Purpose: The aim of this study was to determine if High Intensity Interval Training (HIIT) results in a higher energy expenditure and is more enjoyable when compared to moderate exercise. Methods: On two different days, ten college age men and women exercised on a treadmill at either 50% of their maximum heart rate for 20 consecutive minutes or 90% of their maximum heart rate for one minute, alternated by one minute of recovery walking, which was repeated 10 times for a total of 20 minutes of exercise. Heart rate and calories burned were assessed with a heart rate monitors. Assessments were continued during a 30-minute recovery period as participants sat quietly in a chair. PACES, a survey based on enjoyment of the exercise was also completed. Results: Moderate exercise burned an average of 139±40 calories while exercising and 64±15 calories during recovery. HIIT burned an average of 204±40 calories while exercising and 117±47 calories during recovery. The PACES score for moderate exercise was 14.2 while HIIT was 12.5, which was not statistically different and indicates no difference in enjoyment between the conditions. Conclusion: HIIT is the more effective way to burn more calories during exercise and after exercise given the same time period as moderate exercise.