title: High intensity interval running enhances measures of physical fitness but not metabolic measures of cardiovascular disease risk in healthy adolescents.
abstract: BACKGROUND
  With accumulating evidence suggesting that CVD has its origins in childhood, the purpose of this study was to examine whether a high intensity training (HIT) intervention could enhance the CVD risk profile of secondary school aged adolescents in a time efficient manner.
  
  
  METHODS
  Participants in the study were adolescent school children (64 boys, 25 girls, 16.7 ± 0.6 years). The intervention group (30 boys, 12 girls) performed three weekly exercise sessions over 7 weeks with each session consisting of either four to six repeats of maximal sprint running within a 20 m area with 30 s recovery. The control group were instructed to continue their normal behaviour. All participants had indices of obesity, blood pressure and nine biochemical risk markers for cardiovascular disease recorded as well as four physical performance measures at baseline and post-intervention. Feedback was provided through informal discussion throughout the intervention period as well as post-intervention focus groups. Statistical differences between and within groups were determined by use of paired samples t-tests and ANCOVA.
  
  
  RESULTS
  Significant enhancements (P ≤ 0.05) in vertical jump performance, 10 m sprint speed and cardiorespiratory fitness was evident in the intervention group whereas a significant decrease in both agility and vertical jump performance was evident in the control group. Participants in the intervention group also experienced a significant decrease in systolic blood pressure post-intervention. Limited changes occurred with respect to the biochemical markers although both groups did experience a significant increase in LDL post-intervention whilst the control group experienced a significant decrease in total cholesterol. No apparent differences were evident between groups post intervention for any of the biochemical markers. Feedback indicated that participants endorsed the use of the intervention as an effective means of exercise.
  
  
  CONCLUSIONS
  Our results demonstrate that high intensity exercise interventions may be used in the school setting for adolescents as a means of improving measures of physical fitness. Further investigations involving a larger cohort of participants, taken from different schools, is recommended.
  
  
  BACKGROUND
  NCT01027156.
authors.affiliation: Institute for Clinical Exercise and Health Science, School of Science, University of the West of Scotland, Hamilton, Scotland ML3 0JB, UK. duncan.buchan@uws.ac.uk
authors.forename: Duncan S
authors.initials: DS
authors.lastname: Buchan
authors.forename: Stewart
authors.initials: S
authors.lastname: Ollis
authors.forename: John D
authors.initials: JD
authors.lastname: Young
authors.forename: Stephen-Mark
authors.initials: SM
authors.lastname: Cooper
authors.forename: Julian P H
authors.initials: JP
authors.lastname: Shield
authors.forename: Julien S
authors.initials: JS
authors.lastname: Baker
mesh_terms: D000293:Adolescent; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D002784:Cholesterol / Q000378:metabolism; D008078:Cholesterol, LDL / Q000378:metabolism; D005260:Female; D017144:Focus Groups; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D010809:Physical Fitness / Q000502:physiology*; D012307:Risk Factors; D012420:Running / Q000502:physiology*; D012572:School Health Services
chemical_list: D008078:Cholesterol, LDL; D002784:Cholesterol