title: Effects of conditioning and maximal incremental exercise on oxygen consumption in sheep.
abstract: To assess the suitability of sheep for exercise studies, the effect of incremental exercise and conditioning on oxygen consumption (VO2) was studied. Six sheep were adapted to a treadmill and subsequently trained 8 weeks. The sheep were then studied, in random order, using 3 incremental exercise protocols (EX-1, EX-2, and EX-3). The protocols were chosen to approximate high (EX-1), moderate (EX-2), and low (EX-3) intensity exercise by varying treadmill speed and incline. The sheep were then conditioned for an additional 12 weeks and retested on the EX-2 protocol. During exercise, VO2, gas exchange ratio (R), and rectal temperatures (Tb) were recorded. All 3 protocols resulted in significant increases in VO2, R, and Tb (P less than 0.05). Maximum VO2 for EX-1, 49.9 +/- 5.0 ml/min/kg of body weight, was significantly greater than maximum VO2 for EX-2 and EX-3, 37.8 +/- 6.5 and 42.3 +/- 6.0 ml/min/kg, respectively (P less than 0.05), whereas maximum R and maximum Tb were similar. After the additional 12-week conditioning, time on the treadmill increased 40% from 9.58 +/- 0.87 to 13.4 +/- 0.44 minutes, and maximum VO2 increased 27% to 48.1 +/- 9.1 ml/min/kg. These data indicated that maximum VO2 varied with intensity of the exercise, 12 weeks of maximal exercise conditioning was sufficient to produce a measurable training effect (ie, increase endurance and maximum oxygen consumption) and sheep are suitable for maximal exercise studies where VO2 measurements are desired.
authors.affiliation: Department of Respiratory Research, Walter Reed Army Institute of Research, Washington, DC 20307-5100.
authors.forename: T G
authors.initials: TG
authors.lastname: Mundie
authors.forename: A J
authors.initials: AJ
authors.lastname: Januszkiewicz
authors.forename: D B
authors.initials: DB
authors.lastname: Rayburn
authors.forename: D G
authors.initials: DG
authors.lastname: Martin
authors.forename: G R
authors.initials: GR
authors.lastname: Ripple
mesh_terms: D000818:Animals; D005260:Female; D010101:Oxygen Consumption; D010805:Physical Conditioning, Animal; D012756:Sheep / Q000378:metabolism*