title: Supplemental vitamin C appears to slow racing greyhounds.
abstract: During strenuous exercise, markers of oxidation increase and antioxidant capacity decreases. Antioxidants such as vitamin C may combat this oxidation stress. The benefits of vitamin C to greyhounds undertaking intense sprint exercise has not been investigated. The objective of this experiment was to determine whether a large dose (1 g or 57 mmol) of ascorbic acid influences performance and oxidative stress in greyhounds. Five adult female, trained racing greyhounds were assigned to receive each of three treatments for 4 wk per treatment: 1) no supplemental ascorbate; 2) 1 g oral ascorbate daily, administered after racing; 3) 1 g oral ascorbate daily, administered 1 h before racing. Dogs raced 500 m twice weekly. At the end of each treatment period, blood was collected before and 5 min, 60 min and 24 h after racing. Plasma ascorbate, alpha-tocopherol, thiobarbituric acid-reducing substances (TBARS) and Trolox equivalent antioxidant capacity (TEAC) concentrations were measured and adjusted to compensate for hemoconcentration after racing. TBARS, TEAC and alpha-tocopherol concentrations were unaffected by supplemental vitamin C. Plasma ascorbic acid concentrations 60 min after racing were higher in dogs that received vitamin C before racing than in dogs that either received no vitamin C or received vitamin C after racing. The dogs ran, on average, 0.2 s slower when supplemented with 1 g of vitamin C, equivalent to a lead of 3 m at the finish of a 500-m race. Supplementation with vitamin C, therefore, appeared to slow racing greyhounds.
authors.affiliation: Department of Small Animal Clinical Sciences and the Center for Veterinary Sports Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Marshall
authors.forename: Karen C
authors.initials: KC
authors.lastname: Scott
authors.forename: Richard C
authors.initials: RC
authors.lastname: Hill
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Lewis
authors.forename: Deborah
authors.initials: D
authors.lastname: Sundstrom
authors.forename: Galin L
authors.initials: GL
authors.lastname: Jones
authors.forename: Jean
authors.initials: J
authors.lastname: Harper
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001205:Ascorbic Acid / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D004285:Dogs / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D009043:Motor Activity / Q000187:drug effects*; D018384:Oxidative Stress / Q000187:drug effects; D012420:Running; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013997:Time Factors; D014810:Vitamin E / Q000097:blood
chemical_list: D000975:Antioxidants; D017392:Thiobarbituric Acid Reactive Substances; D014810:Vitamin E; D001205:Ascorbic Acid