Dietary Supplements, Muscle Strength, Muscle, Skeletal, Resistance Training, Diet Habit
Conditions
Brief summary
This is a randomized controlled trial aimed to investigate the effects of different supplementary protein sources on muscle adaptations to resistance exercise. Young, healthy, recreationally active participants consuming an omnivorous diet with protein intake within recommended dietary allowance (RDA) (i.e.; 0.8-1.0 g.kg-1. d-1) will be recruited to undergo a 12-wk supervised resistance training program in combination with the intake of three 15-g daily doses (45g. d-1 total) of either a mixed plant- (i.e.; soy and pea protein) or animal-based (i.e.; whey protein) protein in drink form as a supplementary source of protein to their main meals of the day (i.e.; breakfast, lunch, and dinner). Before (PRE) and after (POST) the 12-wk intervention, participants will be assessed for body composition by dual-energy X-ray absorptiometry (DXA), muscle cross-sectional area (ultrasound) and fiber cross-sectional area (muscle biopsy), and maximal isotonic strength (1RM). Training consists of a resistance training (RT) program individually supervised by a researcher blinded to treatment in a laboratorial setting. Assessments will also be conducted in a blinded fashion.
Interventions
DIETARY_SUPPLEMENTAnimal protein
Patients allocated to this arm will be submitted a supervised resistance training program in combination with the intake of three 15-g daily doses (45g. d- 1 total) animal-based protein (i.e.; whey protein) in drink form as a supplementary source of protein in their main meals of the day.
DIETARY_SUPPLEMENTPlant Protein
Patients allocated to this arm will be submitted a supervised resistance training program in combination with the intake of three 15-g daily doses (45g. d- 1 total) mixed plant protein (i.e.; soy and pea) in drink form as a supplementary source of protein in their main meals of the day.
Sponsors
NotCo Brasil Distribuicao e Comercio de Produtos Alimenticios LTDA
University of Sao Paulo General Hospital
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Physically active (according to the International Physical Activity Questionnaire (IPAQ) * Absence of any chronic condition that could preclude participation in a RT program or physical testing * Habitual protein consumption within RDA ≥ 0.8 ≤1.0 g.kg-1. d-1
Exclusion criteria
* Prior history of anabolic steroids use, current or previous (≤ 3 m) * Use of ergogenic or protein-based supplements, current or previous (\< 1 y) * Engagement in energy-restricted diets
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| vastus lateralis muscle cross sectional area | Ultrasound images will be obtained both at baseline (before the comencement of the study) and immediately after the 12-week intervention period | the investigators used ultrasound measures of the vastus lateralis cross sectional area as the primary outcome |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| lean mass | DXA scans will be taken both at baseline (before the comencement of the study) and immediately after the 12-week intervention period | total body and lower limb lean mass assessed by DXA |
| fiber cross sectional area | Fiber cross sectional areas will be measured both at baseline (before the comencement of the study) and immediately after the 12-week intervention period | vastus lateralis fiber cross sectional area from muscle biopsy samples |
| maximal isotonic strength | 1-RM tests will be taken both at baseline (before the comencement of the study) and immediately after the 12-week intervention period | lower-limb maximal isotonic strength will be assessed in the leg-press exercise by means of the one-repetition-maximum test (1-RM test) |
Countries
Brazil
Outcome results
None listed