The above statements recommending diets high in sugars and fats, may be in contradiction with Heart healthy diets advice aiming to diminish the intake of certain types of nutrients such a saturated fats, MUFAtrans fatty acids and cholesterol; and at the same time to increase the intake of Calcium, Potassium and Magnesium.

Cycling is both intensive and endurance exercise. The cyclist tours (France, Italy, Spain) composed of multiple stages are, may be, one of the more demanding sports, in terms of physiological and psychological requirements. The group of sportsmen is one of the most motivated to follow a correct diet; but for a long time it has been one of the groups that commit the greater errors, and believe in myths with respect to which it is a correct feeding.

Recent longitudinal studies (Women heath initiative, february 2006),⁴ seem to demonstrate that a dietary intervention that reduced total fat intake and increased intakes of vegetables, fruits, and grains did not significantly reduce the risk of CHD, stroke, or CVD; in postmenopausal women and achieved only modest effects on CVD risk factors.

But there are already some concerns about the validity of the conclusions raised in that Women heath initiative of february 2006. It seems that the intervention did not test current dietary guidelines, which focus less ontotal fat intake, and more on saturated fats, cholesterol, sodium, and weight maintenance. Dietary changes have been shown to improve CVD risk-factor profiles, although only when part of comprehensive lifestyle changes (see Journal Watch Cardiology Mar 2, 2001). Still, Women heath initiative CVD outcomes data on dietary interventions are not yet firm. Non-pharmacological approaches to blood-pressure control tend not to get the attention they deserve. One effective strategy is the Dietary Approaches to Stop Hypertension (DASH) diet, which emphasizes fruits, vegetables, and low-fat dairy products and is low in saturated and total fat (see JWC Jun 1997, p. 47, accession number 970505002, and N Engl J Med 1997; 336:1117). Reducing the amount of sodium chloride in typical diets also can lower Blood pressure (BP).⁵

Moreover, although there is new interest in the recovery of intramuscular triglyceride stores between training sessions, there is no evidence that diets which are high in fat and restricted in carbohydrate, enhance training.⁶

Given that reducing the amount of sodium chloride in typical diets (as recommended by DASH), may not be practical for many people, it is as well recommended to increase the intake of Potassium, Calcium and Magnesium to achieve an significant reduction of the BP.⁷

We have considered interesting to evaluate the intake by young cyclists, of the nutrients mentioned above; which may in the long term, be associated with risk of hypertension, atherosclerosis, dyslipidemias, and in general with cardiovascular diseases (CVD). The diet has been evaluated at the beginning of the cyclist season (another evaluation will be done at the end of the sport season, to determine the evolution in the considered parameters. Education in healthy and comprehensive lifestyle is essential for the prevention of CVD and the cheapest way to contribute to the people heath.

Methods

Thirty four young cyclists pertaining to the junior team (of 15 to 17 years) and to the Sub23 team (of 18 to 23 years). (http://www.echozas.com/), have participated in the nutritional study.

The cyclists have a regular program of training with technical Directors and trainers; the cyclist were training about six days a week. Along the year they participate in about 12 competitions in the community of Madrid (Spain) and other six Spanish national competitions. They run more than 25,000 km per year.

The nutritional and psychological evaluations are mandatory for the Juniors team; and optional for the Sub-23 team. All cyclists have made a medical examination to participate in the cycling club. They combine their studies with practices of cycling, and their goal is to become professional cyclists.

All are healthy, without disease. They have signed an informed voluntary consent, together with their parents or tutors, if they are under 18 years of age.

Antropometric data and energy requirement

The information required for the evaluation, is provided by cyclists in the "Questionnaire of nutritional habits and physical activity" such as anthropometric data, as well as the amount and intensity of the physica activity that every individual cyclist make.

The Body fat mass (FM) was assessed by bio-impedance measurements, INBODY520 body fat analyzer. Other methods, like skin folds thickness have been used but only with some of the cyclists, and the errors are of similar level.

The anthropometric results are shown in the table I It presents the average and the standard deviation of several parameters like age, weight, height, and Body Mass Index (BMI), percentage of body fat mass (FM), and physical activity factor.

To calculate the physical activity factor the DIAL program is used. All the details on how to calculate those data are in a precedent article⁸. DIAL uses an equation with the weighted daily activity duration; on the basis of values of WHO.⁹

It appears that the Average of intake of Calories (means ± sd = 3,842 ± 615 kcal./d) by the cyclist teams are, slightly lower than the energy required by them according to their activity factor (means ± sd = 4,122 ± 413 kcal./d). The activity factor is higher during the cyclist season, but the nutritional lifestyle remains unchanged, therefore the body fat of the cyclists goes from 15% ± 2 down to about 7% along the sport season.

The intake of macronutrients in their diets, is presented in table II.

Statistical method

The results are expressed in MEANS ± SD. To determine the statistical significance, independent sample t-tests were used to evaluate differences between groups of the same team. Values of p < 0.05 are considered statistically significant.

Linear correlation method has been used to analyse possible associations between nutritional variables and sport achievement variables (using Microsoft Excel).

Informatic tools

PC informatics tools of the Department of Nutrición and Bromatología I of the Faculty of Pharmacy UCM. Madrid (Spain), have been used.

The DIAL program, using a Table with the composition of foods,¹⁰ calculates the energy consumed and the Nutrients (macro nutrients, minerals and vitamins) contained in the daily food ingestion. The information of the ingested food is extracted from the "Questionnaires of Record of food consumption of 7 consecutive days.

In addition the DIAL program uses equations to calculate the energy required, based on the anthropometric data and the hours of physical activity (total energy spent is equal to Resting energy multiplied by the physical activity factor). The serving sizes are based on information provided by the University of Leon, Spain.¹¹

The Microsoft Excel and SIGMA 2.0 programs have been used for the statistical analysis, statistical significance and linear correlation.¹²

Evaluation of the index of quality of the diet (ICD)

Every cyclist participating in the study fill up several questionnaires:

• Questionnaire of nutritional habits and physical activity: where it is recorded the frequency of intake of different groups of foods, some anthropometric data, as well as the amount and intensity of the physical activity performed by the cyclist.

• Questionnaire of Record of food consumption during of 7 consecutive days. This record list all the foods and drinks ingested and its quantities; including supplements, appetizers and snacks; Other useful information are as well included, such as lunch start/end time, the place where they eat, etc.

The Questionnaires data are input into the DIAL program, which after processing it outputs a Result Report detailing the Energy intake, nutrient and the Quality of the Diet, the later based on the recommendations applicable to the studied population group.¹⁰ The results of the cyclist nutritional evaluation are used to determine the diet unbalances; which in the present study have been compared with the data of the Spanish young population of the enKid study.¹³

The index of quality of the Diet (ICD), allows to classify the Diets as, poor diet (< 50 points), diet which needs to be improved (51-80 points), and excellent diet (80-100 points).¹⁴

The ICD is calculated analysing the variety and quantity of groups of food consumed by comparison with the recommendations (CRD). The CRD are determined taking into account the anthropometric data and the energy requirements of the cyclist.¹

Ten criteria are evaluated corresponding to groups of food in the food pyramid. Each criteria may have from 0 till 10 points. The ICD evaluation therefore has a range from 0 till 100 points.

The intake of different groups of foods by the cyclist team is shown in the table III.

Note: the serving sizes are based on information provided by the Univesity of Leon, Spain.¹¹

The resulting index of quality of the diet of the cyclists teams (as calculated by the DIAL program), expressed as MEANS ± SD; is ICD = 67 ± 11 points over 100 points; which as average it is a good diet, but needs to be improved in some groups of foods.

The cyclists of the present study consumes as average excessive quantities of meat, eggs, cholesterol and sodium. At the same time they consume less quantities of fruits than the recommended ones, The intake of cereals and legumes is slightly under the recommended quantities.

As part of the nutritional intervention, individual diets have recommended to the cyclist to correct those unbalances. Those fat and sodium unbalances may jeopardise their health as they are considered risk factors for hypertension and cardiovascular diseases, in the long term.¹⁵ One published study stated that women who consumed five or more servings of red meat per week also had a significantly increased risk of forearm fracture compared with women who ate red meat less than once per week. Recall of teenage diet did not reveal any increased risk of forearm fracture for women with higher consumption of animal protein or red meat during this earlier period of life.¹⁶

Evaluation of the intake of fats

The intake of different types of fats by the cyclist team is shown in the table IV. The cyclists are very active young people, therefore the intake of calories is about 1.55 times the intake of the homologous Spanish males of the enKid study.¹³ The extra energy needed should be taken from ingestion of higher quantities of carbohydrates, but instead of it the cyclists consume as well proportionally increased quantities of fats (they consume diets with slightly lower density of calories than the general young male population), as it is showed in table IV in the column of the density of nutrients per 1,000 kcal. The intake, by the cyclists, of fats and cholesterol is high, although in less in proportion than the energy. By contrary the intake of PUFA is bellow the recommended value, in a similar way to the homologous young people. The PUFA of long chain omega 3 from fish are involved in the control of hypertension.¹⁷ The intake of fish is bellow the recommended guidelines.

Evaluation of the intake of minerals

According to the table IV the cyclists take 1.87 times more of sodium than the homologous young males. It is recognised that cyclists have increased needs of salt due to losses by transpiration. The American Institute of Medicine¹⁸ recommends the intake of less than 3.8 g/d of salt (1.5 g/d of sodium and 2.3 g/d of chloride) for general people; and the intake 5.8 g/d of salt (2.3 g/d of sodium and 3.8 g/d of chloride) for sportsmen with high losses of liquids (because of sweating). It is recognised that this is a stringent recommendation difficult to follow (the average intake in the USA is 8 g/d; and in Spain is 9 g/d); therefore we have considered as acceptable the intake of less than 4.8 g/d for the cyclists. For potassium, Calcium and Magnesium the official recommendations for young people are more than 4,700 mg/d, 1,300 mg/d, and 400 mg/d respectively, without any increase for sportsmen.

Evaluation of the intake of sodium

The intake of sodium by cyclists exceeds as average the recommended value, as presented in the table V. When we classify the cyclists into two groups according to their intake of sodium; group S (47% of cyclists) take equal/more than 4.8 g/d; and group M (53% of cyclists) take less than 4.8 g/d. The group M has a better quality of the diet (69 ± 11) than the group S (65 ± 10), and the difference of intakes by the groups have statistical significance. The high intake of sodium is, in the long term, a risk factor of hypertension and other diseases.⁷

Evaluation of the intake of potassium

The intake of potassium by cyclists is presented in the table VI. When we classify the cyclists into two groups according to their intake of potassium; group A (66% of cyclists) take equal/more than 4.7 g/d; and group B (44% of cyclists) take less than 4.7 g/d. The group A has a better quality of the diet (70 ± 10) than the group B (63 ± 10), and the difference of intakes by the groups have statistical significance. The low intake of potassium by the group B do not protect them from the high intake of sodium and therefore from hypertension and other diseases.⁷

Evaluation of the intake of calcium

The intake of calcium by cyclists is presented in the table VII. When we classify the cyclists into two groups according to their intake of calcium; group X (71% of cyclists) take equal/more than 1,300 mg/d; and group Y (29% of cyclists) take less than 1,300 mg/d. The group X has a better quality of the diet (68 ± 10) than the group B (64 ± 12), and the difference of intakes by the groups have statistical significance. The low intake of calcium by the group B do not protect them from the high intake of sodium and therefore from hypertension and other diseases.⁷ Additionally the intake of calcium is essential for the construction of bones, from the early stages of life till maturity, therefore the group Y which has deficit in the intake of calcium may, in the long term, have risk of osteoporosis, and periodontal diseases.¹⁹