Baltymams būdingas dinamiškumas – nuolatinis savo sudėties atnaujinimas. Dalyvaujant organizuotoje fizinėje veikloje, baltymų oksidinimo, skilimo ir sintetinimo procesai organizme greitėja, todėl sportininkų organizmo maisto baltymų poreikis išauga. Rekomenduojamas vartojamų baltymų kiekis sportininkams svyruoja nuo 1,2 iki 2,2 g / kg kūno masės per dieną. Tačiau vartojimui rekomenduojamos baltymų kiekio ribos yra labai plačios. Tyrimo tikslas – racionalizuoti maisto baltymų vartojimo rekomendacijas sportininkams tokiu lygiu, kad jomis vadovaujantis būtų optimaliai užtikrintos anabolinės reakcijos organizme. Buvo atliktas kiekybinis vienmomentis skerspjūvio tyrimas, kurio metu, parengiamuoju varžyboms laikotarpiu, buvo ištirti vidutiniškai 6 kartus per savaitę, 117,7 ± 32,1 min. per dieną besitreniruojantys profesionalūs sportininkai (n = 323). Vartojamų maisto baltymų kiekis nustatytas pritaikius 24 valandų trijų dienų iš eilės faktinės mitybos apklausos metodą. Azoto pusiausvyra organizme apskaičiuota netiesioginiu būdu pritaikant specialias lygtis. Tyrimo duomenimis, optimalus baltymų kiekis, sudarantis 1,4–1,7 g/kg kūno masės per dieną, profesionaliems sportininkams yra pakankamas, norint organizme užtikrinti teigiamą azoto pusiausvyrą. Sportininkams, siekiantiems stimuliuoti anabolines reakcijas organizme, reikalingas padidinto baltymų kiekio vartojimas, kai dienos baltymų dozė sudaro 1,8–2,2 g/kg kūno masės. Baltymų vartojimas 2,3–3,1 g/kg kūno masės per dieną dozėmis gali būti pateisinamas ir rekomenduojamas išskirtinai individualiais atvejais, kai sportininkai treniruotės procese kryptingai didina lieknąją kūno masę. Prioriteto tvarka mokslo darbo autoriai pirmenybę teikia tvariai mitybos ir sportinės veiklos rezultatų praktikai. Pirmą kartą Lietuvoje publikuota aiški baltymų vartojimo schema, atsižvelgiant į sportininkų organizmo azoto pusiausvyros rodiklius. Siekiant racionalizuoti anabolines reakcijas didelio meistriškumo sportininkų organizme, šio tyrimo autoriai sukūrė normatyvinę rekomenduojamus baltymų kiekius klasifikuojančią lentelę. Šio tyrimo rezultatai ir rekomendacijos pritaikomos tarp sportininkų ir sportuotojų, norinčių strategiškai valdyti savo mitybos įpročius ir baltymų vartojimą.

Aiming to make the nutrition of Lithuanian Olympic athlete’s representing endurance sports individual and optimal, the amount of dietary fat should not be strictly limited. Athletes’ nutrition with sufficient amount of fat determines that fat as an energy source substrate are utilized more effectively for energy production during prolonged endurance training. Furthermore, any adaptations of athletes organism leading to an increased capacity to utilize fatty acids for adenosintriphosphate resynthesis during very high intensity and (or) prolonged endurance physical training determines lesser utilization of endogenous carbohydrates which is related to the endogenous carbohydrates sparing and more effective utilization of muscle glycogen. That purposed the aim of our work to ascertain and estimate the influence of factual diet to energy expenditures during ultra endurance training of Lithuanian Olympic athlete’s representing cycling, long distance running and long distance walking sports. The results of research have shown that dietary carbohydrates and fat in high performance Lithuanian Olympic athlete’s representing endurance sports food rations are unbalanced. However, identified dietary carbohydrate and fat amounts are sufficient to ensure the physiological needs for fat and carbohydrates of endurance-trained high performance Lithuanian Olympic athlete’s organism. It was established that the potential of adaptation of high performance Lithuanian Olympic athletes’ representing endurance sports are not equal. More effective utilization of fat as a source substrate for energy production during low (30 % VO2 max ) intensity and moderate (50 – 60 % VO2 max ) intensity endurance training is associated to lower carbohydrate oxidation rate which is related to more effective utilization of carbohydrates during very intensive and (or) prolonged endurance training.[...]

Athletes and their coaches must pay special attention to nutritional care as an integral part of a proper diet for optimal physical development of athletes and achieving optimal results. Special exception in sports science is given to endurance athletes. Particular attention is paid to endurance-trained female athletes who are often attributed to the unbalanced nutritional risk group. These data led to the objective: to assess the nutritional status and body composition of Lithuanian high-performance cyclists by gender. In 2012, during the general preparation have been investigated and evaluated the diet and body composition of Lithuanian high-performance cyclists (n = 50). The results showed that the optimal physical development of male athletes and moderate physical development of female athletes is determined by Lithuanian elite cyclist’s diet. Regardless of gender, athlete’s nutrition does not meet the requirements. This is confirmed by the data that protein intake of cyclists does not meet the guidelines, including the fact that carbohydrate, polyunsaturated fatty acids, vitamin A and vitamin D, magnesium and manganese intake is lower than recommended. Male athletes consume too much fat, saturated fatty acids and cholesterol, while female athletes are assigned to the risk group of an unbalanced nutrition. Energy intake of female athletes is less then energy expenditure. Women’s diet is critically low in carbohydrates, protein, essential amino acids such as valine, leucine, isoleucine, methionine, lysine, phenylalanine, omega-3 fatty acids and omega-6 fatty acids, vitamin A, vitamin D, vitamin B12, folic acid, potassium, calcium, phosphorus, iron, copper and zinc. In conclusion: cyclist’s nutrition must be optimized, individualized and adjusted according to the athletes’ gender. Based on the scientific basis, cyclists are highly recommended for the supplementation with carbohydrate, essential fatty acids (omega-3 fatty acids and omega-6 fatty acids), vitamins and minerals.

Physical development of high-performance winter sports athletes must be optimal, and with proper diets athletes must ensure an increased their body’s needs for essential nutrients. Only a scientific evaluation of the athletes’ nutrition status provides the opportunity to adjust, optimize and personalize their diets properly. The aim of the present research was to assess nutrition status (3-day food records), physical development for high-performance Lithuanian skiers and biathletes. Research on the athletes nutrition status and physical development was carried out in the preparatory competition period in 2013. The sample included skiers (n = 14) and biathletes (n = 20). The results showed that nutrition profile of Lithuanian elite skiers and biathletes determines an optimal physical development of male athletes and a moderate physical development of female athletes. Nevertheless, nutrition status of skiers and biathletes does not meet the requirements. This is confirmed by the data that protein intake of athletes does not meet the guidelines, their diets lack carbohydrates and there is too much fat. It was found that the athletes’ nutrition status depends on gender. Male athletes’ diets do not contain enough carbohydrates, polyunsaturated fatty acids (omega-3 fatty acids and omega-6 fatty acids), vitamin D and contain too much protein, fat, saturated fatty acids and cholesterol. On the contrary, the energy intake of food does not cover the energy expenditure of female athletes, their diets lack carbohydrates, protein, non-essential aminoacid phenilalanine, omega-3 fatty acids, vitamins D, A, B1, B2, B12, folic acid and minerals potassium, calcium, phosphorus, iron, copper and zinc. In conclusion the nutrition of high-performance winter sports athletes in Lithuania must be optimized, individualized and adjusted according to the gender. Special attention must be paid to nutritional care of female athletes, which nutrition profile does not meet the requirements and can‘t stimulate maximal adaptation of the body to long-lasting and (or) highintensity physical loads.