The ability to make long-term efforts is determined to a great extent by high potential aerobic capacity, the availability of energy substrates , the enzymatic activity and the efficiency of thermoregulation and the cardiorespiratory system.
These skills are a fundamental basis necessary to evaluate the level of physical fitness of an athlete and are conditioned by various factors, among which genetics, training regimen, nutrition and body composition should be underlined. Furthermore, it should be emphasized that intensive training, nutritional mismatch and mental stress, lead to muscle fatigue and damage, as well as oxidative stress, which shape the specific nutritional needs of physically active people.
What does an endurance athlete need?
Endurance sports are becoming increasingly popular and athletes of all skill levels are looking for ways to optimize their performance through training and nutrition.
Per endurance exercise lasting 30 minutes or more, the factors most likely to contribute to fatigue are dehydration and glycogen depletion, while gastrointestinal problems, hyperthermia, and hyponatremia can reduce exercise performance. endurance exercise and are potentially dangerous to health, especially in longer events (>4 h).
While high initial muscle glycogen concentrations may be beneficial for endurance exercise, this need not be achieved by the traditional supercompensation protocol. A personalized nutritional strategy can be developed that aims to deliver carbohydrates to the working muscle at a rate that depends on the absolute exercise intensity and duration of the event.
Endurance athletes should attempt to minimize dehydration and limit body mass losses through perspiration to 2-3% of body mass. Gastrointestinal problems occur frequently, especially in long distance races. The problems appear to be highly individual and perhaps genetically determined, but may also be related to the intake of highly concentrated carbohydrate solutions, hyperosmotic beverages, as well as fiber, fat and protein intakes. Hyponatremia has occasionally been reported, especially among slower competitors and therefore with very high consumption of water or other low sodium beverages.
The role of nutrition in the cyclist
Good nutrition is important at every stage of training and competition. Both the serious competitive cyclist and the recreational cyclist should follow a balanced diet that provides adequate calories to meet energy needs. Athletes who consume less than 2000 calories per day may find it difficult to meet nutrient needs, particularly for iron and calcium. Weight loss, glycogen depletion, and dehydration are also possible results of an inadequate diet.
Dietary strategies to improve or maintain the body's carbohydrate stores are necessary for performance, especially for cyclists with high training miles or who participate in road races and other endurance events. Additionally, cyclists should be encouraged to drink plenty of fluids , especially when in a hot environment.
It appears that the protein requirement of endurance athletes increases with increasing duration and intensity of exercise. However, factors such as total calorie intake and protein quality should be considered when determining your protein needs. Many athletes are concerned about their vitamin and mineral intake and often use nutritional supplements for both " health insurance " and performance reasons .
The most commonly taken supplements include vitamin C, B-complex and iron. Vitamins and minerals in excess of the RDA do not improve performance and can be toxic when consumed in large quantities. On the other hand it should be considered that vegetarians and cyclists with low calorie intakes can benefit from a multivitamin or mineral supplement.
How important is body composition for a cyclist
Furthermore, another important aspect from the point of view of endurance sports training is that of achieving and maintaining an adequate nutritional status. In this regard, the key factor providing information on nutritional status is the body composition together with the analysis of the concentration of selected clinically relevant biochemical markers (eg, in blood, saliva, urine) should be prominently indicated.
Monitoring athletes' body composition indicators allows, among other things, to evaluate the effectiveness of dietary and training interventions . On the other hand, manipulation of body composition allows for the support of physical performance, the adaptation to the requirements of a given sport discipline and the assumption of high intensity exercise loads. Similarly, an important element is also the assessment of nutritional status which involves analyzing the balance of selected nutrients, especially over a longer perspective and time.
A recent study, published in December 2022, analyzed the behavior of a large group of endurance athletes (about 50) by assessing their nutritional conditions (analysis of nutrients taken with the diet of the period considered and body composition). These are the results:
- Body mass decreased slightly from 80.5 ± 14.4 kg in the training period to 78.6 ± 11.2 kg in the competition period, mainly due to the insignificant reduction in body fat, therefore related to a significant loss of lean mass;
- Compared with the recommendations, the studied group provided lower energy (recommended ≥40 kcal/kg BM/day) and carbohydrate (recommended ≥6 g/kg BM/day), as well as vitamin E (recommended 15 mg/day, 85 % of participants not meeting recommendations in both periods) and folic acid (400 µg/day recommended; 85 and 80% of participants not meeting recommendations in training and competition period, respectively) during both periods;
- Furthermore, during the training period, the athletes did not meet their vitamin C requirements (75 mg/day recommended; 60% of athletes do not meet the recommendations) and during the soccer competition period (1000 mg/day recommended ; 65% of participants do not meet the recommendations).
Evaluation of the nutritional value of the diet indicates that the athletes studied did not periodize their diet according to the training cycle (training period vs. competition).
During the competition period, athletes performed the incremental exercise test significantly longer (p = 0.025) than during the training period. Additionally, %VO 2max_VT decreased (p = 0.047) during the competition period. However, the lack of changes in relative VO 2 absorption to VT may limit the clinical significance of the above %VO 2max_VT changes. In addition, there were also no significant improvements in the rate of other cardiorespiratory peaks and thresholds.
Although there were no differences in the dietary intake of minerals and vitamins in the study group between the training and competition periods in this study, there were several deficiencies. In both training periods, the energy value of the diet of the athletes studied, as well as the intake of carbohydrates and folic acid, were lower than the recommendations. Furthermore, the intake of vitamin C in the training period and calcium intake in the competition period was insufficient. Other studies have shown similar findings regarding inadequate carbohydrate intake, which is also in line with other nutrient ratios as well as showing vitamin D and E deficiencies.
In the holistic and interdisciplinary sports training approach, body composition primarily reflects the nutritional status of athletes . Monitoring body composition therefore makes it possible to evaluate the effectiveness of the nutritional and training interventions undertaken. The deliberate manipulation of body composition in different periods of training macrocycles allows, among other things, to support physical performance, meet the physical demands of a given sport, and meet significant exercise loads. Elite endurance athletes are typically lean and have relatively low body mass due to the genetic factors that predisposed them to be successful in their sport, as well as the modifying effects of
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Maughan R.J., Burke L.M., Dvorak J., Larson-Meyer D.E., Peeling P., Phillips S.M., Engebretsen L. IOC Consensus Statement: Dietary Supplements and the High-Performance Athlete. Br. J. Sports Med. 2018;52:439–455.
Do Triathletes Periodize Their Diet and Do Their Mineral Content, Body Composition and Aerobic Capacity Change during Training and Competition Periods? Krzysztof Durkalec-Michalski, Natalia Glowka, Paulina M Nowaczyk, Anna Laszczak, Anna Gogojewicz, Joanna Suliburska; Nutrients. 2022 Dec 20;15(1):6.
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