An important step in optimizing a training diet is to make sure that the athlete consumes enough carbohydrates, proteins and fats.

People who follow a general fitness program need about the same amount of nutrients as the average person.
(i.e. 45-55% carbs, 3-5g/kg/day;
10-15% fat, 0.8-1.0 g/kg/day;
and 25-35% protein, 0.5-1.5 g/kg/day).

With a large and medium volume of training, athletes should include more carbohydrates and proteins in the diet. For example, athletes who do a moderate amount of intense training (2-3 hours a day of intense exercise 5-6 times a week) typically need 55-65% carbohydrate in their diet (5-8 g/kg/day or 250-1200 g/day for athletes weighing 50-150 kg), in order to maintain proper levels of glycogen in the liver and muscles.

Research has also shown that athletes at high volume, intense training (3-6 hours per day for 1-2 workouts per day, 5-6 days per week) need 8-10 g/day/kg of carbohydrates (400-1500 g/kg).day for athletes weighing 50-150 kg) to maintain proper muscle glycogen levels.

This is equivalent to eating about 0.5-2.0 kg of spaghetti. Preference should be given to complex carbohydrates (for example, whole grains, etc.). However, taking this amount of carbs with regular meals can be physically demanding, which is why many experts recommend drinks or other concentrated carb supplements (such as weight gainers). Consuming this amount of carbohydrates is not necessary for regular fitness activities (training 3-4 times a week for 30-60 minutes), but it is necessary for high and medium intensity training.

The American College of Sports Medicine (ACSM) recommends taking 0.7g/kg/hour during exercise as a 6-8% solution (6-8 grams of carbs per 100 ml of fluid). With this approach, the consumption of carbohydrates per hour will be 30-70 grams for an athlete weighing 50-100 kg. Studies have also shown that eating more carbohydrates does nothing to increase the amount of carbohydrates that the body has time to oxidize. It has also been noted that the rate of oxidation may vary depending on the type of carbohydrates consumed, as they are transported by different transporters. For example, the rate of oxidation of disaccharides and polysaccharides such as sucrose, maltose and maltodextrins is high, while fructose, galactose, trehalose and isomaltulose are, on the contrary, low.

The combined intake of glucose and sucrose, or maltodextrin and fructose, produced the highest rate of oxidation of any carbohydrate intake studied.

In these studies, a ratio of 1-1.2 maltodextrin to 0.8-1.0 fructose was used. For this reason, we recommend paying attention to the type of carbohydrates you take before, during, and after your workouts to increase their availability in the body.

It should be remembered that these recommendations are relevant for those sports where it is important to achieve maximum physical performance (boxing, running, cycling, etc.). In bodybuilding, carbohydrates with high bioavailability (sugars, maltodextrin) will be stored in fat, since the energy costs of this sport are relatively low. Experts recommend eliminating fast carbohydrates altogether, even while gaining muscle mass, or reducing consumption to a minimum.

Abuse of carbohydrates

Frequent and high consumption of carbohydrates has been shown in studies to have a negative effect on the sensitivity of insulin receptors, leading to an increase in insulin levels. A chronic rise in insulin due to frequent carbohydrate intake throughout the day can increase insulin resistance towards the end of the day. Decreasing carb intake and alternating between low carb days and moderate carb days can help stabilize insulin levels and promote effective fat loss.