Comparison of Neuromuscular Characteristics of Strict Vegetarians and Non-Vegetarians Women and Their Adaptations After 16 Weeks of Strength Training
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 128
- 试验地点
- 1
- 主要终点
- Quadriceps femoris muscle thickness assessed by ultrasonography images
研究概览
简要总结
A strict vegetarian diet includes only foods of plant-based origin and, despite being able to meet the nutritional needs of individuals of different ages, when correctly planned, it commonly offers a lower protein intake than a non-vegetarian diet. Daily protein intake directly influences the turnover of body proteins (synthesis vs. degradation rates), being important for the maintenance of skeletal muscle mass, tissue that performs metabolic functions in the body and enables the performance of tasks of daily living. In addition, the practice of strength training (ST) interferes in muscle mass increasing rates, also exerting an influence in muscle quality, strength and power increase, which are associated with better physical fitness, quality of life and health. To make these increases possible, especially in relation to morphological aspects, a higher protein intake than recommended for the general population is necessary (1.2 to 1.6 g/kg/day), which requires careful dietary planning, especially when the consumption of meat, eggs and dairy products, which are important sources of this nutrient, is excluded. Thus, the present study has two main objectives: to compare the neuromuscular characteristics of strict vegetarians (VE) and non-vegetarians (NV) (Phase 1 - cross-sectional) and the neuromuscular adaptations induced by 16 weeks of ST (Phase 2 - longitudinal).
详细描述
A strict vegetarian diet includes only foods of plant-based origin and, despite being able to meet the nutritional needs of individuals of different ages, when correctly planned, it commonly offers a lower protein intake than a non-vegetarian diet. Daily protein intake directly influences the turnover of body proteins (synthesis vs. degradation rates), being important for the maintenance of skeletal muscle mass, tissue that performs metabolic functions in the body and enables the performance of tasks of daily living. In addition, the practice of strength training (ST) interferes in muscle mass increasing rates, also exerting an influence in muscle quality, strength and power increase, which are associated with better physical fitness, quality of life and health. To make these increases possible, especially in relation to morphological aspects, a higher protein intake than recommended for the general population is necessary (1.2 to 1.6 g/kg/day), which requires careful dietary planning, especially when the consumption of meat, eggs and dairy products, which are important sources of this nutrient, is excluded. Thus, the present study has two main objectives: to compare the neuromuscular characteristics of strict vegetarians (VE) and non-vegetarians (NV) (Phase 1 - cross-sectional) and the neuromuscular adaptations induced by 16 weeks of ST (Phase 2 - longitudinal). For Phase 1, 140 healthy adults of both sexes (70 VE and 70 NV) will be recruited, who have been strength-untrained and who have adhered to the respective dietary pattern, both for at least 6 months. Participants will be instructed to perform the 3-day food record and count the number of steps for 5 days. Subsequently, they will undergo assessments of body composition, physical activity level and neuromuscular tests of the lower limbs (maximum strength, jumping power and muscle thickness of the quadriceps femoris, hamstring and gastrocnemius muscles). Comparisons of means between groups will be performed by the T test - independent. Results will be expressed as mean and standard deviation and the accepted significance level will be 5%. For Phase 2, 33 VE and 33 NV will be recruited (66 participants in total), who, in addition to meeting the eligibility criteria set out in Phase 1, are also available to participate in the strength training period. Participants will undergo the same assessments provided for in Phase 1 and must maintain their respective eating habits and patterns. At the 4th, 8th, 12th, and 16th weeks of ST, all participants will complete a new 3-day food record and perform step counts. In the 17th week, the initial evaluations will be repeated. Comparisons will be performed through two-way analysis of variance with repeated measures, considering the factors group (2 stratifications), time (2 stratifications) and group x time interaction. Results will be expressed as mean and standard deviation and the accepted significance level will be 5%.
研究设计
- 研究类型
- Interventional
- 分配方式
- Non Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Double (Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 19 Years 至 40 Years（Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •Body mass index until 30kg/m²
- •Be a strict vegetarian or non-vegetarian for at least 6 months
- •Not performing regular physical exercise for at least 6 months
排除标准
- •Having chronic diseases, such as systemic arterial hypertension, diabetes mellitus, cardiomyopathy
- •Present physical limitations or musculoskeletal problems, which contraindicate the performance of strength exercises
- •Make use of a protein or amino acid food supplement, caffeine or other thermogenic substances
研究组 & 干预措施
Strict vegetarians
Strict vegetarians women
干预措施: 16 weeks of strength training protocol (Other)
non vegetarians
Non vegetarians women
干预措施: 16 weeks of strength training protocol (Other)
结局指标
主要结局
Quadriceps femoris muscle thickness assessed by ultrasonography images
时间窗: Change from baseline at 16 weeks of strength training
Quadriceps femoris muscle thickness (vastus lateralis (VL) + rectus femoris (RF) + vastus medialis (VM) + vastus intermedius (VI) muscle thickness (MT, mm)) will be assessed by ultrasonography equipament. The RF and VI images will be assessed at two-thirds of the distance between the greater trochanter and the lateral epicondyle of the femur. VL images will be assessed at midpoint between greater trochanter and the lateal epicondyle of the femur. Thus, VM images will be assessed at the location corresponding to 30% of the distance between the lateral epicondyle and the greater trochanter of the femur. The images analisys will realized, posteriorly, by Image-J software.
Hamstrings muscle thickness assessed by ultrasonography images
时间窗: Change from baseline at 16 weeks of strength training
Hamstrings muscle thickness (i.e femural bíceps and semitendinosus muscle thickness; MT (mm)) will be assessed by ultrasonography images. Thi images will be obteined at 50% of distance between femur´s greater trochanter and the lateral line of the knee joint. In the image obtained, the muscle tissue between the adipose tissue interfaces will be identified, and the distance between these tissues will be defined as the muscle thickness. The analysis of the images will be carried out in the Image-J software.
Gastrocnemius muscle thickness assessed by ultrasonography images
时间窗: Change from baseline at 16 weeks of strength training
Will be asssesed by images obteined by ultrasonography equipament. The points for capturing the ultrasonography images of the gastrocnemius will be marked with a dermographic pen in the most medial cross-sectional area and with the greatest volume, verified with the probe. In the image obtained, the muscle tissue between the adipose tissue interfaces will be identified, and the distance between these tissues will be defined as the muscle thickness. The analysis of the images will be carried out in the Image-J software.
次要结局
- Rigth thigh dynamic muscle strength assessed by isokinetic dynamometer(Change from baseline at 16 weeks of strength training)
- Lower limb muscle power in the jumping performance test assessed by a contact mat(Change from baseline at 16 weeks of strength training)
- Knee extensors dynamic muscle strength assessed by one maximum repetition test(Change from baseline at 16 weeks of strength training)
- Knee flexors dynamic muscle strength assessed by one maximum repetition test(Change from baseline at 16 weeks of strength training)
- Quadriceps femoris muscle quality evaluated by echointensity through images obtained by ultrasonography.(Change from baseline at 16 weeks of strength training)
- Plantar flexors dynamic muscle strength assessed by one maximum repetition test(Change from baseline at 16 weeks of strength training)
- Hamstrings muscle quality evaluated by echointensity through images obtained by ultrasonography.(Change from baseline at 16 weeks of strength training)
- Gastrocnemius muscle quality evaluated by echointensity through images obtained by ultrasonography.(Change from baseline at 16 weeks of strength training in the gastrocnemius muscle quality evaluated by echointensity through images obtained by ultrasonography)
- Right thigh muscle quality estimated by specific tension(Change from baseline at 16 weeks of strength training)
- Gastrocnemius muscle quality estimated by specific tension(Change from baseline at 16 weeks of strength training)
- Daily protein intake relative to total body mass assessed by 3 day food record(At baseline, within 4, 8 and 12 weeks of starting strength training and with the end of the 16 weeks of strength training)
- Correlation between protein intake food and neuromuscular characteristics(Change from baseline at 16 weeks of strength training)
- Total food intake(At baseline, within 4, 8 and 12 weeks of starting strength training and with the end of the 16 weeks of strength training)
- Body composition assessed by Dual Energy X-Ray Emission Absorptiometry (DXA)(Change from baseline at 16 weeks of strength training)
- Body composition assessed by anthropometry measurements(Change from baseline at 16 weeks of strength training)
- Physical activity level assessed by International Physical Activity Questionnaire(Change from baseline at 16 weeks of strength training)
- Physical activity level assessed by daily step count(Change from baseline at 16 weeks of strength training)
研究者
Ronei Silveira Pinto
University Teacher/Doctor
Universidade Federal do Rio de Janeiro