The purpose of this study was to investigate whether there were any seasonal differences both in the number of steps taken and in % body fat among middle-aged males in the northern country. We found that there was a seasonal difference of 539 steps between the number of steps taken in the summer season and those taken in the winter, but the difference was not statistically significant. Also, we found a significant difference of 2.3% in the % body fat among the subjects between summer and autumn. Our findings may indicate that doing exercise from autumn through winter is especially important for northerners to prevent obesity and lifestyle-related diseases.