title: Intensity of acute exercise does not affect serum leptin concentrations in young men.
abstract: OBJECTIVE
  We examined the effects of exercise intensity on serum leptin levels.
  
  
  METHODS
  Seven men (age = 27.0 yr; height = 178.3 cm; weight = 82.2 kg) were tested on a control (C) day and on 5 exercise days (EX). Subjects exercised (30 min) at the following intensities: 25% and 75% of the difference between the lactate threshold (LT) and rest (0.25 LT, 0.75 LT), at LT, and at 25% and 75% of the difference between LT and VO2peak (1.25 LT, 1.75 LT).
  
  
  RESULTS
  Kcal expended during the exercise bouts ranged from 150 +/- 11 kcal (0.25 LT) to 529 +/- 45 kcal (1.75 LT), whereas exercise + 3.5 h recovery kcal ranged from 310 +/- 14 kcal (0.25 LT) to 722 +/- 51 kcal (1.75 LT). Leptin area under the curve (AUC) (Q 10-min samples) for all six conditions (C + 5 Ex) was calculated for baseline (0700-0900 h) and for exercise + recovery (0900-1300 h). Leptin AUC for baseline ranged from 243 +/- 33 to 291 +/- 56 ng x mL(-1) x min; for exercise + recovery results ranged from 424 +/- 56 to 542 +/- 99 ng x mL(-1) x min. No differences were observed among conditions within either the baseline or exercise + recovery time frames. Regression analysis confirmed positive relationships between serum leptin concentrations and percentage body fat (r = 0.94) and fat mass (r = 0.93, P < 0.01).
  
  
  CONCLUSIONS
  We conclude that 30 min of acute exercise, at varying intensity of exercise and caloric expenditure, does not affect serum leptin concentrations during exercise or for the first 3.5 hours of recovery in healthy young men.
authors.affiliation: Department of Human Services, University of Virginia, Charlottesville, USA. alw2v@virginia.edu
authors.forename: A
authors.initials: A
authors.lastname: Weltman
authors.forename: C J
authors.initials: CJ
authors.lastname: Pritzlaff
authors.forename: L
authors.initials: L
authors.lastname: Wideman
authors.forename: R V
authors.initials: RV
authors.lastname: Considine
authors.forename: D A
authors.initials: DA
authors.lastname: Fryburg
authors.forename: M E
authors.initials: ME
authors.lastname: Gutgesell
authors.forename: M L
authors.initials: ML
authors.lastname: Hartman
authors.forename: J D
authors.initials: JD
authors.lastname: Veldhuis
mesh_terms: D000328:Adult; D004734:Energy Metabolism; D015444:Exercise / Q000502:physiology*; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D010807:Physical Endurance
chemical_list: D020738:Leptin