Serum ferritin and serum iron changes after cross-country and roller ski endurance races.

We have studied the variations induced in iron status parameters by four endurance races of different lengths. A comprehensive group of 48 healthy, non-iron deficient, endurance athletes were evaluated before and after four different cross-country and roller ski races: I = Skirollonga, roller ski race for individuals (n = 10), mean duration (MD) = I h 48 min; II = Marcialonga, cross-country ski race for individuals (n = 9) MD = 3 h 10 min; III = 12-h of Caldonazzo (Trento-Italy) roller ski relay race (n = 13) MD = 12 h; IV = 24-h of Pinzolo (Trento-Italy) cross-country ski relay race (n = 16) MD = 24 h. In the relays the MD includes both exercise and recovery times. Blood samples were taken before and after every race for the determination of the following haematological parameters: red blood count, haemoglobin, and packed cell volume, serum iron concentration [SI], serum ferritin concentration [FERR] and total iron binding capacity (TIBC). The results showed a constant significant increase of [FERR] after the races (+ 44.9% in I, + 50.5% in II, + 51.2% in III and + 36.5% in IV, P<0.01) while [SI] increased only in the first two races (+ 28.2% in I and + 19.7% in II, P < 0.01) and showed a remarkable decrease in the longer races (-46.1% in III and -39% in IV, P< 0.01). The TIBC increased in all the races (except II) to the same extent (range 10%-12%). These data suggest that prolonged exercise may accelerate iron metabolism and produce large variations in iron status parameters. The increase in [FERR], observed in the four races, may be attributed to a new synthesis in the reticulo-endothelial cells as well as to a release from the iron stores. © 1990 Springer-Verlag.