Elísabet Margeirsdóttir, nutritionist and running queen, is one of the authors of the article. mbl. is / Eggert Jóhannesson
High-carb diets and fasting have been prominent in the public discourse and have even been promoted as improving the health and performance of athletes, but in terms of athletic performance it is of little significance and may be inhibiting.
This is written by a professor, assistant professor, associate professor and two lecturers in the department of health promotion, sports and leisure, School of Education, University of Iceland, together with Elísabeta Margeirsdóttir, running queen and nutritionist, in a letter in the latest issue of Læknablaðið .
Sigríður Lára Guðmundsdóttir Associate Professor, Birna Varðardóttir Assistant Professor, Gréta Jakobsdóttir Assistant Professor, Vaka Rögnvaldsdóttir lecturer and Anna Sigríður Ólafsdóttir professor, write together with Elísabeta that due to the body’s almost unlimited supply of fat, it is claimed that it is possible to increase performance in endurance sports by increasing the share of fat mentioned. black in the diet at the expense of carbohydrates or even skipping food intake for a certain period of time. The body’s fat burning capacity can increase considerably on such a diet, but in terms of performance in sports it has little significance and can be inhibitory. It is important that training and nutrition recommendations are based on proven methods and quality research.
Research samples does not require a permanent effect of a low carb diet 1108097
Says in the article that a low carb diet can lead to concomitant weight loss, but that research has not conclusively shown that it has a greater or more lasting effect than other dietary changes. The long-term effects of fasting are little known. Intermittent fasting can cause loss of both fat and muscle mass, seems to have a positive effect on energy metabolism and blood sugar control, but longer fasting is considered detrimental to health and capacity.
At rest or with very little, long-term enthusiasm, the body primarily uses fat as an energy source, but with increased exercise, it uses proportionally more carbohydrates from glycogen stores, which are therefore an important source of energy. in training and competition of endurance disciplines.
There are few indications of better results in endurance sports Few studies suggest that a low-carb diet improves performance in endurance sports. It significantly promotes increased fat burning capacity but also appears to inhibit the utilization of carbohydrates as an energy source during exercise. Furthermore, the effect of fasting on performance in sports seems negative with regard to high-intensity training and maintenance of muscle mass.
Finally, restriction of food or energy can lead to a relative energy shortage, which has far-reaching effects, m including metabolic rate, hormone activity and the menstrual cycle of women, bone health, immune protection, protein synthesis and cardiovascular function.
Relative energy deficiency thus has a negative effect on health and athletic performance in the long and short term, not only among high-achieving athletes because the problem can occur regardless of age and ability level. It can also increase the risk of injury and delay recovery and thus inhibit further exercise.
“Given the serious health problems caused by osteoporosis and muscle wasting, it is advisable to recommend a low-carb diet or fasting along with intensive training, especially with increasing age. Fasting and / or exclusion of individual foods or energy substances are at odds with nutritional recommendations for adults. An abnormal relationship with food reduces the experience and well-being associated with eating and can even lead to eating disorders. It is important to keep in mind the purpose of training and nutrition and whether the goals are related to performance, health, physical condition or well-being. We see reason to point out the importance of athletes seeking training and nutrition counseling from competent bodies with appropriate education and qualifications, such as trained sports and nutritionists. “
It is especially worth noting that research on fasting among athletes has almost all been done on young healthy people where bone density and muscle mass are at their peak. In addition, most studies on the effects of fasting or following a low-carb diet on fat, muscle, and bone mass have been requested by overweight people. The effect on other age groups and people of ideal weight who do a lot of exercise or sports is likely to be different.