Kissing burns about 68 calories per hour. If it involves petting and is fairly strenuous, it often burns up to 90 calories per hour, according to sex expert Jaiya Kinzbach.
Kinzbach recommends kissing in unconventional positions and even incorporating traditional exercises, such as push-ups, into the act to burn even more calories while kissing. Passionate, vigorous kissing sessions are apt to burn up to two calories per minute. However, this is not as effective as using a treadmill at moderate intensity, which burns about 11 calories per minute. Physicians note that while kissing and sex cause the heart to beat as a result of increased adrenaline, they are not replacements for conventional cardiovascular exercise.