Strength training is anaerobic exercise, which means that your muscles are burning primarily glucose for energy. Glucose is found in foods that contain carbohydrates. Ketosis is a metabolic state that occurs when your body is deprived of glucose. In the absence of glucose, your body begins to burn stored body fat quickly, which produces ketones. During your workouts, you are able to burn some ketones and protein for energy, but they are not an optimal fuel source for your muscles. Consult with your health care provider before beginning any diet or exercise program.
Being in ketosis negatively affects your exercise performance. Because of the intensity of strength training, your muscles have an increased demand for glycogen, the stored form of glucose. Severe carbohydrate restriction completely depletes your stored glycogen in both your liver and your muscles. The end result is that during your workouts, your muscles feel weak and tire prematurely.
Your strength training workouts damage your muscles at a cellular level. Immediately after you finish working out, your body begins to repair the damage to your cells by a process called protein synthesis. During protein synthesis, your cells require adequate amounts of amino acids from protein. When you are in ketosis, during your workouts your cells burn ketones and amino acids for energy. This utilization of amino acids for energy during your workouts, means that less amino acids are available for the repair process. Ultimately, if your muscles fail to recover and repair properly, it will hinder your ability to gain muscle and increase your strength.
Cyclical Ketogenic Diet
A cyclical ketogenic diet, CKD, is a general term for a series of diets that are widely used by natural bodybuilders. These types of diet plans consist of weekly cycles that involve five to six days of severe carbohydrate restriction, with the intention of going in to ketosis. The days of restriction are followed by one to two days of excessive carbohydrate consumption. The purpose of the CKD is to maximize fat loss, while maintaining adequate glycogen stores. Having adequate glycogen helps to maintain the intensity of your workouts. While you are on a CKD, you will primarily be strength training, along with a moderate amount of aerobic exercise.
When you are in ketosis, the level of ketones in your blood becomes so high that they spill off in to your urine. Consequently, your urine becomes very thick, and concentrated. It is important to drink a minimum of eight glasses of water daily to prevent urinary tract infections. Discuss with your health care provider regarding your specific fluid needs while in ketosis.
- Columbia University; Go Ask Alice; Do Bodybuilders and Other Weightlifters Need More Protein?; May 28, 1999
- Mesomorphosis.com; Training on the Cyclical Ketogenic Diet-Effects of Cyclical Ketogenic Diets on Exercise Performance; Lyle McDonald
- Vanderbilt University; The Key to Ketogenic Diets; Anna Temlock