Nutritional Status of an Elite Flat Water Kayak Paddler
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2021-4272-AJSPO – 24 MAY 2021
1 Nutritional Status of an Elite Flat Water Kayak
2 Paddler
3
4 Background: Sports performance, besides the mental and emotional features
5 of the athlete, results from the intertwined relationship between training
6 load, rest/recovery and nutrition. Nutritional deficits or excesses can be
7 deleterious for sports performance. Objective: To describe the nutritional
8 profile of a highly performing kayaker, analysing the adequacy of nutritional
9 habits for training and competition. Methods: An elite kayaker specialized
10 in flat-water races. World Champion, European Champion and Silver
11 medallist in the London Olympic Games, performed 10-12 workouts per
12 week. The nutritional data were obtained by daily register during seven
13 consecutive days. Results: Daily average intake: Energy, 3174±306 kcal;
14 carbohydrate, 4.4±1.2 g.kg-1.dia-1; protein, 1.9±0.3 g.kg-1.d-1; fat, 1.3 ± 0.2
15 g.kg-1.d-1; cholesterol, 638±218 g; fibres, 23.6 ± 9.2 g. Unbalanced ratio
16 between omega-6/omega-3 fatty acids. While water-soluble vitamins are
17 within the recommendations for athletes, fat-soluble vitamins and beta-
18 carotene are below. All macrominerals respect the Dietary References
19 Intake as well as the trace elements with exception of iodine and
20 molybdenum. Conclusion: The elite kayaker has a caloric intake adequate to
21 the training requirements. However, the relative distribution of the various
22 macronutrients need to be changed by reducing fat intake and increasing
23 carbohydrate intake. The low intake of fat-soluble vitamins and beta-
24 carotene may justify supplementation.
25
26 Keywords: kayaking; nutrition; macronutrients; vitamins; minerals
27
28
29 Introduction
30
31 For almost all sports, training and competition at the highest level is
32 incompatible with energy deficits, mainly energy derived from carbohydrate
33 intake. It was sated that chronic energy deficits in active subjects reduces the
34 size of fast-twitch fibers (Henriksson, 1992), which are important for flat-water
35 elite canoeists. Carbohydrates (CHO) are the most important nutrients for
36 muscle and liver glycogen resynthesis. Glucose uptake and glycogen
37 breakdown increase with increasing exercise intensity (Helge et al., 2007).
38 Sports training at the highest level, presupposes very demanding nutritional
39 care to avoid negative overtraining situations that can, not only destroy the
40 competitive potential of the athlete, as well as can affect, in a more or less
41 prolonged way, their health status. Imbalance between training and recovery
42 will have mild to severe negative consequences on performance (Kuipers and
43 Keizer, 1988); however, it urges to introduce nutrition in the equation. Athletes
44 may experience chronic fatigue when carbohydrate intake is insufficient to
45 match energy demands of heavy training (Costill et al., 1988). The seminal
46 study from Bergstrom et al. (1967) showed a good correlation between initial
47 muscle glycogen content and work time until exhaustion at 75% VO2max.
12021-4272-AJSPO – 24 MAY 2021
1 After muscle glycogen depletion, the recovery of long-term work capacity is
2 associated with the carbohydrate content of the diet.
3 Several studies point to nutritional deficits and/or nutritional imbalances,
4 mainly reduced CHO intake, in young male soccer players (Rodrigues Santos
5 & Vasconcelos, 2009), male futsal players from different competitive levels
6 (Silva et al., 2012), male middle-distance runners (Rodrigues Santos et al.,
7 2012), female middle-distance runners (Rodrigues dos Santos et al., 2013). One
8 case study with an elite running marathoner (Rodrigues Santos et al., 2010)
9 showed a nutritional panorama incompatible with the demands of daily
10 training. With nutritional intakes, ranging from 1316 to 3143 kcal/day, it would
11 be difficult to maintain a high-quality workout daily. This elite marathon
12 runner (ranked 4th in the World Championship) had great variations in his
13 competitive performance, which in part could be justified by any nutritional
14 deficiencies induced by the concern, sometimes pathological, of losing body
15 weight.
16 Elite flatwater kayak paddlers commonly train at least twice a day, 6
17 days/week. Training varies between on-water (i.e. in the boat) and out-water
18 (gym, run, bicycle, swimming) sessions. This type of training is very
19 demanding and any nutritional or energy deficit can compromise both the
20 performance and the athlete's health status.
21 With this study, we intended to ascertain the adequacy of the nutritional intake
22 of an elite flatwater kayaker, in the sense of detecting eventual nutritional
23 conditions that may compromise recovery between training efforts and
24 ultimately interfere with the athlete’s sports performance.
25
26
27 Methods
28
29 Subject: this is a case study of an elite kayak paddler, aged 35 years old,
30 with over 15 years of sport experience at the highest international level. He is a
31 former World champion, European champion and silver medallist in the
32 Olympic Games of London. He is currently committed to get position for the
33 Olympic Games in 2021 (Tokyo, Japan). Training characteristics are provided
34 in table 1.
35 Body size: height – 185 cm; body mass – 87 kg (without significant
36 alterations during the microcycle). Body weight was assessed with the same
37 device in the morning in fasting and before the first training session, without
38 clothes except for underwear.
39 The participant was informed about the benefits and risks of participating in the
40 current study prior to signing an informed consent form, which was approved
41 by the ethics board of the local university . Experimental procedures were in
42 accordance with the Helsinki Declaration and ethical principles for medical
43 research involving human subjects (Harriss et al., 2019).
44
45
22021-4272-AJSPO – 24 MAY 2021
1 Table 1. Training characteristics over the microcycle
Day Morning Afternoon
Water. 15 km. 6 x 250m Gym (Strength). 6 exercises x 6
Monday (115/120 spm), rest 5’. RM x 6 sets +
Stretching Abdominals/Lumbars. Stretching
Water. 15 km. 2 x 1000m /
rest 8’ (250m at 85 spm,
500m at 90 spm, 250m at 95 Water. 10 km. Easy pace. 65
Tuesday spm) + 2 x 750 m / rest 8’ spm.
(250m at 115 spm, 250 at 110 Stretching
spm, 250m at 115 spm).
Stretching
Water. 15 km. 8 x 45” (110 Gym (Strength). 6 x 20 reps/rest
spm) 1’15” rest. Recovery 6’. 40”, 55% Maximum Load +
Wednesday
8 x 30” (115 spm), 1’30” rest. Abdominals/Lumbars. 30’
Stretching running. Stretching
Water. 10 km. 6 x 10”/rest
Thursday 1’50”. Maximum pace. Start Rest
stopped. Stretching.
Water. 15 km. 2 x 1000m /
rest 8’ (250m at 85 spm,
500m at 90 spm, 250m at 95 Gym (Strength). 6 exercises x 6
Friday spm) + 2 x 750 m / rest 8’ RM x 5 sets +
(250m at 115/120 spm, 250 at Abdominals/Lumbars. Stretching
110/115 spm, 250m at
115/120 spm). Str
Water. 15 km. 7 x 50” at 105
spm/1’10” rest. Recovery 6’ Water. 8 km. Easy pace (65 spm)
Saturday
+ 7 x 35” at 110 spm / 1’25” + Stretching.
rest. Stretching.
Water. 10 km. Easy pace. (65
Sunday Rest
spm) + Stretching.
2 spm = strokes per minute; RM = repetitions maximum. Note: a specific warming-up preceded
3 every workout.
4
5
6 Nutritional Data Collection
7
8 A record of seven consecutive days of food consumption over a
9 microcycle was assessed. The record was divided as follows: breakfast,
10 morning snack, lunch, afternoon snack and supper. The results are presented in
11 the tables (2-6) include food supplements contributing to the energy intake. A
12 dossier with informative photographs with the standard quantities of the main
13 foods was delivered and the athlete informed of the correct way to fill in the
14 forms according to the quantities consumed. Mean daily food intake was
15 converted to nutrients using ESHA’s Food Processor Nutrition Analysis
16 software (Bazzano et al., 2002). For the consumption of macronutrients, we
17 take as reference the American College of Sports Medicine proposals (ACSM,
32021-4272-AJSPO – 24 MAY 2021
1 2000); for micronutrients we rely on the review criticism of Whiting & Barash
2 (2006) and Murray & Horswill (1998) proposals.
3
4
5 Results
6
7 Table 2 shows that the kayaker has an adequate energy intake, low
8 carbohydrate intake, high intake of cholesterol and reduced intake of dietary
9 fibres.
10
11 Table 2. Mean values (±SD) for energy and macronutrients intake
Indicators Mean ± SD Minimum Maximum
Energy intake (kcal) 3174 ± 306 2722 3631
Energy intake (kcal/kg) 36.0 ± 3.4 31.2 40.8
Protein (g.day-1) 163.4 ± 29.0 121.0 211.0
Protein (%) 20.8 ± 4.3 15.0 25.4
Protein (g.kg-1.dia-1) 1.9 ± 0.3 1.39 2.43
Carbohydrate (g.day-1) 383.4 ± 103.3 260.0 576.0
Carbohydrate (%) 47.8 ± 9.3 38.2 63.5
Carbohydrate (g.kg-1.day-1) 4.4 ± 1.2 2.99 6.62
Fats (%) 31.4 ± 5.2 21.6 36.4
Fats (g.kg-1.dia-1) 1.3 ± 0.2 1.0 1.53
Saturated fats (%) 11.5 ± 2.3 6.4 13.4
Monounsaturated fats (%) 11.9 ± 1.8 8.6 13.9
Polyunsaturated fats (%) 4.8 ± 1.5 3.0 7.4
Cholesterol (mg) 638 ± 218 420 1066
Dietary fibre (g) 23.6 ± 9.2 12.4 40.6
Complex CHO (%) 15. 7 ± 3.6 11.0 20.7
Sugars (%) 20.2 ± 9.2 9.7 36.4
Caffeine (mg) 5.8 ± 5.9 0 13.4
Alcohol (g) 0 0 0
Insoluble fibers (g) 14.1 ± 7.8 2.71 28.0
Soluble fibers (g) 4.0 ± 1.9 0.95 6.94
Water (ml) 1790 ± 544 1245 2665
12
13 From the table 3, it can be seen a high intake of trans fatty acids and an
14 unhealthy ratio omega6: omega3 fatty acids.
15
16 Table 3. Mean values (±SD) for some fatty acids intake
Fatty acids Mean ± SD Minimum Maximum
Omega-3 fatty acids (g) 1.4 ± 0.3 1.09 2.0
Omega-6 fatty acids (g) 11.6 ± 2.9 8.26 16.1
Trans fatty acids (g) 4.5 ± 4.4 0 9.77
Oleic acid (g) 33.6 ± 5.6 27.5 42.9
Arachidonic acid (g) 0.3 ± 0.2 0.09 0.57
17
18 The participant in this study has an adequate intake of hydro-soluble
19 vitamins and a reduced intake of fat-soluble vitamins.
42021-4272-AJSPO – 24 MAY 2021
1 Table 4. Mean values (±SD) for vitamin intake
Recommendations for athletes
Vitamins Mean ± SD
(Murray and Horswill, 1998)
Thiamine (mg) 3.4 ± 0.9 1.5 mg
Riboflavin (mg) 2.7 ± 0.4 1.7 – 1.8 mg
Niacin (mg) 35.7 ± 8.4 19 – 20 mg
Vitamin B6 (mg) 3.2 ± 0.8 2 mg
Vitamin B12 (µg) 7.0 ± 1.2 2 µg
Folate (µg) 351.1 ± 138.9 200 µg
Pantothenic acid (mg) 7.5 ± 1.3 4 – 7 mg
Vitamin A (µg) 388 ± 135 1000 µg
Vitamin A Carotene (µg) 165 ± 110 6000 µg
Vitamin C (mg) 302 ± 224 60 mg
Vitamin D (µg) 3.1 ± 0.9 10 µg
Vitamin E (mg ET) 7.9 ± 2.3 10 mg
Vitamin K (µg) 36.4 ± 27.3 70 – 140 µg
2
3 Table 5 shows that macrominerals intakes are all within or exceed the
4 international references for athletes.
5
6 Table 5. Mean values (±SD) for macrominerals intake
Macrominerals Mean ± SD DRI*
Calcium (mg) 848.1 ± 1 800 - 1200 mg
Magnesium (mg) 431.4 ± 76.8 350 mg
Phosphorus (mg) 1772 ± 140 800 - 1200 mg
Potassium (mg) 4523 ± 1309 1875 – 5625 mg
Sodium (mg) 3089 ± 1142 1100 – 3300 mg
Chloride (mg) 856 ± 606 2300 mg
7 *Dietary reference intakes. Washington, DC, 1997, 1998, 2000 and 2002.
8 All trace minerals with exception of iodine and molybdenum are within the nutritional
9 references.
10
11 Table 6. Mean values (±SD) for trace elements intake
Trace Minerals Mean ± SD DRI *
Copper (g) 1.8 ± 0.5 0.9 g
Iron (mg) 21.1 ± 4.4 8 mg
Manganese (mg) 3.2 ± 1.0 2.3 mg
Selenium (µg) 179.3 ± 22.7 55 µg
Zinc (mg) 19.9 ± 5-7 11 mg
Boron (mg) 3.4 ± 1.7 NA
Iodine (µg) 66.5 ± 8.1 150 µg
Molybdenum (µg) 12.6 ± 9.9 45 µg
12 *Dietary reference intakes. Washington, DC, 1997, 1998, 2000 and 2002.
13
52021-4272-AJSPO – 24 MAY 2021
1 Discussion
2
3 The nutritional needs for elite athletes must be considered individually and
4 adjusted to the requirements of training and competition. Elite kayakers usually
5 practice twice a day with each workout lasting between 1.5 and 2 hours. This
6 type of training is very demanding at several levels, with the binomial
7 recovery/nutrition being of fundamental importance. Energy and carbohydrate
8 and protein needs must be met during exhaustive training to maintain body
9 weight, resynthesize muscle glycogen, and provide sufficient protein to build
10 and repair muscle tissue. The average value of the daily energy supply for our
11 kayaker is 36.0 ± 3.4 Kcal/kg/day that is in line with the values found for
12 strength-type sports (e.g. bodybuilding, judo, and weight lifting) but clearly
13 below the values found for long-lasting endurance sports (e.g. triathlon,
14 cycling, marathon) (Erp-Baart et al., 1989a). The first line of analysis concerns
15 the verification of the combined effect of training and nutrition on body weight
16 variations. During the study, the athlete's body weight remained stable with
17 slight daily variations not exceeding 100 g. These results are an index of the
18 adequacy of caloric intake to caloric expenditure. Intense and systematic
19 training develops superior energy efficiency (De Feo et al., 2003) increasing
20 the ability to support the same training load with a lower expenditure of
21 energy. It seems that some athletes are able to adjust their energy intake to the
22 volume and intensity of training, hence the variations seen in the caloric intake
23 of many elite athletes (Rodrigues Santos et al., 2010; 2102; 2013). While
24 energy intake appears to match caloric expenditure, the relative contribution of
25 the various macronutrients does not seem to be the most adequate. The low
26 values of CHO ingestion, either as a percentage of total energy intake or when
27 relative to body weight, are very low in relation to the recommendations for
28 athletes. When training is intensified, low CHO intake reduces muscle
29 glycogen concentration and increases muscular fatigue (Costill et al., 1988)
30 reducing the ability to cope with exhaustive loads. Recommendations for CHO
31 intake ranges of 5 to 7 g/kg/day for general training. For endurance athletes 7
32 to 10 g/kg/day of CHO are suggested (Burke et al., 2001). We can hypothesize
33 that at least in some workouts this kayaker has a suboptimal level of glycogen
34 stores with deleterious effect on training intensity and mood for hard training.
35 It is important to highlight that the brain has an increased need for CHO during
36 recovery from strenuous exercise (Nybo et al., 2003). However, as the protein
37 intake is high, it can contribute not only to tissue repair but also to glycogen
38 synthesis through gluconeogenesis. For 50 g of glucose produced, 34-40 g
39 come from glycogenesis, 8-14 g from protein deamination and 2-3 g from
40 glycerol (Fromentin et al., 2013). Protein intake in the range of 1.3 – 1.8 g.kg-
1
41 .day-1 maximize muscle protein synthesis in athletes (Phillips & Van Loon,
42 2011). The average values of protein ingested in this study seem be adequate
43 not only for muscle repair and accretion as well as for energetic purposes. Fat
44 intake is high although within dietary references for athletes (Rodriguez et al.,
45 2009); the problem is that the high fat intake is made at the expense of CHO.
46 Regarding the type of fats, there is an average high intake of saturated fats
62021-4272-AJSPO – 24 MAY 2021
1 (SFs) and a reduced intake of polyunsaturated fats (PUFs). Intake of
2 monounsaturated fats (MUFs) is adequate and reflects the Mediterranean
3 dietary pattern. What means a high intake of SFs to a highly active athlete?
4 Epidemiological studies suggest that reducing dietary SFs reduces the risk of
5 cardiovascular events and myocardial infarction (Hooper et al., 2015). In our
6 view, epidemiological approaches lose consistency in the high-performance
7 sports field. The focus should be on the effects of the imbalance between the
8 intake of SFs in relation to the intake of PUFs. Reduced intake of PUFs namely
9 the two essential fatty acids (EFAs), alpha-linolenic acid (ω3) and linoleic acid
10 (ω6) can negatively affect the production of prostaglandins, which help
11 regulate blood viscosity, inflammatory processes, blood cholesterol and fat
12 levels, and water balance (Oesterling et al., 1972). It is well known that
13 exhaustive exercise is a remarkable producer of inflammation outbreaks. Since
14 the body does not synthesize EFAs, they must be provided by the food. The
15 Western diets, namely Mediterranean diet, provide a high amount of ω6 fatty
16 acids. This nutritional condition favors the formation of eicosanoids that arise
17 from the oxidation of arachidonic acid and related PUFs by cyclooxygenase,
18 lipoxygenase and cytochrome P450 enzymes and via non-enzymatic free
19 radical mechanisms (Dennis & Norris, 2015). Eicosanoids are related to the
20 pro-inflammatory response. Non-steroid anti-inflammatory drugs, prostanoids
21 and dietetic fish oil ω3 fatty acid supplementation control the action of
22 eicosanoids (Norris & Dennis, 2012). Therefore, the high intake of ω6 fatty
23 acids to the detriment of ω3 can accentuate the inflammatory processes
24 naturally induced by exercise and delay recovery between efforts. Although
25 there is no consensus among nutritionists, a daily intake of 9 g of ω6 and 6 g of
26 ω3 is recommended, which gives a ratio of 1.5-1.0 (Erasmus, 1993). In this
27 study, the average intake of ω6 exceeds the recommendations while those of
28 ω3 is far below the recommendations. The ratio ω6:ω3, circa 8:1, can hinder
29 the buffering of inflammatory processes. Other studies present a similar
30 scenario (Rodrigues dos Santos et al., 2010; 2012; 2013). In order to rebalance
31 this particular aspect of the diet, the athlete must increase the consumption of
32 cold water fish such as salmon, mackerel and sardines, however there is no
33 evidence of the relationship between the consumption of food rich in ω3 and
34 sports performance. Huffman et al. (2004) showed that supplementation with
35 ω3 fatty acids did not improve endurance performance during a maximal bout
36 of exercise. A more balanced diet is desirable since nutrition does not make a
37 champion but can prevent it from being. Our subject has a high average
38 consumption of trans fatty acids. These fatty acids, processed or natural
39 occurring, are related to several diseases (Souza et al., 2015). In an athlete with
40 a very high level of training, the clinical perspective does not apply, however,
41 the intake of foods rich in trans fatty acids should be reduced as much as
42 possible and not exceed 2 g/100g fat per day (Leth et al., 2006). Cholesterol is
43 mainly synthesized from dietary saturated fats and there is no scientific
44 evidences to validate the hypothesis that dietary cholesterol increases blood
45 cholesterol. Therefore, previous recommendations from the American Heart
46 Association restricting dietary cholesterol to 300 mg/day were removed
72021-4272-AJSPO – 24 MAY 2021
1 (Soliman, 2018). Our kayaker has a high uptake of dietary cholesterol directed
2 related to the high uptake of SFs. At first glance, this athlete's lipid outlook
3 could be worrying - high intake of SFs, dietary cholesterol, and total fat.
4 However, blood tests done regularly by this kayaker point to blood values of
5 triglycerides and cholesterol within normal laboratory values. Exhaustive daily
6 training is the best way to cancel out the possible deleterious effects of a high
7 fat diet. The recommendations for the consumption of dietary fibers is 20 to 35
8 g per day (Escudero & Gonzalez, 2006), that is, twice the consumption of our
9 athlete. For the good functioning of the digestive system, it is advisable to
10 reduce the simple sugars, processed foods and increase the foods rich in fiber.
11 This athlete does not drink any alcohol. This is a healthy behavior because
12 chronic alcohol consumption is related to unfavorable changes in the immune
13 system, the clotting process and brain integrity (El-Sayed et al., 2005).
14 Caffeine intake, between 0 and 13.4 mg, is not significant because a single cup
15 of espresso takes about 60 ml of coffee, and contains about 126 mg of caffeine.
16 After Erp-Baart et al. (1989b), when energy intake ranges between 2388
17 and 4776 kcal/day vitamin and mineral intake is sufficient. Our data only
18 partially confirm this statement. Although caloric intake is adequate, the intake
19 of water-soluble vitamins exceeds the recommendations while the intake of fat-
20 soluble vitamins is below the recommendations for athletes (Murray &
21 Horswill, 1998). Can low fat-soluble vitamin intake be problematic for this
22 athlete? The answer seems be negative. Photochemical processes from the
23 cholesterol can synthesize vitamin D. Adequate amounts of vitamin E are
24 necessary to prevent peroxidation of tissue PUFs. Vitamin E deficiency is
25 extremely rare in humans and it is unlikely caused by dietetic limitations
26 (Kemnic & Coleman, 2021). The intake of vitamin E observed in our athlete,
27 below the recommendations, is in line with the low intake of polyunsaturated
28 fatty acids. Low PUFs intake reduce the needs of vitamin E. An intake of 0.6
29 mg alpha-tocopherol equivalents per gram linoleic acid is generally seen as
30 adequate for human adults (Valk & Hornstra, 2000). Our values, 7.9±2.3 mg of
31 vitamin E for 10.5±3.0 g of linoleic acid, gives a surplus of antioxidant
32 protection. Vitamin K1 (phylloquinone) derives from green leafy vegetables
33 while vitamin K2 (menaquinone) is synthesized in the gut from the bacteria.
34 Even in a situation of low dietary intake, synthesis in the ileum from the
35 bacteria seems sufficient to respond to the body's demands (Conly & Stein,
36 1992). However, to normalize the intake of phylloquinone, the athlete should
37 be advised to eat more green leafy vegetables such as parsley, spinach, broccoli
38 and kale. These foods benefit bone metabolism and the coagulation system
39 (Sim et al., 2020).
40 The low values of vitamin A and beta-carotene intake observed in this
41 athlete should be corrected to improve immune response to exercise,
42 maintenance of epithelial cells integrity and protection against oxidative free
43 radicals attack (Bar-El Dadon & Reifen, 2017). Reactive oxygen species (ROS)
44 and reactive nitrogen species (RNS) produce both deleterious and beneficial
45 effects. Overproduction of ROS (arising either from mitochondrial electron-
46 transport chain or from excessive stimulation of NADPH) results in oxidative
82021-4272-AJSPO – 24 MAY 2021
1 stress (Valko et al., 2007). During training, kayakers dramatically increase their
2 oxygen consumption. Probably this causes an increase in free radicals
3 production, which are supposed to have a plethora of deleterious effects. Some
4 diseases, like cancer and cardiovascular diseases are associated with increased
5 ROS production (Halliwell, 2012). These highly reactive molecular species are
6 capable to damage some important macromolecules as DNA, proteins,
7 carbohydrates, and lipids. The first line of defense against oxidative stress is
8 enzymatic – superoxide dismutase (SOD), catalase (CAT), and glutathione
9 peroxidase/glutathione reductase (GPX) (Ighodaro & Akinloye, 2018). We can
10 consider exogenous antioxidants (tocopherol, ascorbate, ß-carotenes,
11 flavonoids) provided by the diet as the second line of defense against oxidative
12 stress. It is common practice in sport to ingest high amounts of anti-oxidant
13 substances to combat oxidative stress induced by prolonged and / or intense
14 exercise. The effects of these practices are dubious. For instance, many
15 polyphenols, such as the flavonoids, have remarkable antioxidant activity in
16 vitro but there are few, if any, compelling data that polyphenols exert
17 antioxidant effects in vivo (Halliwell et al., 2005). Some authors highlight the
18 beneficial effects of ROS. ROS have become increasingly recognized to
19 mediate some adaptive responses in skeletal muscle induced by exercise.
20 Therefore, exercise-associated increases in ROS are likely to involve redox-
21 sensitive signaling effects rather than oxidative damage (Webb et al., 2017).
22 Regardless of the benefits or harms of ROS, an athlete should enrich his diet
23 with fruits, grains and vegetables that in addition to the antioxidant fight have
24 other benefits for the individual's health.
25 With the exception of chloride, all macrominerals are within or exceed the
26 DRI. The low mean chloride intake in our subject has no clinical significance
27 because, in healthy individuals, NaCl homeostasis is fine-tuned in renal
28 collecting ducts where Cl urinary excretion is balanced with dietary salt intake
29 (Rajagopal & Wallace, 2015). These low values of Cl are in line with other
30 studies with elite athletes (Siqueira & Rodrigues dos Santos, 2004; Rodrigues
31 dos Santos et al., 2010).
32 With the exception of iodine and molybdenum, all trace minerals are
33 within the references. Selenium, manganese, cooper and zinc the principal
34 minerals linked to antioxidant defense respect the recommendations. To avoid
35 persistent iodine deficits the athlete must increase the consumption of fish.
36 Low average values of molybdenum can affect the formation of the enzyme
37 xanthine oxidase, which is fundamental to transform xanthine into uric acid
38 (Rajagopalan, 1988). To correct this nutritional deficit the athlete must increase
39 the consumption of milk, legumes and whole grains. These foods are excellent
40 sources for almost all macro- and macrominerals.
41
42
43 Conclusion
44
45 The elite kayaker in this study has a nutritional intake that needs some
46 corrections. The absence of significant fluctuations in body weight points to
92021-4272-AJSPO – 24 MAY 2021
1 adequate caloric intake. While protein intake matches well the needs for
2 muscle repair and accretion, low carbohydrate intake does not respect the
3 recommendations for strength-endurance athletes and can put some problems
4 in relation to the best energy conditions during high intensity workouts.
5 Therefore, this athlete must reduce the fat intake and increase the supply of
6 CHO. Despite the high intake of fats, the supply of some fat-soluble vitamins –
7 A, D, E, and K does not met the recommendations. Although the intake of
8 beta-carotene is low, the adequate intake of micro minerals connected with the
9 antioxidant defense points to the potentiation of endogenous mechanisms to
10 fight oxidative stress. Based on the data in this study, the increase in the supply
11 of CHO and some vitamins and minerals is justified, either through
12 supplementation or through enrichment of the diet with specific foods that
13 cover the deficits found.
14 Dietary guidelines for health focus on unprocessed foods, fruits and
15 vegetables, plan-based fats and proteins, legumes, whole grains and nuts.
16 Emphasis should be placed on monounsaturated fats, such as olive oil,
17 avocados, and nuts, and omega-3 fatty acids. Respecting energy needs, a diet
18 with this profile is also adequate for elite athletes specialized in strength-
19 endurance sports like our kayaker.
20
21
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