between the measures of body composition and physical activity were fully explained by the differences in functional capacity, as defined by both walking performance and muscle strength, in structural equation models. Functional capacity was strongly associated with higher levels of physical activity regardless of body composition, especially among older people: β = 0.70, SE = 0.10 for older women, β = 0.92, SE = 0.27 for older men, and β = 0.41, SE = 0.10 for middle-aged women.
Reduced functional capacity may be a key factor limiting physical activity, with its impact becoming more pronounced as functional capacity declines with age. Based on these findings, maintaining and improving functional capacity is essential for promoting an active lifestyle in older adults.
身体成分与功能能力均与体力活动相关，但它们之间的相互作用较为复杂，因为不同类型的身体组织对体力活动和功能能力的贡献各不相同。为了阐明身体成分和功能能力作为衰老过程中体力活动决定因素的作用，我们研究了不同身体组织类型、肌肉力量和步行能力与中老年人群体力活动之间的关联。
这项横断面研究纳入了1158名年龄在47 - 55岁的女性，以及289名年龄在75、80或85岁的社区居住女性和196名男性。通过加速度计评估他们的体力活动，采用生物电阻抗分析评估肌肉质量和去脂体重，通过6分钟步行试验评估步行能力，采用最大等长膝关节伸展试验评估肌肉力量。使用线性回归和结构方程模型，分别对中年女性、老年女性和老年男性的肌肉质量、去脂体重、步行能力和肌肉力量与体力活动之间的关联进行了研究。
在所有研究组中，总体重和绝对去脂体重与体力活动水平呈负相关。此外，步行能力、肌肉力量以及相对于体重的肌肉质量（而非绝对肌肉质量）与体力活动水平呈正相关。在结构方程模型中，由步行能力和肌肉力量所定义的功能能力差异，充分解释了身体成分测量指标与体力活动之间的关联。无论身体成分如何，功能能力与较高水平的体力活动密切相关，尤其是在老年人中：老年女性β = 0.70，标准误 = 0.10；老年男性β = 0.92，标准误 = 0.27；中年女性β = 0.41，标准误 = 0.10。
功能能力下降可能是限制体力活动的关键因素，随着年龄增长功能能力下降，其影响会愈发明显。基于这些发现，维持和改善功能能力对于促进老年人积极的生活方式至关重要。
