['Visfatin is a newly characterized protein that is highly expressed in visceral adipose tissue and may play a role in insulin resistance. We investigated the effects of repeated short bouts of high-intensity exercise on plasma visfatin and related metabolic responses.', 'Six young, physically fit men (22.8 +/- 2.3 years; 78.5 +/- 2.3 kg; and body mass index 22.1 +/- 1.2) performed a single session of a running-based anaerobic sprint exercise (7 sets of 6 x 35 m every 10 s, with 1 min rest between sets). Venous blood samples were collected before, immediately after, and 45 and 90 min after exercise to assess plasma visfatin, insulin, glucose, lactate and glutathione responses.', 'After adjustment for postexercise changes in plasma volume, the data indicate a significant increase in plasma visfatin (12.5 +/- 2.0 vs. 26.6 +/- 3.9 ng/ml, p < 0.02), insulin (p < 0.05), and glucose (p < 0.002) concentrations, and homeostasis model assessment of insulin resistance (p < 0.02), immediately after the exercise session. At 45 min of recovery, all metabolic measures, with the exception of lactate, had returned to baseline levels.'] Is plasma visfatin increased after high-intensity exercise?