The purpose of this study was to investigate the effect of training by walking on plasma reduced glutathione (GSH) and glutathione reductase (GR) levels as indicators of anti-oxidative capacity in healthy middle-aged and elderly females. The effect of training by walking on plasma lipoprotein variables as indicators of cardiovascular fitness was also determined. Seventeen subjects had been habitual walkers for more than one year and measured their steps every day during three weeks before the blood sampling.
　The average daily steps (mean ± SD) of the subjects was 11019.1 ± 3658.9 (steps/day). Physical activity levels tended to increase GSH and GR levels in the plasma. Although there was no significant relationship between the plasma GSH concentrations and the average daily steps, GR activity significantly (r=0.610, p<0.01) correlated with the average daily steps. The average daily steps did not influence plasma lipid peroxides, total cholesterol, HDL-cholesterol, and trigliceride concentrations. Furthermore, we made a comparison about the above blood parameters between the group which average daily steps were lower than 12000 steps/day (L) and the group which average daily steps were more than 12000 steps/day (H). There was no significant difference in any blood parameters between the L and H group.
　These results suggest that training by walking can increase anti-oxidative capacity such as glutathione system, especially in GR activity in the plasma, but can not influence plasma lipoprotein variables.

DESCENTE SPORTS SCIENCE Vol.21/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE