title: The effects of resistance exercise and post-exercise meal timing on the iron status in iron-deficient rats.
abstract: Resistance exercise increases heme synthesis in the bone marrow and the hemoglobin in iron-deficient rats. Post-exercise early nutrient provision facilitates skeletal muscle protein synthesis compared to late provision. However, the effects of post-exercise nutrition timing on hemoglobin synthesis are unclear. The current study investigated the effect of post-exercise meal timing on the activity of the key enzyme involved in hemoglobin synthesis, δ-aminolevulinic acid dehydratase (ALAD), in the bone marrow and examined the hemoglobin concentration in iron-deficient rats. Male 4-week-old Sprague-Dawley rats were fed an iron-deficient diet containing 12 mg iron/kg and performed climbing exercise (5 min × 6 sets/day, 3 days/week) for 3 weeks. The rats were divided into a group fed a post-exercise meal early after exercise (E) or a group fed the meal 4 h after exercise (L). A single bout of exercise performed after the 3-week training period increased the bone marrow ALAD activity, plasma iron concentration, and transferrin saturation. Although the plasma iron concentration and transferrin saturation were lower in the E group than the L group after a single bout of exercise, the basal hematocrit, hemoglobin, and TIBC after 3 weeks did not differ between the groups. Therefore, resistance exercise increases the bone marrow ALAD activity, while the post-exercise meal timing has no effect on the hemoglobin concentration in iron-deficient rats.
authors: Exercise Nutrition Laboratory, Graduate School of Sport Sciences, Osaka University of Health and Sport Sciences, Osaka, Japan. 210d04@ouhs.ac.jp
authors: Takako
authors: T
authors: Fujii
authors: Tatsuhiro
authors: T
authors: Matsuo
authors: Koji
authors: K
authors: Okamura
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000201:enzymology / Q000378:metabolism; D004032:Diet; D006400:Hematocrit; D006454:Hemoglobins / Q000096:biosynthesis*; D007501:Iron / Q000097:blood*; D000090463:Iron Deficiencies; D019266:Iron, Dietary / Q000008:administration & dosage; D008297:Male; D010805:Physical Conditioning, Animal / Q000502:physiology*; D000623:Porphobilinogen Synthase / Q000097:blood / Q000378:metabolism; D019518:Postprandial Period; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014168:Transferrin / Q000378:metabolism
chemical_list: D006454:Hemoglobins; D019266:Iron, Dietary; D014168:Transferrin; D007501:Iron; D000623:Porphobilinogen Synthase