title: Relationship between physical activity, physical performance, and iron status in adult women.
abstract: Iron deficiency affects approximately 16% of US females 18-45 years old. Iron is a key component of heme-containing proteins, which are essential for oxygen transport throughout the body. With low iron levels, performance and intense physical activity may be compromised. Thus, the purpose of this study was to examine the relationship between iron status, physical performance, and physical activity in 18- to 45-year-old females. Participants (N = 109) were screened for iron status using a venous blood sample, had their height and mass measured, and self-reported their physical activity level. The screening was used to match iron-depleted nonanemic females (hemoglobin, Hgb > 120 g·L(-1); serum ferritin, sFer < 20 µg·L(-1)) to females with normal iron levels. After participant matching, they had their body composition measured, performed three cycle ergometer tests (maximal, endurance, and efficiency), and wore an ActiGraph GT1M accelerometer for five consecutive days, except when sleeping or during water activities. The final sample consisted of 25 iron-depleted participants and 24 with normal iron levels. Key findings were as follows: (i) after controlling for fat-free mass and vigorous physical activity, iron-depleted females had a significantly lower [Formula: see text]O(2) at ventilatory threshold compared with those with normal iron levels (P < 0.05); and (ii) after controlling for age, iron-depleted females spent significantly more time in sedentary behaviors and significantly less time in light physical activity than those with normal iron levels (P < 0.05). The increased sedentary time in iron-depleted females may contribute to excess mass gain over time; however, further investigation is needed to confirm these results.
authors.affiliation: Cornell University, Division of Nutritional Sciences, Ithaca, NY 14853, USA. scott.crouter@umb.edu
authors.forename: Scott E
authors.initials: SE
authors.lastname: Crouter
authors.forename: Diane M
authors.initials: DM
authors.lastname: DellaValle
authors.forename: Jere D
authors.initials: JD
authors.lastname: Haas
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D054874:Athletic Performance / Q000502:physiology*; D001799:Blood Sedimentation; D015444:Exercise / Q000502:physiology*; D005260:Female; D005293:Ferritins / Q000097:blood / Q000172:deficiency; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism*; D000090463:Iron Deficiencies; D008875:Middle Aged; D008954:Models, Biological; D009043:Motor Activity / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D055815:Young Adult
chemical_list: D006454:Hemoglobins; D005293:Ferritins; D007501:Iron; D010100:Oxygen