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CompletedNCT05576337Updated Oct 15, 2024

Neuromuscular Characteristics of Strict Vegetarians and Non-Vegetarians Women

An interventional study of 16 weeks of strength training protocol in Hypertrophy, sponsored by Universidade Federal do Rio de Janeiro. Completed at 1 site in Brazil. Open to female participants aged 19 Years to 40 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-10-15.

Sponsored by Universidade Federal do Rio de Janeiro · Not applicable, Interventional, and Basic science

From the registry’s dates

  • Registered 4 months after the study started (first participant enrolled May 2022, registered Sep 2022).
Phase
Not applicable
Study type
Interventional
Enrollment
128
Allocation
Non-randomized
Ages
19 Years to 40 Years
Sex
Female
01

Study summary

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).

Read the detailed description

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%.

02

Conditions studied

  • Hypertrophy

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Keywords

  • Muscle mass
  • Muscle quality
  • Strength
  • Power
03

In context

Hypertrophy

655 studies on the registry are indexed under Hypertrophy; 86 are open to participants now.

This study's enrollment of 128 is above the median of 50 across 460 interventional studies indexed under Hypertrophy.

Browse Hypertrophy studies →

Lead sponsor

Universidade Federal do Rio de Janeiro is the lead sponsor of 123 studies on the registry; 11 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
19 Years to 40 Years
Sexes eligible
Female
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • 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

Exclusion criteria

Exclusion Criteria:

  • 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
05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
Double (Investigator, Outcomes assessor)
Enrollment
128 participants (actual)

Study arms

  • Experimental
    Strict vegetarians

    Strict vegetarians women

    Other: 16 weeks of strength training protocol

  • Experimental
    non vegetarians

    Non vegetarians women

    Other: 16 weeks of strength training protocol

Interventions

  • Other16 weeks of strength training protocol

    16 weeks of strength training protocol

06

What researchers measure

Primary outcomes

  1. Quadriceps femoris muscle thickness assessed by ultrasonography images

    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.

    Time frame: Change from baseline at 16 weeks of strength training

  2. Hamstrings muscle thickness assessed by ultrasonography images

    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.

    Time frame: Change from baseline at 16 weeks of strength training

  3. Gastrocnemius muscle thickness assessed by ultrasonography images

    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.

    Time frame: Change from baseline at 16 weeks of strength training

Secondary outcomes

  1. Lower limb muscle power in the jumping performance test assessed by a contact mat

    To evaluate the muscle power of the lower limbs, a jump test with counter-movement bilaterally will be used. 3 to 5 submaximal jumps will be conducted for possible performance adjustments. At 5 minutes rest, the submaximal tests will be executed. The participant will perform the maximum jump as quickly and powerfully as possible, and the average of 3 jumps, separated by 30s, will be used as a performance result. The evaluations will be conducted on a contact mat which will automatically inform the performance of the participants

    Time frame: Change from baseline at 16 weeks of strength training

  2. Rigth thigh dynamic muscle strength assessed by isokinetic dynamometer

    The right thigh muscle strength will be assessed using peak torque (PT, N.m) obteined by isokinetic dynamometer. Will be realized 5 maximal concentric isokinetic contractions of knee extension and flexion, with a velocity of 60º.s-1 and range of motion between zero (maximum extension) and 90º of knee flexion. In addition, will be realized 5 eccentric knee flexion contractions with the same speed and amplitude as in the previous test. Between each dynamic test, a 1-minute interval will be observed and, before performing each test, a submaximal familiarization series with the same number of repetitions, speed and range of motion will be performed. The participant will be instructed to perform all tests "as quickly and as hard as possible". In addition, the participant will receive verbal stimulation during the tests.

    Time frame: Change from baseline at 16 weeks of strength training

  3. Knee extensors dynamic muscle strength assessed by one maximum repetition test

    Will be evaluated by 1 maximum repetition (1MR) test of knee extensors muscles to be performed in KONNEN GYM® equipments. The 1 maximum repetition test load (kg) will be estimated through trial and error. Lombardi correction coefficients will be used to adjust the load between trials. The exercise will consist of performing the concentric phase, starting from the initial position (90º of knee flexion) to the final phase (maximum knee extension), and returning to the initial position, eccentric phase. To minimize the effect of fatigue on the test result, 3-minute intervals will be observed for warm-up, as well as between each load increment. The 1MR load will be considered the one in which the participant can perform only one maximum repetition with cadence (2 seconds for the concentric phase and 2 seconds for the eccentric phase) and desired range of motion (from the position of 90º of knee flexion to the maximum knee extension position).

    Time frame: Change from baseline at 16 weeks of strength training

  4. Knee flexors dynamic muscle strength assessed by one maximum repetition test

    Will be evaluated by 1 maximum repetition (1MR) test of hamstrings muscles to be performed in KONNEN GYM® flexion equipment. The 1 maximum repetition test load (kg) will be estimated through trial and error. Lombardi correction coefficients will be used to adjust the load between trials. The exercise will consist of performing the concentric phase, starting from the initial position (180º of knee extension) to the final phase (90° knee flexion), and returning to the initial position, eccentric phase. To minimize the effect of fatigue on the test result, 3-minute intervals will be observed for warm-up, as well as between each load increment. The 1MR load will be considered the one in which the participant can perform only one maximum repetition with cadence (2 seconds for the concentric phase and 2 seconds for the eccentric phase) and desired range of motion (from the position of 180º of knee extension to the 90° knee flexion position).

    Time frame: Change from baseline at 16 weeks of strength training

  5. Plantar flexors dynamic muscle strength assessed by one maximum repetition test

    Will be evaluated by 1 maximum repetition (1MR) test of plantar flexors muscles to be performed in KONNEN GYM® plantar flexion equipment. The 1 maximum repetition test load (kg) will be estimated through trial and error. Lombardi correction coefficients will be used to adjust the load between trials. The exercise will consist of performing the concentric phase, starting from the initial position (45° of ankle flexion) to the final phase (45° ankle flexion), and returning to the initial position, eccentric phase. To minimize the effect of fatigue on the test result, 3-minute intervals will be observed for warm-up, as well as between each load increment. The 1MR load will be considered the one in which the participant can perform only one maximum repetition with cadence (2 seconds for the concentric phase and 2 seconds for the eccentric phase) and desired range of motion (from the position of 180º of knee extension to the 90° knee flexion position).

    Time frame: Change from baseline at 16 weeks of strength training

  6. Quadriceps femoris muscle quality evaluated by echointensity through images obtained by ultrasonography.

    The muscle quality by echo-intensity of the quadriceps femoris muscle will be obtained from images collected for the measurement of muscle thickness, using an ultrasonography device. The largest muscle area of interest will be delimited without considering fascia and bone, and the analysis will be based on a gray scale histogram where 0 is black and 255 is white. The analysis will be performed using the same software (ImageJ, version 1.37, National Institutes of Health, USA) and the average of the values of three captured images will be used for further analysis.

    Time frame: Change from baseline at 16 weeks of strength training

  7. Hamstrings muscle quality evaluated by echointensity through images obtained by ultrasonography.

    The muscle quality by echo-intensity of the hamstrings muscles will be obtained from images collected for the measurement of muscle thickness, using an ultrasonography device. The largest muscle area of interest will be delimited without considering fascia and bone, and the analysis will be based on a gray scale histogram where 0 is black and 255 is white. The analysis will be performed using the same software (ImageJ, version 1.37, National Institutes of Health, USA) and the average of the values of three captured images will be used for further analysis.

    Time frame: Change from baseline at 16 weeks of strength training

  8. Gastrocnemius muscle quality evaluated by echointensity through images obtained by ultrasonography.

    The muscle quality by echo-intensity of the gastrocnemius muscles will be obtained from images collected for the measurement of muscle thickness, using an ultrasonography device. The largest muscle area of interest will be delimited without considering fascia and bone, and the analysis will be based on a gray scale histogram where 0 is black and 255 is white. The analysis will be performed using the same software (ImageJ, version 1.37, National Institutes of Health, USA) and the average of the values of three captured images will be used for further analysis.

    Time frame: Change from baseline at 16 weeks of strength training in the gastrocnemius muscle quality evaluated by echointensity through images obtained by ultrasonography

  9. Right thigh muscle quality estimated by specific tension

    It will be determined by the ratio between the value of the concentric peak torque (N.m) of the right knee extensors and flexors, determined by an isokinetic dynamometer test, and the value of the lean mass (kg) of the right thigh, obtained by Dual Energy X-Ray Emission Absorptiometry, in which a region of interest of the thigh will be evaluated through the manual construction of a box.

    Time frame: Change from baseline at 16 weeks of strength training

  10. Gastrocnemius muscle quality estimated by specific tension

    It will be determined by the ratio between the value of the one maximum repetition (Kg) of the right plantar flexors, determined by an one maximum repetition test, and the value of the lean mass (kg) of the right leg, obtained by Dual Energy X-Ray Emission Absorptiometry, in which a region of interest of the thigh will be evaluated through the manual construction of a box.

    Time frame: Change from baseline at 16 weeks of strength training

  11. Daily protein intake relative to total body mass assessed by 3 day food record

    Daily protein intake relative to total body mass will be assessed by 3 day food record that will be realized by Dietbox software. The records must include the times, quantities in household measures and, when possible, the brand of the food product. In addition, each participant will make a photographic record of each meal (dish served/package/food), to assist in understanding food intake. A photographic material will be provided with the size of the portions to assist in filling in homemade measures. The records will be analyzed with the same software, preferably using the data registered in the Food Composition Table (TACO) (NEPA; UNICAMP, 2011), Food composition table: support for nutritional decision (PHILIPPI, 2016), Brazilian Table of Food Composition (TBCA) (USP; FORC, 2020) and food label.

    Time frame: At baseline, within 4, 8 and 12 weeks of starting strength training and with the end of the 16 weeks of strength training

  12. Correlation between protein intake food and neuromuscular characteristics

    The protein food intake relative to total body mass assessed by 3 day food record will be correlated with neuromuscular characteristics (Quadriceps femoris, hamstrings and gastrocnemius muscle thickness assessed by ultrasonography images; lower limb muscle power in the jumping performance test assessed by a contact mat; rigth thigh dynamic muscle strength assessed by isokinetic dynamometer; knee extensors, knee flexors and plantar flexors dynamic muscle strength assessed by one maximum repetition test; quadriceps femoris, hamstrings and gastrocnemius muscle quality evaluated by echointensity through images obtained by ultrasonography; right thigh and gastrocnemius muscle quality estimated by specific tension).

    Time frame: Change from baseline at 16 weeks of strength training

  13. Total food intake

    Total food intake will be assessed by 3 day food record ijn the same way that daily protein intake relative to total body mass outcome The total amounts (g, mg) of nutrients (calories, carbohydrates, fats, protein, amino acids, iron, zinc, calcium, selenium, vitamins D, B12) will be evaluated and relativized by body mass (proteins), ingested on the day and by snack.

    Time frame: At baseline, within 4, 8 and 12 weeks of starting strength training and with the end of the 16 weeks of strength training

  14. Body composition assessed by Dual Energy X-Ray Emission Absorptiometry (DXA)

    The total and regional bone content (kg), boné mineral density (kg/cm²), fat (kg) and lean mass (kg) will be assessed with absorption by dual energy x-ray emission (DXA). During the test, participants will be positioned in supine position, aligned and centered on the examination table with hips and shoulders extended to initiate the X-ray scan. Also, they will be instructed to wear light clothes at the time of the assessment, which allow adequate body scanning, in addition to not wearing metal accessories. The radiation that the participant will be exposed during the evaluation is safe and less than 1μSv (BOLANOWSKI; NILSSON, 2001). The equipment will be calibrated before each scan according to the manufacturer's specifications. The obteined images will be evaluated later using the software (Encore versão 41.1, Lunar Prodgy Madison, USA).

    Time frame: Change from baseline at 16 weeks of strength training

  15. Body composition assessed by anthropometry measurements

    The Body mass (kg) and Heigh (cm) will be assesed for the body mass index (BMI) calculation as inclusion criteria, that will be classified according world health organization (WHO, 2000) parameters. Participants will be evaluated wearing light clothes and barefoot on an ASIMED® scale with a resolution of 0.1 kg. The heigh will be assessed with wall scale. Perimeters (cm), skinfolds (mm), bone diameters and lengths (cm) also will be assessed. The total and regional body composition analisys will be realized. All measurements will follow the standardization protocol of measurements made by ISAK (International Society for the Advancement of Kinanthropometry) and will be assessed in the high side of the body, in duplicate, if necessary in triplicate, and the mean, mode or median will be used, as final result.

    Time frame: Change from baseline at 16 weeks of strength training

  16. Physical activity level assessed by International Physical Activity Questionnaire

    Participants will receive a printed copy of the short version of the International Physical Activity Questionnaire, which is self-applied and validated for the Brazilian population (CRAIG et al., 2003; MATSUDO et al., 2001). The Questionnaires will be analyzed and classified according to the tool's categorical score as "low", "moderate" and "high" physical activity level.

    Time frame: Change from baseline at 16 weeks of strength training

  17. Physical activity level assessed by daily step count

    The evaluation of the counting of the daily steps will be assessed by daily step count, that will be evaluated during 7 days at baseline and after 16s weeks of strength training. For this, participants will receive a pedometer.

    Time frame: Change from baseline at 16 weeks of strength training

07

Study locations

1 site
  • Federal University of Rio Grande do Sul (UFRGS)
    Porto Alegre, Rio Grande do Sul, Brazil
08

References and documents

Publications

  • Martini GL, Schemes MB, Strey B, Schneider CD, de Souza CG, Pinto RS. No Differences in Muscular Adaptations to Long-Term Resistance Training Between Young Strict Vegetarian and Non-Vegetarian Women. Scand J Med Sci Sports. 2026 Feb;36(2):e70224. doi: 10.1111/sms.70224. PubMed 41684167 ↗

Study documents

  • Protocol, analysis plan and consent form · Mar 28, 2022

Documents are hosted by the registry — open the source record to download them.

Individual participant data

Plan to share: No

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Ran from May 2022 to primary completion in Dec 2023, 19 months.

Of 152 non-industry interventional studies with no phase under Hypertrophy, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 9 and three quarters within 33. This study's 19 months is close to that.

Counting every sponsor, half of 167 studies reached it within 19 months; a quarter within 9 and three quarters within 35.

How these figures are worked out, and which studies are left out of them.

Registered
Sep 23, 2022
First posted
Oct 12, 2022
StartActual
May 1, 2022
Primary completionActual
Dec 13, 2023
CompletionActual
Oct 13, 2024
Last update
Oct 15, 2024
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Oct 15, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05576337
Responsible party
Ronei Silveira Pinto (University Teacher/Doctor, Universidade Federal do Rio de Janeiro) — Principal investigator
First posted
Oct 12, 2022
Start date
May 1, 2022
Primary completion
Dec 13, 2023
Completion
Oct 13, 2024
Last update
Oct 15, 2024

Study contacts

Ronei Silveira Pinto
principal investigator · Federal University of Rio Grande do Sul (UFRGS)
Claúdia Dornelles Schneider
study director · Federal University of Healthy Sciences of Porto Alegre (UFCSPA)

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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