Ramutis Kairaitis

Dr. Ramutis Kairaitis

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Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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TLTomas Liubertas
Tomas Liubertas
RKRamutis Kairaitis
Ramutis Kairaitis
LSLoreta Stasiulė
Loreta Stasiulė
SCSandrija Capkauskiene
Sandrija Capkauskiene
ASArvydas STASIULIS
Arvydas STASIULIS
DUDalia Urbonaviciene
Dalia Urbonaviciene
Recent evidence indicates that elevating plasma nitrites through dietary nitrates (NO3−) supplementation is associated with enhanced muscle efficiency, fatigue resistance and performance. Beetroot (in various forms) is the dominant source of dietary NO3− primarily due to its vast availability and the simple form of preparation suitable for final consumption. After a few years of research and experimentation, our scientific team identified alternative source rich with dietary NO3− as possible nitric oxide precursor, amaranth (Amaranthus hypochondriacus) with a standardized concentration 9–11% of NO3−. This study aimed to evaluate the effect of single-dose (±400 mg of dietary NO3−) and long-term (6 days) supplementation of amaranth concentrate derived dietary NO3− on aerobic capacity in physically active young people. We conducted a randomized, double-blind, placebo-controlled human study. Thirteen healthy and physically active young male participants were randomized into experimental and placebo groups. The aerobic capacity was tested during increasing cycling exercise (ICE) with pulmonary gas exchange recording and analysis. The peak power of the ICE, the maximum oxygen consumption and the first ventilatory threshold were significantly increased after long-term consumption of dietary amaranth (from 4.44 ± 0.50 to 4.55 ± 0.43 W/kg; from 37.7 ± 2.7 to 41.2 ± 5.4 mL/kg/min and from 178.6 ± 30.3 to 188.6 ± 35.2 W, p < 0.05; respectively) in experimental group. Long-term (6 days) use of dietary NO3− from amaranth may improve the aerobic capacity during ICE in young physically active male persons. It can be recommended as the nutritional supplement during last week of preparation for competition in endurance events.

12 July 2025 in Nutrients
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Journal Article
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RKRamutis Kairaitis
Ramutis Kairaitis
PMPetras Minderis
Petras Minderis
ILInga Lukonaitienė
Inga Lukonaitienė
GMGediminas Mamkus
Gediminas Mamkus
TVTomas Venckunas
Tomas Venckunas
SKSigitas Kamandulis
Sigitas Kamandulis
Background: The Fit-Model in bodybuilding is a relatively new category designed for women seeking a balanced physique, avoiding excessive muscularity and extreme leanness. This study examined the dietary strategies, body composition changes, and plasma leptin fluctuations of Fit-Model athletes during a seven-week pre-competition phase. Methods: Twelve females (age: 27.6 ± 4.4 years, body mass: 60.0 ± 6.2 kg) preparing for a national championship were monitored for energy and macronutrient intakes, total, lean, and fat mass, plasma leptin levels, and menstrual cycle characteristics. The five highest-ranked athletes were selected to compete at the world championship, allowing for comparisons between national and international athletes. Results: Low carbohydrate intake was reported, and total energy intake decreased from 1700 to 1520 kcal/day approaching the contest day. Athletes experienced an average body mass loss of 4.2 kg, with no clear relationship between final weight or fat mass and competitive success. Plasma leptin levels were markedly low during all 7 weeks of preparation with a further decline before the contest, but did not correlate with either changes in body composition and weight or energy or macronutrient intakes. Menstrual cycle disturbances were prevalent, with only two athletes maintaining regular cycles by the end of the preparation. Conclusions: Fit-Model athletes undergo a considerable decline in body weight and fat mass during the final weeks before the contest, yet these changes do not appear to be decisive for performance outcomes. Persistently low leptin levels and menstrual irregularities call for strategies that balance physique optimization with endocrine health to support both the performance and well-being of athletes.

1 September 2024
Verified
Journal Article
Open access
RKRamutis Kairaitis
Ramutis Kairaitis
GMGediminas Mamkus
Gediminas Mamkus
HDHans Degens
Hans Degens
SKSigitas Kamandulis
Sigitas Kamandulis
Objectives: To compare the pre-competition nutrition practices of Lithuanian elite international-level (IL) and nationallevel (NL) bodybuilders. Methods: Sixteen male bodybuilders (n=8 per group) were enrolled. The IL group comprised individuals achieving 1st to 4th place in the World and European Championships organized by the IFBB, whereas the NL group ranked between 1st and 6th place in the national championships. Body mass and diet data were obtained via a questionnaire. A repeated-measures ANOVA was performed using time as a within factor and group as a between factor. Results: Both groups experienced a reduction in body mass during the pre-competition phase (p<0.001), which was slower in the IL than in the NL group (p=0.048). Both groups exhibited a reduction in caloric (p<0.001), carbohydrate (p<0.001), and fat (p=0.006) intake relative to body mass, but not in protein intake. Nevertheless, the IL group had a higher intake of calories (p=0.015), protein (p<0.001), but not carbohydrates relative to body mass vs. the NL group. Conclusions: The Lithuanian IL and NL bodybuilders both reduced calories by cutting fat and carbohydrates during pre-competition. The IL group maintained higher calorie and protein intake, resulting in similar body mass loss but at a slower rate than the NL group.