title: Effects of an acute high-intensity interval training protocol on plasma viscosity.
abstract: OBJECTIVE
  High-intensity interval training (HIT) is an exercise model that has been seen to cause similar muscle adaptations and improvements in exercise performance to other traditional exercise models. This study aimed to examine the effects of low-volume HIT exercise on plasma viscosity (PV).
  
  
  METHODS
  Ten healthy male subjects (25.80±3.39 years) randomly performed a HIT running protocol (2-min warm up at 8 km/h, 5x2-min bouts at 90% maximal heart rate, separated by 2-min at 8 km/h, finished with another 2-min period at 8 km/h) or an aerobic (AER) running exercise (60'at 55% VO2max). Blood samples were drawn before and after exercise, and after 30-minute recovery. PV, hematocrit (Hct), fibrinogen, total proteins, triglycerides, total-cholesterol and glucose levels were analyzed. Plasma volume loss during exercise was calculated.
  
  
  RESULTS
  PV rose after HIT (P<0.05) while Hct rose after both protocols. Plasma volume loss was higher after HIT (-6.35±3.47%) than after AER (-3.11±2.49%) (P=0.045). Total-proteins (P<0.001), triglycerides (P=0.013), total-cholesterol (P<0.001) and glucose (P=0.001) concentrations increased after HIT. After AER no statistically significant differences were found in plasma constituents concentrations.
  
  
  CONCLUSIONS
  A low-volume HIT session causes a sufficient loss in plasma volume that leads to significantly incremented plasma constituents' concentrations and, therefore, a mild transient rise in PV.
authors.affiliation: Universitary Research Institute "Dr. Viña Giner", Molecular and Mitochondrial Medicine, Catholic University of Valencia "San Vicente Mártir", Valencia, Spain - rafael.alis@ucv.es.
authors.forename: R
authors.initials: R
authors.lastname: Alis
authors.forename: S
authors.initials: S
authors.lastname: Ibañez-Sania
authors.forename: J
authors.initials: J
authors.lastname: Basterra
authors.forename: F
authors.initials: F
authors.lastname: Sanchis-Gomar
authors.forename: M
authors.initials: M
authors.lastname: Romagnoli
mesh_terms: D000328:Adult; D001786:Blood Glucose; D001798:Blood Proteins / Q000032:analysis; D001809:Blood Viscosity / Q000502:physiology*; D002784:Cholesterol / Q000097:blood; D005340:Fibrinogen / Q000032:analysis; D006400:Hematocrit; D006801:Humans; D008297:Male; D005082:Physical Exertion / Q000502:physiology*; D010953:Plasma Volume; D011897:Random Allocation; D012420:Running / Q000502:physiology*; D014280:Triglycerides / Q000097:blood; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D001798:Blood Proteins; D014280:Triglycerides; D005340:Fibrinogen; D002784:Cholesterol