Effect of training on red blood cell parameters and plasma ferritin: 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 erythrocyte count, hematocrit (Ht), hemoglobin (Hb), mean cell volume (MCV), mean cell hemoglobin (MCH), mean cellular hemoglobin content (MCHC), the red cell distribution width (RDW), and ferritin content. The measuring points were the start of the study (used as a reference value) and 1 week before and 1 week after the three contests (15, 25, and 42 km). The results of all measuring points were compared transversely and longitudinally. We found a significant decrease of plasma ferritin content in the first period of the study which further remained constant. Also, other red cell parameters were decreased but remained within the normal range. During the whole training period larger intraindividual variations for most of the red cell parameters were observed compared with non-endurance-trained people.