title: Low-Volume High-Intensity Interval Training in a Gym Setting Improves Cardio-Metabolic and Psychological Health.
abstract: BACKGROUND
  Within a controlled laboratory environment, high-intensity interval training (HIT) elicits similar cardiovascular and metabolic benefits as traditional moderate-intensity continuous training (MICT). It is currently unclear how HIT can be applied effectively in a real-world environment.
  
  
  OBJECTIVE
  To investigate the hypothesis that 10 weeks of HIT, performed in an instructor-led, group-based gym setting, elicits improvements in aerobic capacity (VO2max), cardio-metabolic risk and psychological health which are comparable to MICT.
  
  
  METHODS
  Ninety physically inactive volunteers (42±11 y, 27.7±4.8 kg.m-2) were randomly assigned to HIT or MICT group exercise classes. HIT consisted of repeated sprints (15-60 seconds, >90% HRmax) interspersed with periods of recovery cycling (≤25 min.session-1, 3 sessions.week-1). MICT participants performed continuous cycling (~70% HRmax, 30-45 min.session-1, 5 sessions.week-1). VO2max, markers of cardio-metabolic risk, and psychological health were assessed pre and post-intervention.
  
  
  RESULTS
  Mean weekly training time was 55±10 (HIT) and 128±44 min (MICT) (p<0.05), with greater adherence to HIT (83±14% vs. 61±15% prescribed sessions attended, respectively; p<0.05). HIT improved VO2max, insulin sensitivity, reduced abdominal fat mass, and induced favourable changes in blood lipids (p<0.05). HIT also induced beneficial effects on health perceptions, positive and negative affect, and subjective vitality (p<0.05). No difference between HIT and MICT was seen for any of these variables.
  
  
  CONCLUSIONS
  HIT performed in a real-world gym setting improves cardio-metabolic risk factors and psychological health in physically inactive adults. With a reduced time commitment and greater adherence than MICT, HIT offers a viable and effective exercise strategy to target the growing incidence of metabolic disease and psychological ill-being associated with physical inactivity.
authors.affiliation: Research Institute for Sport & Exercise Sciences (RISES), Liverpool John Moores University, Liverpool, United Kingdom.
authors.forename: Sam O
authors.initials: SO
authors.lastname: Shepherd
authors.affiliation: Institute for Sport, Physical Activity & Leisure, Carnegie Faculty, Leeds Beckett University, Leeds, United Kingdom.
authors.forename: Oliver J
authors.initials: OJ
authors.lastname: Wilson
authors.affiliation: UBSport Hi Performance Centre, University of Birmingham, Birmingham, United Kingdom.
authors.forename: Alexandra S
authors.initials: AS
authors.lastname: Taylor
authors.affiliation: School of Psychology & Speech Pathology, Curtin University, Perth, Australia.
authors.forename: Cecilie
authors.initials: C
authors.lastname: Thøgersen-Ntoumani
authors.affiliation: Department of Cardiology, Heartlands Hospital, Birmingham, United Kingdom.
authors.forename: Ahmed M
authors.initials: AM
authors.lastname: Adlan
authors.affiliation: Research Institute for Sport & Exercise Sciences (RISES), Liverpool John Moores University, Liverpool, United Kingdom.
authors.forename: Anton J M
authors.initials: AJ
authors.lastname: Wagenmakers
authors.affiliation: School of Exercise & Nutrition Sciences, Deakin University, Geelong, Victoria, Australia.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Shaw
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure; D001823:Body Composition; D015444:Exercise / Q000502:physiology*; D005215:Fasting / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000502:physiology*; D006801:Humans; D007328:Insulin / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D008603:Mental Health; D008660:Metabolism; D009043:Motor Activity; D010101:Oxygen Consumption; D010349:Patient Compliance; D015203:Reproducibility of Results; D057566:Self Report; D013997:Time Factors; D059289:Vascular Stiffness
chemical_list: D001786:Blood Glucose; D007328:Insulin; D008055:Lipids