The intake of carbohydrates and their role in the diet of physically active people is always a matter of many disputes. Debates on this subject can be heard at numerous gyms around the world, and scientific publications also do not avoid controversy and convergent information. Low carbohydrate diets are widely used by a wide range of body builders preparing for competition and seeking to maximize fat loss. Among people who care about the appearance of the figure also raises the fear of losing muscle mass during the use of such a diet. Disciplines regarding carbohydrate intake after training and low carbohydrate diets are explained in the text below.
Fitness and health
The subject of diets including low carbohydrate intake is covered by many controversies, especially regarding the cardiovascular system. Dr Dena Bravata from Stanford University conducted a meta-analysis of 94 dietary interventions published in scientific articles investigating the impact of carbohydrate restrictions on health indicators. The general conclusion of the analysis was the beneficial effect of low carbohydrate diets on the markers of metabolic syndrome or its absence.
Although the initial associations often combine low-carbohydrate diets with reduction of efficiency and muscle mass, this empirical scientific study creates a different picture. Research conducted by Dr. Jeff Volek at the University of Connecticut shows that diets in which the supply of carbohydrates does not exceed 50 grams, in many cases allow for better retention of dry body weight, as well as improve fat metabolism. The necessary condition for such results is the isocalorality of the compared diets, i.e. their alignment in terms of calories provided. Cutting down calories without supplementing their supply with protein and fats will result in a low-calorie diet that will prevent the retention of dry body mass and the optimization of sports results.
Dr Volek also showed that the reduction in carbohydrate content in the diet, it improves fat utilization processes during aerobic training. The result may be improved performance during endurance training.
Glycogen and energy reserves after training
The alleged requirement to consume carbohydrates, especially during the post-exercise period, is largely due to the belief in the importance of insulin in the transport of amino acids and the impact of this hormone on muscle mass. Although carbohydrates are the most important ingredient stimulating insulin secretion, the same leucine supply – one of the most important branched chain amino acids – is a factor that also stimulates the pancreas to release the insulin hormone. Consuming sources of leucine-rich protein, a good example of which is a protein supplement, allows a significant insulin release.
Recommendations regarding high carbohydrate intake are directed especially at the post-workout period, because then it is possible to rapidly replenish the glycogen stores accumulated in muscles. However, this is not so obvious. The complete depletion of carbohydrate stores in the muscles is common mainly after the completion of long-term endurance training.
Strength training does not require the use of glycogen as it may seem. A study conducted by Dr. Duncan Macdougall showed that a single series of flexing the arm with a dumbbell depletes glycogen in 12%, while the 3 series of this exercise led to exhaustion in 24%. Strength training leads, on average, to the depletion of glycogen in 40% of the muscle mass being trained.
Although the post-workout meal plays an important role in supplementing glycogen, assuming that carbohydrates appear in the remaining meals during the day, it will still lead to full glycogen resynthesis within 8 or 24 hours after finishing the training unit.
Protein and muscle mass
Carbohydrates are widely perceived as macronutrients that enable the development of muscle mass, but all tests to check their effectiveness show that they are not able to initiate the muscle protein synthesis process when compared to protein. Dr. Aaron Staples of the University of McMaster showed that 25 grams of protein has the same effect on anabolism markers as the combination of 25 grams of protein and 50 grams of carbohydrates.
Consumption of carbohydrates leads to the discharge of insulin, which allows maximizing the synthesis of muscle proteins. However, as already mentioned in the article, protein sources rich in amino acid leucine guarantee insulin release required to maximize the synthesis of muscle proteins and minimize the degradation of muscle proteins.