The purpose of this study was to determine the effects of an endurance training program on blood lipids and lipoproteins in adolescents. Fifteen males and 10 females, ages 13 to 18 years, underwent pretest evaluations, including physical measurements, nutritional intake, physical working capacity (PWC), and fasting serum lipid and lipoprotein levels. Physical conditioning consisted of a 16-week progressive endurance training (ET) program 40 min·day1 three times per week. Twenty-five males and females matched for age, sex, and race served as controls. Following the conditioning program, the ET group had a significant increase (p < .05) in PWC and a significant decrease (p < .05) in sum of skinfolds and resting heart rate. A significant decrease (p < .05) was also noted for total cholesterol (TC) and the ratio of TC to high density lipoprotein cholesterol (HDL-C) with a significant increase (p < .05) in HDL-C. No differences were found for the control group. The results suggest that 16 weeks of endurance training favorably improves blood lipid profiles in adolescents.
Daniel L. Blessing, Robert E. Keith, Henry N. Williford, Marjean E. Blessing and Jeff A. Barksdale
Sareen S. Gropper, L. Michelle Sorrels and Daniel Blessing
Copper status was assessed in 70 female collegiate athletes aged 18 to 25 years participating in cross country track, tennis, softball, swimming, soccer, basketball, and gymnastics during the 2000–2001 season. A group of 8 college-aged females, 20 to 23 years of age, who were not collegiate athletes, served as controls. Mean copper intakes including supplements did not differ significantly among the controls and athletic teams. Mean copper intakes including supplements as micrograms/day and percent recommended dietary allowance (RDA) were as follows: controls 1071 ± 772 μg (119 ± 86%), cross country track 1468 ± 851 μg (163 ± 95%), tennis 1099 ± 856 μg (122 ± 95%), softball 654 ± 420 μg (73 ± 47%), swimming 1351 ± 1060 μg (150 ± 118%), soccer 695 ± 368 μg (77 ± 41%), and gymnastics 940 ± 863 μg (104 ± 96%). Forty-one percent of athletes and 29% of controls failed to consume two thirds of the RDA for copper. Mean serum copper and ceruloplasmin concentrations were within the normal range and did not differ significantly among the controls (117 ± 22 μg/dl, 445 ± 122 μg/L) and cross country track (98 ± 17 μg/dl, 312 ± 59 μg/L), tennis (140 ± 84 μg/dl, 424 ± 244 μg/L), softball (95 ± 30 μg/dl, 310 ± 77 μg/L), swimming (98 ± 25 μg/dl, 312 ± 40 μg/L), soccer (93 ± 15 μg/dl, 324 ± 54 μg/ L), basketball (85 ± 10 μg/dl, 280 ± 62 μg/L), and gymnastics (96 ± 21 μg/dl, 315 ± 68 μg/L) teams. Copper status of female collegiate athletes appears to be adequate in this cross-sectional assessment.
Henry N. Williford, Michele Scharff Olson, Robert E. Keith, Jeffrey M. Barksdale, Daniel L. Blessing, Nai-Zhen Wang and Pete Preston
This investigation evaluated the iron and nutritional status of 12 highly trained aerobic dance instructors who did not take iron supplements (ANS) and 8 who did (AS). A control group (C) consisted of 10 age matched controls. The aerobic instructors had exercised for approximately 3.8 days/wk, 56 min/session for the past 7 yrs. There were no significant differences among groups for energy intake, carbohydrate, protein, fat, nonheme iron, heme iron, or total iron intake (excluding supplemental iron). But both exercise groups had lower ferritin values than the control group. There was also a significant difference in mean cell volume (MCV), with both exercise groups having greater values than the control group. There were no differences among groups for serum iron, total iron binding capacity, transferrin saturation, hematocrit, or hemoglobin. One in three aerobic dance instructors had serum ferritin values below 12 μg · L−1. Results indicate that women exercise leaders have iron profiles that are similar to other groups of female athletes. The increased MCV values suggest runners' macrocytosis or an exercise induced macrocytosis.