White cell system changes associated with a training period of 18-20 months: a transverse and a longitudinal approach.

In the present study 60 males and 18 females were monitored during an 18- to 20-month training period, during which the training distance was gradually increased. The training period was divided into three periods of 6, 5, and 7 months, respectively. The first, second, and third periods were concluded with a 15-, 25-, and 42-km road race, respectively. The competitive distance always exceeded the maximal distance covered in any previous training session. The effect of training was investigated for the number of leukocytes, number of the subpopulations, and the percentage of white cells with a higher peroxidase activity (HPX cells). The measuring points were the start of the study (used as a reference value) and 1 week before and 1 week after three contests (15, 25, and 42 km). The results of all measuring points were compared transversely and longitudinally. Transversely the leukocytes hardly changed in the course of the study both in males and females, except a decrease of HPX cells. Longitudinally it appeared that Nvar and CVp90 of the numbers of leukocytes could not be calculated in males or in females. These findings suggest that a homogeneous population of leukocytes developed with respect to number and age.