Exercise is an easily accessible and inexpensive approach to improve cardiovascular health, control weight gain, and increase survival chances after a morbid event such as a myocardial infarction. It is, however, sometimes associated with untoward effects in vulnerable subjects. A contributory factor may be heart rate variability, which in the long term is increased in association with exercise, but may be decreased in the short term during exercise and the recovery span after exercise. Brno Consensus under the leadership of Professor F. Halberg, G. Cornélissen, Professor T. Kenner, Professor B. Fiser, Dr. J. Dušek and me (Brno chronobiological team) described Vascular Variability Disorders (VVDs), associated with a statistically significant increase in cardiovascular disease risk, include in addition to a high blood pressure other alterations of the variability in blood pressure and/ or heart rate. Among others, an excessive circadian amplitude (CHAT) of BP was shown to dramatically increase cardiovascular disease risk.