Effect of energy expenditure and training status on leptin response to sub-maximal cycling

We examined the leptin response and related hormones duringand after two sub-maximal exercise protocols in trained anduntrained subjects. during this study, plasma concentrations ofleptin [lep], insulin [i], cortisol [c], growth hormone [gh],glucose [g] and lactate [la] were measured. 7 elite volleyballtrained players (tr) and 7 untrained (utr) subjects (percentbody fat: 13.2 ± 1.8 versus 15.7 ± 1.0, p < 0.01, respectively)were examined after short and prolonged sub-maximal cyclingexercise protocols (sp and pp). venous blood samples werecollected before each protocol, during, at the end, and after 2and 24 h of recovery. sp and pp energy expenditures rangedfrom 470 ± 60 to 740 ± 90 kcal for tr and from 450 ± 60 to 710± 90 kcal for utr, respectively. [lep] was related to body fatpercentage and body fat mass in tr (r = 0.84, p < 0.05 and r =0.93, p < 0.01) and in utr (r = 0.89, p < 0.01 and r = 0.92, p <0.01, respectively). [lep] did not change significantly duringboth protocols for both groups but was lower (p < 0.05) in allsampling in tr when compared to utr. plasma [i] decreased(p < 0.01) and [gh] increased (p < 0.01) significantly duringboth sp and pp and these hormones remained lower (i: p < 0.01)and higher (gh: p < 0.01) than pre-exercise levels after a 2-hrecovery period, returning to base-line at 24-h recovery. plasma[la] increased (p < 0.01) during both protocols for tr and utr.there was no significant change in [c] and [g] during and afterboth protocols for all subjects. it is concluded that 1) leptin isnot sensitive to acute short or prolonged sub-maximal exercises(with energy expenditure under 800 kcal) in volleyball/anaerobically trained athletes as in untrained subjects, 2)volleyball athletes showed significantly lower resting and exerciseleptin response with respect to untrained subjects and 3) itappears that in these anaerobically trained athletes leptinresponse to exercise is more sensitive to the level of energyexpenditure than hormonal or metabolic modifications inducedby acute exercise.