Biomaterial Database

Altered metabolic response of iron-depleted nonanemic women during a 15-km time trial. 1998

Y I Zhu, and J D Haas

Division of Nutritional Sciences, Cornell University, Ithaca, New York 14853, USA. yizl@columbia.edu

In this double-blinded study, 37 women with iron depletion without anemia (age 19-36 yr) were randomly assigned to receive either an iron supplement (135 mg/day) or a placebo. Endurance capacity was assessed during a 15-km simulated time trial (TT) on a cycle ergometer before and after the 8-wk treatment. After the treatment, although the iron-supplemented group did not have shorter time to finish the TT (time), it had 2.0 kJ/min lower energy expenditure and 5.1% lower fractional utilization of peak oxygen consumption during the TT compared with the placebo group, after controlling for work rate (P < 0.05). Time, fractional utilization of peak oxygen consumption, and plasma lactate concentration at the 5th km of the TT were all negatively associated with hemoglobin levels, after controlling for work rate (P < 0.05). In conclusion, repletion of iron stores to women with iron depletion without anemia increased their energetic efficiency, and oxygen transport capacity of the blood was found to be an important determinant of endurance capacity and energy metabolism in nonanemic women.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D010101	Oxygen Consumption	The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)	Consumption, Oxygen,Consumptions, Oxygen,Oxygen Consumptions
D010807	Physical Endurance	The time span between the beginning of physical activity by an individual and the termination because of exhaustion.	Endurance, Physical,Physical Stamina,Stamina, Physical
D012044	Regression Analysis	Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.	Regression Diagnostics,Statistical Regression,Analysis, Regression,Analyses, Regression,Diagnostics, Regression,Regression Analyses,Regression, Statistical,Regressions, Statistical,Statistical Regressions
D012123	Pulmonary Ventilation	The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.	Respiratory Airflow,Ventilation Tests,Ventilation, Pulmonary,Expiratory Airflow,Airflow, Expiratory,Airflow, Respiratory,Test, Ventilation,Tests, Ventilation,Ventilation Test
D001786	Blood Glucose	Glucose in blood.	Blood Sugar,Glucose, Blood,Sugar, Blood
D001835	Body Weight	The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.	Body Weights,Weight, Body,Weights, Body
D004311	Double-Blind Method	A method of studying a drug or procedure in which both the subjects and investigators are kept unaware of who is actually getting which specific treatment.	Double-Masked Study,Double-Blind Study,Double-Masked Method,Double Blind Method,Double Blind Study,Double Masked Method,Double Masked Study,Double-Blind Methods,Double-Blind Studies,Double-Masked Methods,Double-Masked Studies,Method, Double-Blind,Method, Double-Masked,Methods, Double-Blind,Methods, Double-Masked,Studies, Double-Blind,Studies, Double-Masked,Study, Double-Blind,Study, Double-Masked
D004734	Energy Metabolism	The chemical reactions involved in the production and utilization of various forms of energy in cells.	Bioenergetics,Energy Expenditure,Bioenergetic,Energy Expenditures,Energy Metabolisms,Expenditure, Energy,Expenditures, Energy,Metabolism, Energy,Metabolisms, Energy
D005082	Physical Exertion	Expenditure of energy during PHYSICAL ACTIVITY. Intensity of exertion may be measured by rate of OXYGEN CONSUMPTION; HEAT produced, or HEART RATE. Perceived exertion, a psychological measure of exertion, is included.	Physical Effort,Effort, Physical,Efforts, Physical,Exertion, Physical,Exertions, Physical,Physical Efforts,Physical Exertions