Improvement in dietary habits and regular exercise is considered to be effective in preventing and/or reducing obesity and lifestyle-related diseases. The aim of this study was to analyze the effects of the combination of regular exercise and tea catechins intake on energy expenditure in humans. Fourteen healthy male subjects of 26 to 42 years of age received either a test beverage containing tea catechins or a control beverage without tea catechins for 2 months period; during this period they also engaged in treadmill exercise at a pace of 5 km/hr for 30 min 3 times a week. Energy expenditure in a sedentary condition or during the treadmill exercise was measured after 2 months by indirect colorimetry. Fat utilization for energy expenditure under both sedentary and exercising conditions was significantly increased by the combination of regular exercise and tea catechins intake compared to that by exercise alone.