Effects of walking training at different speeds on body composition, muscle contractility, and immunocytes in the elderly: A single-blinded randomized controlled trial

BACKGROUND

This study investigated the changes in body composition, muscle contractility and immunocytes of the elderly using three types of walking.

MATERIAL AND METHODS

Seventy-six participants were randomly assigned to control group (CON), slow walking group (SWG), moderate walking group (MWG), or fast walking group (FWG).

RESULTS

Muscle mass in CON decreased (-2.55 ± 3.63%; P < 0.05), while it increased in FWG (1.92 ± 4.46%; P < 0.05). Fat mass in CON increased, whereas it decreased in MWG and FWG (-18.71 ± 14.22%; P < 0.001). Tc (contraction time) of biceps femoris (BF) decreased in CON, while a decreasing tendency was seen in SWG. Although Tc of BF increased in MWG, it showed a marked increase in FWG (21.19 ± 24.53%; P < 0.05). A similar tendency was observed in the rectus femoris. Leukocytes did not change in CON, but they showed an increasing tendency in MWG and FWG. Neutrophils decreased in CON, whereas the other groups showed an increasing tendency. Lymphocytes (10.25 ± 19.48%; P < 0.01) and helper T cells (14.32 ± 17.99%; P < 0.05) showed an increase in FWG, and NK cell was improved in SWG, but showed a clear increase in MWG (38.45 ± 96.96%; P < 0.05) and FWG (52.69 ± 58.37%; P < 0.05).

CONCLUSIONS

This study concludes that fast walking by the elderly improves the muscle contractility, which can also be expected to improve the function of immunocytes by increased or maintained muscle mass and decreased fat mass after 12 weeks.

Moderate- to fast-walking improves immunocytes through a positive change of muscle contractility in old women: a pilot study

This study aimed to examine whether compared with a program without walking, intervention programs with three types of walking can improve the muscle property and immunocytes in elderly women. Thirty-two subjects were randomly assigned to control group (CON), slow walking group (SWG), moderate walking group (MWG), and fast walking group (FWG). Three types of walking on treadmill were 30 min a day, 5 days/wk for 12 weeks. Muscle contraction time (Tc), maximum displacement (Dm), and immunocytes were tested by tensiomyography and flow cytometry. After the intervention, FWG had an increasing tendency in the muscle mass compared with other three groups. Tc of biceps femoris (BF) decreased in CON and SWG, while Tc of BF in MWG and FWG (30.58%±23.71%) increased. It was similar in the rectus femoris (RF). Although Dm of BF and RF increased in CON and SWG, those decreased in MWG and FWG. Leucocytes of CON and SWG had a decreasing tendency, those of MWG (9.65%±13.01%) and FWG (13.01%± 13.58%) increased. In the neutrophil, only CON decreased, whereas the three groups showed an increasing tendency. Helper T cell was increased only in FWG (19.61%±19.94%), showing significant differences between groups (P=0.009, η ²=0.378). Natural killer cell was improved in SWG and MWG but showed a clear increase in FWG (75.76%±63.57%). It might be confirmed that walking for elderly increases the muscle property of the lower legs as they walk faster, which might be expected to improve the immunocytes function.

Confined mobility in biomembranes modeled by early stage Brownian motion

An equation of motion, derived from the fractal analysis of the Brownian particle trajectory, makes it possible to calculate the time dependence of the mean square displacement for early times, before the Einstein formula becomes valid. The diffusion coefficient increases with the distance travelled which can be restricted by the geometrical conditions. The corresponding diffusion coefficient cannot increase further to achieve a value characteristic for unrestricted environment. Explicit formula is derived for confined diffusivity related to the unrestricted one as dependent on the maximum particle mean square displacement possible normalized by the square of its mean free path. The model describes the lipid and protein diffusion in tubular membranes with different radii, originally fitted by the modified Saffman-Delbrück equation, and the lateral mobility of synthetic model peptides for which the diffusion coefficient is inversely proportional to the radius of the diffusing object and to the thickness of the membrane.