title: No influence of ischemic preconditioning on running economy.
abstract: OBJECTIVE
  Many of the potential performance-enhancing properties of ischemic preconditioning suggest that the oxygen cost for a given endurance exercise workload will be reduced, thereby improving the economy of locomotion. The aim of this study was to identify whether ischemic preconditioning improves exercise economy in recreational runners.
  
  
  METHODS
  A randomized sham-controlled crossover study was employed in which 18 adults (age 27 ± 7 years; BMI 24.6 ± 3 kg/m2) completed two, incremental submaximal (65-85% VO2max) treadmill running protocols (3 × 5 min stages from 7.2-14.5 km/h) coupled with indirect calorimetry to assess running economy following ischemic preconditioning (3 × 5 min bilateral upper thigh ischemia) and sham control. Running economy was expressed as mlO2/kg/km and as the energy in kilocalories required to cover 1 km of horizontal distance (kcal/kg/km).
  
  
  RESULTS
  Ischemic preconditioning did not influence steady-state heart rate, oxygen consumption, minute ventilation, respiratory exchange ratio, energy expenditure, and blood lactate. Likewise, running economy was similar (P = 0.647) between the sham (from 201.6 ± 17.7 to 204.0 ± 16.1 mlO2/kg/km) and ischemic preconditioning trials (from 202.8 ± 16.2 to 203.1 ± 15.6 mlO2/kg/km). There was no influence (P = 0.21) of ischemic preconditioning on running economy expressed as the caloric unit cost (from 0.96 ± 0.12 to 1.01 ± 0.11 kcal/kg/km) compared with sham (from 1.00 ± 0.10 to 1.00 ± 0.08 kcal/kg/km).
  
  
  CONCLUSIONS
  The properties of ischemic preconditioning thought to affect exercise performance at vigorous to severe exercise intensities, which generate more extensive physiological challenge, are ineffective at submaximal workloads and, therefore, do not change running economy.
authors.affiliation: Vascular Protection Research Laboratory, Box 2203, Intramural 116, Department of Health and Nutritional Sciences, South Dakota State University, Brookings, SD, 57007, USA.
authors.forename: Gungeet
authors.initials: G
authors.lastname: Kaur
authors.affiliation: Vascular Protection Research Laboratory, Box 2203, Intramural 116, Department of Health and Nutritional Sciences, South Dakota State University, Brookings, SD, 57007, USA.
authors.forename: Megan
authors.initials: M
authors.lastname: Binger
authors.affiliation: Vascular Protection Research Laboratory, Box 2203, Intramural 116, Department of Health and Nutritional Sciences, South Dakota State University, Brookings, SD, 57007, USA.
authors.forename: Claire
authors.initials: C
authors.lastname: Evans
authors.affiliation: Vascular Protection Research Laboratory, Box 2203, Intramural 116, Department of Health and Nutritional Sciences, South Dakota State University, Brookings, SD, 57007, USA.
authors.forename: Tiffany
authors.initials: T
authors.lastname: Trachte
authors.affiliation: Vascular Protection Research Laboratory, Box 2203, Intramural 116, Department of Health and Nutritional Sciences, South Dakota State University, Brookings, SD, 57007, USA. gary.vanguilder@sdstate.edu.
authors.forename: Gary P
authors.initials: GP
authors.lastname: Van Guilder
mesh_terms: D000293:Adolescent; D000328:Adult; D054874:Athletic Performance; D018592:Cross-Over Studies; D004734:Energy Metabolism / Q000502:physiology; D005080:Exercise Test / Q000379:methods; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007511:Ischemia / Q000503:physiopathology*; D019194:Ischemic Preconditioning; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology; D012420:Running / Q000502:physiology*; D055815:Young Adult
keywords: Endurance performance; Exercise economy; Ischemia; Oxygen uptake; Reperfusion