Document Type

Thesis - University Access Only

Award Date

2011

Degree Name

Master of Science (MS)

Department / School

Health and Nutritional Sciences

First Advisor

Kendra Kattelmann

Abstract

Purpose: The purpose of this study was to examine if supplementation with lean beef would result in maintenance of iron status, improvement in body composition and increase in performance compared to a multivitamin supplement alone. It was hypothesized that supplementation with increased amounts of lean beef would maintain the iron status, and improve the body composition and performance of collegiate distance runners over an 8-week period. Methods: Twenty-eight (14 male and 14 female) NCAA Division I cross country runners from South Dakota State University, who were 18-24 years of age, were stratified according to their baseline iron status, current use of iron supplements, and gender, and randomized into the control (n = 14) or intervention (n = 14) group. All participants continued to exercise per their regular training regimen throughout the 8-week intervention period. All subjects were to maintain their typical diet and consume the daily multivitamin, while the intervention group was to consume 9 ounces of the lean beef supplement each week via 1 ounce servings. Dietary intake (total iron, heme-iron, protein, and zinc), body composition, VO2 max until volitional exhaustion, and blood markers of iron status (hemoglobin, hematocrit, serum iron, serum ferritin, and total iron binding capacity (TIBC)) were measured at baseline and post-intervention. Results: The intervention group had greater intakes of total iron and hemeiron. There were no differences between groups in amino acid, protein, and calorie intake. There was a near significant group x time effect in heme-iron intake (p=.057, control: baseline 1.9 ± 0.3 to post 1.4 ± 0.4; intervention: 2.1 ± 0.3 to 3.0 ± 0.3). There was a significant increase in body fat seen in both groups (p=.034, control: baseline 11.8 ± 0.6 to post 13.9 ± 0.8; intervention: 12.8 ± 0.5 to 13.6 ± 0.7). The percentage oflean mass in both groups deceased significantly over time (p=.034, control: baseline 88.2 ± 0.6 to post 86.1 ± 0.8; intervention: 87.2 ±0.5 to 86.4 ± 0.7). There was a significant increase in V 02 max from baseline to post in both groups. There was a significant difference between groups as a result of the intervention in hematocrit (p=.051, control: baseline 42.5 ± 1. 1 to post 41.1 ± 1.2; intervention: 40.0 ± 1.0 to 43 .1 ± 1.0). Conclusion: In conclusion, increasing bioavailable iron from red meat may have effects on body composition and maintenance of blood iron markers; however, its direct impact on performance among endurance athletes is unclear.

Library of Congress Subject Headings

College athletes -- Nutrition
Long-distance runners -- Nutrition
Iron in the body
Beef

Publisher

South Dakota State University

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Rights Statement

In Copyright