The only down side to HIIT is that it cannot be performed too many times per week without having an overtraining effect. Since HIIT has many of the same effects of a weight training session it can strain the central nervous system. For this reason you will want to keep HIIT to two 10-20 minute sessions per week. These two sessions should be performed on your non weight training days and should be treated just like your weight training sessions as far as nutrition is concerned.
Low-calorie diets: It is harmful to reduce your daily calorie intake lower than 1400 calories per day, because your body adjusts to a semi-starvation state and looks for alternative sources of energy. In addition to burning fat, your body will eventually burn muscle tissue. Because your heart is a muscle, prolonged starvation will weaken it and interfere with its normal rhythms. Low-calorie diets don't meet the body's nutrition needs, and without nutrients your body cannot function normally.
Many patients will be in pain and have a loss of appetite after surgery. Part of the body's response to surgery is to direct energy to wound healing, which increases the body's overall energy requirements. Surgery affects nutritional status indirectly, particularly during the recovery period, as it can interfere with wound healing and other aspects of recovery. Surgery directly affects nutritional status if a procedure permanently alters the digestive system. Enteral nutrition (tube feeding) is often needed. However a policy of 'nil by mouth' for all gastrointestinal surgery has not been shown to benefit, with some suggestion it might hinder recovery.[needs update]
This may explain why the fat-burning effects of eating more protein were confirmed in a study published in the American Journal of Physiology. One group was fed a high-protein diet (just over 1 gram per pound of body weight per day) while the second group consumed an amount closer to the lower recommendation of the RDA (recommended dietary allowance). The group eating the higher-protein diet burned the most fat.