title: Interval training in men at risk for insulin resistance.
abstract: We compared 3 months of eucaloric (12 kcal/kg/wk) steady state aerobic training (AER) to interval training (INT) in men at risk for insulin resistance. Primary outcomes included oral glucose tolerance testing (OGTT) and HOMA-IR 24 h and 72 h after each participants last exercise session. Secondary outcomes were VO2max, anthropometry, and metabolic syndrome expressed as a summed z-score (zMS). We also performed a sub-analysis for participants entering the trial above and below the HOMA-IR study median. Mean (95% CI) AER ( - 12.81 mg/dl; - 24.7, - 1.0) and INT ( - 14.26 mg/dl; - 24.9, - 3.6) significantly improved 24 h OGTT. HOMA-IR did not improve for AER, but did for INT 24 h and 72 h post-exercise. VO2max improved similarly for both groups. Changes in body mass for INT ( - 2.29 kg; - 3.51, - 1.14), AER, ( - 1.32 kg; - 2.62, 0.58)] and percent body fat [INT, - 0.83%; - 1.62, - 0.03), AER ( - 0.17%; - 1.07, 0.06)] were only significant for INT. When examined as a full cohort, zMS improved for both groups. Upon HOMA-IR stratification, only high HOMA-IR AER showed significant improvements, while both low and high INT HOMA-IR participants demonstrated significant reductions (P<0.05). Eucaloric AER and INT appear to affect fasting glucose, OGTT and VO2max similarly, while INT may have a greater impact on HOMA-IR and zMS.
authors.affiliation: Sport, Health and Exercise Science, Department for Health, University of Bath, Bath, United Kingdom. c.p.earnest@bath.ac.uk
authors.forename: C P
authors.initials: CP
authors.lastname: Earnest
authors.forename: M
authors.initials: M
authors.lastname: Lupo
authors.forename: J
authors.initials: J
authors.lastname: Thibodaux
authors.forename: C
authors.initials: C
authors.lastname: Hollier
authors.forename: B
authors.initials: B
authors.lastname: Butitta
authors.forename: E
authors.initials: E
authors.lastname: Lejeune
authors.forename: N M
authors.initials: NM
authors.lastname: Johannsen
authors.forename: M J
authors.initials: MJ
authors.lastname: Gibala
authors.forename: T S
authors.initials: TS
authors.lastname: Church
mesh_terms: D000328:Adult; D050218:Body Fat Distribution; D015992:Body Mass Index; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology*; D005951:Glucose Tolerance Test; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D024821:Metabolic Syndrome / Q000503:physiopathology / Q000628:therapy; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D057185:Sedentary Behavior; D055105:Waist Circumference / Q000502:physiology