Biochemical Foundations of Human Vital Activity - Volkov N.I., Nesen E.N. 2000

Biochemistry of Sports
Biochemical Foundations of Athletes' Rational Nutrition
Dietary Supplements and Weight Management

During periods of intensive training, competitions, and athletic recovery, it is quite challenging to replenish energy expenditures (3000–7000 kcal) and support biosynthetic processes through regular meals alone. Therefore, special high biological value products (HBVP) or dietary supplements with varying nutritional and chemical compositions have been developed for athletes. Such products are highly concentrated, calorie-dense, and target specific metabolic pathways—protein, carbohydrate, fat, or vitamin-mineral—with distinct performance goals:

✵ increasing Muscle mass;

✵ optimizing body composition (reducing fat mass while increasing muscle and bone mass);

✵ enhancing metabolic rate and energy production;

✵ restoring electrolyte balance;

✵ activating regulatory mechanisms of METABOLISM/26.html">Energy Metabolism and other metabolic processes;

✵ reducing body weight, etc.

High biological value products are used in sports to correct imbalanced daily diets, fuel athletes during events and between training sessions, accelerate recovery, and manage body weight.

To build strength and speed—that is, to increase muscle mass during training—protein supplements are used, such as SP-11 coffee, chocolate, and fruit "Multikrafka", "Astrofit", and many other protein-rich complexes.

To provide the body with energy during prolonged endurance training and competitions, HBVPs are used that contain high amounts of CARBOHYDRATES, as well as fats and Vitamins that enhance The oxidation of energy substrates. Their small serving size delivers sufficient energy to the body while relieving high nervous tension in athletes. Examples include "Olimp" biscuits and "Bodrost" halva, among others.

For sports disciplines where physical exertion is accompanied by significant fluid loss, special carbohydrate-mineral drinks such as "Spartakiada", "Isotonic", and "Olimpik" are used. Between training sessions, these drinks are consumed in small portions—20–25 ml, with a total volume of 50–60 ml and a mineral concentration of 6–10%. After training or competition, fluid intake may be increased.

Weight management is most frequently associated with weight loss and is achieved by reducing energy intake (calories) and/or increasing Energy Expenditure. In athletic practice, body weight can be reduced by increasing the volume of training loads (energy expenditure) and, strictly in sports with high training frequencies, by lowering caloric intake. However, a drastic reduction in food calories is not recommended, as it leads to a drop in athletic performance: the body loses large amounts of Water and minerals, Glycogen stores are depleted, and structural and contractile muscle components break down.

The best approach to weight loss is a combination of a gradual reduction in dietary calories with increased energy expenditure during training. With this weight management strategy, muscle mass remains unchanged while fat mass decreases, which has no negative impact on athletic performance. However, weight loss should not exceed 0.5–1.0 kg per week, which is achieved by cutting calories by 200–500 kcal per day combined with exercise.

Sometimes, rapid weight-cutting ("making weight") is used by restricting fluid intake and increasing water loss through sweat. Such a practice is undesirable for athletes as it leads to reduced Blood volume, electrolyte loss, depletion of muscle and Liver glycogen, and impaired renal function and thermoregulation. As a result, muscle strength and overall performance decline. Specialized products known as "fat burners" have been created for weight management; they contain energy metabolites as well as carnitine, which facilitates fat breakdown (for more details, see specialized literature).

Review Questions

1. What nutrient groups are essential for humans?

2. What are the Basic principles of A balanced diet for athletes?

3. What are the energy expenditures of manual laborers and athletes in specific sports? What do they depend on?

4. What is The Role of carbohydrates in an athlete's diet, and what are their recommended intake levels?

5. What is the role of specific classes of fats in supporting physical performance? What are the specific considerations for using fats in athletic Nutrition?

6. What are the protein intake standards for athletes in various sports? What constitutes the Biological value of dietary protein?

7. What are the recommended vitamin intake levels and the objectives of their use in specific sports? How are Vitamin Requirements met during physical training?

8. What are the specific Characteristics of Carbohydrate nutrition during training, competition, and recovery?

9. What are the nutritional approaches during physical exertion? What is the rationale behind them?

10. For what purposes are HBVPs used in sports?

11. What processes are involved in The regulation of body weight?