THE EFFECT OF STRENUOUS EXERCISE, CALORIE DEFICIENCY AND SLEEP-DEPRIVATION ON WHITE BLOOD-CELLS, PLASMA IMMUNOGLOBULINS AND CYTOKINES

Moderate exercise appears to stimulate the immune system, but there is good evidence that intense exercise can cause immune deficiency. In t he present study the authors examined the effect of continuous physica l exercise (35% of VO2 max), calorie deficiency and sleep deprivation on the immune system of young men participating in a 5-7 days military training course. There was a two-three fold increase of neutrophils f rom day 1, the values remained high and decreased slightly at the end of the course. Monocyte counts also increased with a pattern similar t o that of neutrophils. Eosinophils decreased to 30% of control and lym phocyte numbers decreased by 30-40%. All the major subgroups (CD4 T ce lls, CD8 T cells, B cells. NK cells) were reduced. Neutrophil function , as tested by measuring chemotaxis, was significantly stimulated duri ng the first days of the course, in particular in the group with the l owest calorie intake. The mitogenic response of lymphocytes to PHA and Con A was variable, ranging from stimulation during one course to no effect in another course. Serum levels of immunoglobulins decreased si gnificantly during the course. IgG was reduced by 6-7%, IgA by 10-20% and IgM by 20-35%. The authors found no changes of interleukin 1, 2 an d 4 during the course, but a (12-20%) reduction (P < 0.01) of interleu kin 6, and an increase (P < 0.01) of granulocyte-macrophage colony sti mulating factor. Altogether the results from the ranger course present a mixed-up picture. The non-specific phagocyte-related immunity was e nhanced. On the other hand, the data indicate that even a moderate phy sical activity, around the clock, caused significant suppression of a number of parameters reflecting the status of the specific, lymphocyte -related immunity. It is noteworthy, however, that there was no signif icantly increased infection rate during the course or in the first 4-5 weeks thereafter.