The purpose was to determine if an intense interval training session could produce transient pulmonary edema in women. Fourteen females [(27+/-4 years; body mass index of 21.6+/-1.5 kg/m(2)); maximal oxygen consumption = 3.12+/-0.42 L/min] performed three sets of 5 min sea-level cycling exercise with 10-min recovery between each set. Average oxygen consumption at minute 5 of each set was 96+/-5% of maximum and arterial plasma lactate concentration at minute 5 of each set was 16.0+/-3.3 mmol/L. Chest radiographs were obtained before and 33.2+/-6.1 min after exercise. Four different chest radiologists independently reviewed the radiographs for edema, and scored seven validated radiographic characteristics on a three-point scale (0-2). The overall edema score increased from 1.3+/-1.6 before exercise to 1.9+/-2.0 after exercise [P<0.05; Delta = +0.7+/-1.8, 95% CI, 0.2 to +1.1]. This study shows that an intense interval training session can cause mild, detectable pulmonary edema in some women.