Effect of 6-day intense Kendo training on lymphocyte counts and its expression of CD95

This study examines the effects of 6-day intensive training on lymphocyte counts and their expression of CD95. Eight healthy Kendo athletes underwent 6-day Kendo training of about 310 min each day. Blood samples were collected at 2 weeks before (PRE), the first day (Day 1), third day (Day 3), fifth day (Day 5), and 1 week after the training period (POST) to determine lymphocyte counts and CD95 expression on CD95 lymphocytes (CD4(+), CD8(+)) using flow cytometry. The total lymphocyte counts were significantly lower at Day 3 than at PRE. The CD8(+) cell counts were significantly lower at Day 3 than at PRE. The percentage of CD95(+) lymphocytes was significantly higher at Day 1 and Day 3 than at PRE. The percentage of CD8(+)CD95(+) cells did not change significantly. The total lymphocyte counts decreased and a concomitant increase of CD95(+) lymphocyte was observed, whereas the decrease in CD8(+) cell counts was not associated with the increase in CD8(+)CD95(+) cells. Therefore, short-term high-intensity exercise induced a decrease in the T lymphocyte counts without increasing in CD95(+) expression.