Leptin and adiponectin are two insulin-sensitizing adipokines that may be influenced
transiently by exercise and contribute to the post-exercise improvement in insulin-mediated
glucose uptake. The influence of exercise on these adipokines is inconsistent and confounded by
a variety of factors. Therefore, the purpose of this study was to characterize the temporal
responses of adipokines to repeated exercise bouts in successive days in obese males with
metabolic syndrome and their relationship with markers of insulin resistance. Exercise sessions
were completed by expending 350 kcals of energy, walking on a treadmill at 60 to 70% of V.
max, on each of four successive days. Blood samples from eleven middle-aged men (Age: 50
8.0 years, BMI = 32.0 4.6 kg/m2
, % Fat = 29 4.0 (% of body weight), VO2max = 28.9 4.3
kg.-1min-1, SBP = 140 ± 8.6 mmHg, DBP = 92 ± 6.3 mmHg, triglyceride = 267 ± 145.0
mg/dL, HDL-C = 32 ± 5.0 mg/dL, glucose = 99.6 ± 12.8 mg/dL) were obtained before each
exercise session and obtained again at 24 and 72 hours after the last exercise bout. Changes in
plasma volume-adjusted total and HMW adiponectin, leptin, NEFA, glucose and insulin were
determined using multiple 1 x 6 repeated-measures ANOVAs. Insulin concentrations decreased
26% with a single bout of exercise. Leptin decreased 9% after two exercise sessions and
remained lower up to 24 hours following the last exercise session. NEFA, glucose, the HOMA
score, adiponectin and HMW adiponectin remained unaltered with exercise. The accumulated
effect of multiple bouts of exercise in leptin concentrations was greater than the effect obtained
from two exercise bouts but not related to changes in insulin concentrations or the HOMA score.
Leptin changes following exercise may contribute to lower insulin resistance following exercise
but is not necessary for the reduced insulin resistance observed after exercise.