Erythrocyte Changes during Training in High School Women Cross-Country Runners

Selected indices of iron and fitness status of women participating in an exercise clinic

“…Iron stores are marginal or absent in many women due to low iron intakes and high iron needs to compensate for menstrual losses (Bowering et al, 1976;Cook and Finch, 1979;. If physical training increases iron needs, especially to compensate for increased erythropoiesîs at the beginning of conditioning, as has been suggested (Buskirk and Haymes, 1972;De WTjn et al, 1971;Ehn et al, 1980;Puhl and Runyan, 1980a;Puhl et al, 1981;Ruckman and Sherman, 1981;Strauzenberg et al, 1979), then an exercise program could increase the incidence of iron deficiency among those female participants who have inadequate iron reserves. Inasmuch as îron balance is precarious for many women, they have received surprisingly scant attention as subjects regarding training-induced anemia.…”

“…Results are often at variance, possibly due to sex, training intensity, or blood sampling interval differences between studies. Red cell indices (MCH, MCHC, and MCV) temporarily decreased or remained unchanged in male trainees (Dressendorfer et al, 1981;Radomski et al, 1980), but MCV increased in females (Puhl and Runyan, 1980a;Puhl et al, 1981). Serum iron levels rose with training in men (Dressendorfer et al, 1981), but fell in women (Frederickson, 1980).…”

“…The condition has developed among men during periods of a sudden increase in physical activity, including events such as a 312 mile, 20-day road race (Dressendorfer et al, 1981), a k-or 5-day, 21 hours/day army combat course (Lindemann et al, 1978), a 4 hour/day Marine Corps training program (Rasch et al, I969), a 6-day, 35 km/day march at 35% maximal VO^ (Radomski et al, 1980), rugby training for 4 to 4.5 hours/day, and bicycle ergometer training for 2 hours/day at a relative metabolic rate (RMR, the ratio of energy requirement of the work to basal metabolism) of 7 (Yoshimura et al, 1980). A sports anemia effect in high school and collegiate women has been demonstrated during training periods for basketball (Yoshimura et al, 1980) and running (Frederickson, 1980;Puhl and Runyan, 1980a;Puhl et al, 1981). The phenomenon did not occur in a group of already highly-trained collegiate women runners who increased their weekly training distance from 40 or 50 up to 50 or 60 miles (Puhl and Runyan, 1980b), nor in two groups of male runners, one of which was physically active but untrained as runners and the second of which was composed of recreational distance runners, who ran 4 miles at 75% maximal VO^ every other day (Hanson et al, 1978).…”

“…A limited number of studies involving women subjects has been reported where blood sampling intervals were frequent during the training period (Frederickson, 1980;Puhl and Runyan, 1980a, b;Puhl et al, 1981;Horiguchi et al, 1975, as cited by Yoshimura et al, 1980).…”

“…Pseudoanemic hematological changes may occur during the initial stages of vigorous physical training, possibly because of an increased rate of red cell destruction or increased plasma volume, or both (Puhl and Runyan, 1980a;Puhl et al, 1981;Radomski et al, 1980;Yoshimura et al, 1980). This "sports anemia" effect is characterized by values for hgb and RBC concentrations and hct that, although decreased, stay within normal ranges and return to pretraining levels after 2 or 3 weeks (Yoshimura et al, 1980).…”