title: A single session of low-intensity exercise is sufficient to enhance insulin sensitivity into the next day in obese adults.
abstract: OBJECTIVE
  The purpose of this study was to determine the effect of a relatively modest session of exercise on insulin sensitivity and fatty acid uptake the next day in obese adults.
  
  
  METHODS
  Eleven sedentary obese adults (male/female: 3/8; BMI 37 ± 1 kg/m(2); peak oxygen uptake [VO2peak] 20 ± 1 mL/kg/min) completed three experimental trials. On two of these occasions, subjects exercised to expend 350 kcal in the afternoon. These two exercise trials were identical except for the exercise intensity (50% VO2peak [EX50] and 65% VO2peak [EX65]) and the duration of exercise necessary to expend 350 kcal (EX50 = ≈ 70 min; EX65 = ≈ 55 min). Subjects also completed a control trial (CON), without exercise. The next morning, we measured insulin sensitivity (hyperinsulinemic-euglycemic clamp) and whole-body fatty acid uptake (palmitate rate of disappearance from plasma [Rd]).
  
  
  RESULTS
  Exercise increased insulin sensitivity the next day, but whereas the 35% improvement after EX50 compared with CON was statistically significant (P = 0.01), the 20% improvement after EX65 was not (P = 0.17). Despite nearly identical values between CON and EX65 (P = 0.88), systemic fatty acid uptake was lower after EX50 compared with EX65 (P = 0.02), but not quite significant compared with CON (P = 0.07). Importantly, the change in fatty acid uptake after exercise compared with CON was negatively correlated with the change in insulin sensitivity for all trials (r = -0.60, P = 0.003).
  
  
  CONCLUSIONS
  A relatively modest single session of exercise in obese adults improved insulin sensitivity the next day, and a reduction in systemic fatty acid uptake in the several hours after exercise may be important for this effect.
authors.affiliation: Substrate Metabolism Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Sean A
authors.initials: SA
authors.lastname: Newsom
authors.forename: Allison C
authors.initials: AC
authors.lastname: Everett
authors.forename: Alexander
authors.initials: A
authors.lastname: Hinko
authors.forename: Jeffrey F
authors.initials: JF
authors.lastname: Horowitz
mesh_terms: D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005081:Exercise Therapy; D005260:Female; D015309:Glucose Clamp Technique; D006801:Humans; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood* / Q000628:therapy; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin