Effects of lunges inserted in walking (eccentric walking) on lower limb muscle strength, physical and cognitive function of regular walkers.

Abstract

Walking is a popular exercise but does not increase lower limb muscle strength and balance. We hypothesized that muscle strength, physical and cognitive function would be improved by inserting lunges in conventional walking. Eleven regular walkers (54-88 years) who had more than 5000 steps in exercise walking a day at least 5days a week participated in this study. They walked as usual for the first 4weeks and included lunges and descending stairs or slope walking (i.e., eccentric walking) for the next 8weeks. The steps of eccentric walking were gradually increased from 100 to 1000 steps per week over 8weeks. The average steps per day were 10,535 ± 3516 in the first 4weeks, and 10,118 ± 3199 in the eccentric walking period without a significant difference. No significant changes in maximal voluntary isometric contraction torque of the knee extensors (MVC), 30-s chair stand (CS), 2-min step, balance assessed by center of pressure movement area with eyes close, sit and reach, a digit symbol substitution test (DSST) for cognitive function were observed in the first 4weeks. However, significant (P< 0.05) improvements were evident in MVC (18.6 ± 15.7%), CS (24.2 ± 17.3%), balance ( - 45.3 ± 34.5%), and DSST (20.8 ± 16.7%) from weeks 4 to 12. Serum complement component 1q concentration decreased (P < 0.05) from weeks 4 to 12, although no changes in serum glucose, triglyceride, and cholesterol concentrations were observed. These results supported the hypothesis, and suggest that eccentric walking provides effects that are not achieved by conventional walking.