title: Rapid leptin decrease in immediate post-exercise recovery.
abstract: OBJECTIVE
  Leptin concentrations in humans are known to decrease in response to fasting. The aim of this work was to investigate whether leptin levels might also be modified by exercise-induced negative energy balance.
  
  
  METHODS
  Eight male runners reported in the morning from 0800 to 1200 h for (i) one resting session (sitting) and (ii) one exercise-and-rest session (2 h run and 2 h rest).
  
  
  METHODS
  Plasma leptin, free fatty acids (FFA), glycerol, cortisol and salivary cortisol were assayed in both sessions at 1200 h.
  
  
  RESULTS
  After exercise-and-rest the leptin concentrations were lower than after rest (1.7 +/- 0.1 vs 2.5 +/- 0.2 micrograms/l, P < 0.05), i.e. a mean decrease of 30.3 +/- 4.5% (range 9.5-45.8). Plasma FFA, glycerol and cortisol concentrations increased: FFA 0.78 +/- 0.08 vs 0.18 +/- 0.04 mmol/l, glycerol 0.13 +/- 0.01 vs 0.04 +/- 0.01 mmol/l, and cortisol 428 +/- 36 vs 279 +/- 27 nmol/l. A negative correlation was found between plasma FFA and leptin levels (r = -0.5, P < 0.05) and between plasma glycerol and leptin levels (r = -0.05, P < 0.05). No correlation was found between leptin and cortisol levels.
  
  
  CONCLUSIONS
  In normal subjects with low body fat, a strenuous exercise-and-rest lowers leptin levels by a mean of 30%. A role of lipolysis possibly via increased plasma free fatty acids and glycerol levels is suggested. Cortisol does not seem to be involved.
authors.affiliation: Laboratoire de Biologie Appliquée à l'Education Physique et aux Sports, Université Bordeaux II, France. martine.duclos@biosport.u-bordeaux 2.fr
authors.forename: M
authors.initials: M
authors.lastname: Duclos
authors.forename: J B
authors.initials: JB
authors.lastname: Corcuff
authors.forename: A
authors.initials: A
authors.lastname: Ruffie
authors.forename: P
authors.initials: P
authors.lastname: Roger
authors.forename: G
authors.initials: G
authors.lastname: Manier
mesh_terms: D000328:Adult; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005990:Glycerol / Q000097:blood; D006801:Humans; D006854:Hydrocortisone / Q000032:analysis / Q000097:blood; D020738:Leptin; D008297:Male; D011506:Proteins / Q000378:metabolism*; D012463:Saliva / Q000737:chemistry; D018709:Statistics, Nonparametric
chemical_list: D005230:Fatty Acids, Nonesterified; D020738:Leptin; D011506:Proteins; D005990:Glycerol; D006854:Hydrocortisone