Introduction: Ghrelin and obestatin are orexigenic/anorexigenic peptides secreted from the gastrointestinal tract. Obestatin, a 23 amino acid peptide, was recently discovered and isolated from rat stomach. .Objective: The aim of this study was to investigate how an anaerobic interval exercise would affect plasma obestatin and hormonal responses. Material and Methods: Twenty-five young female college students were assigned into control (19.5 ±0.27 yr, 163.25±0.62 cm, 58.81±1.96kg, 22.05±0.67 BMI, 39.07±2.8 ml/kg.min, n= 10) and Running-based anaerobic sprint test (RAST)(20±0.4yr, 161.88±0.78cm, 54.22±1.80kg, 20.66±0.58 BMI, 42.63±1.23 ml/kg.min, n=15) groups. Individuals in the training group performed 5 sets of Running-based Anaerobic Sprint Tests (RAST), each set consisting of 6×35 meter sprints. Intervals between each 35 meter sprint and set of 6 sprints were 10 seconds and 5 minutes respectively. Blood samples from overnight fast and luteal phase individuals from both groups were obtained pre-, and at specified intervals, post- 6 consecutive days of RAST exercise training. Plasma levels of obestatin, glucose, growth hormone, insulin, Cortisol, testosterone, and DHEA-S were determined. Results: No significant changes in plasma obestatin levels were observed (P<0.473). A significant reduction in GH, and testosterone plasma levels were noted in the RAST training groups (P<0.032, P<0.043). Changes in insulin, Cortisol, and DHEA-S were not significant. Discussion our results indicate that the effect of high intensity exercise on plasma obestatin and other measured variables was attenuated by short term fasting and a combination of obestatin and lactate changes together may lead to an anorexigenic condition in the RAST group |