Protein Requirements in Resistance-trained Males

Healthy Clinical Trial

Official title:

Protein Requirements in Resistance-trained Males

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03696264
• Other study ID #: RTM
• Status: Completed
• Phase: N/A
• Start date: March 6, 2017
• Est. completion date: October 31, 2017

Study information

• Verified date: October 2018
• Source: University of Toronto
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

In this study, the investigators will use the minimally invasive indicator amino acid oxidation (IAAO) technique to determine protein requirements in resistance-trained males. It is hypothesized that the present study will show that protein requirements for resistance-trained males are i) greater than the current recommended dietary allowance (RDA) for non-active individual's comparable estimates, and ii) greater than existing nitrogen balance-based estimates for resistance-training individuals.

Description:

The adequate ingestion of dietary protein is the most critical nutritional factor to support the growth and maintenance of lean body mass across the lifespan. Currently, the World Health Organization/Food and Agricultural Organization (WHO/FAO) suggest that daily protein requirements in healthy, non-active adults are 0.8 g/kg/day. However, of primary interest in the present study is the impact that exercise has on the nutritional requirement for dietary protein in habitually active adults (e.g., individuals performing chronic resistance training). Protein requirements for individuals who participate in strength-based exercise training have been suggested to range from 1.2-1.7 g protein/kg/day (1), which equates to a 50-112% increase from the current RDA. The increased requirement in strength training populations may reflect the requirement for protein to repair and/or rebuild muscle tissue by promoting anabolism (2). Nutritional requirements for dietary protein in adults (both active and non-active) have traditionally been determined utilizing the antiquated and often erroneous nitrogen balance (NBAL) technique (3), which is prone to underestimating protein requirements and therefore provides challenges to making accurate nutritional recommendations (4). This observation that NBAL underestimates protein requirements in non-active individuals could suggest that protein requirements are much greater than the current World Health Organization recommendation of 0.8 g/kg/day, which was evaluated using the NBAL technique (3). As a result, there is a need to re-evaluate recommendations utilizing advanced stable isotope methodology in order to characterize how dietary protein needs may be modulated by physical activity. Recent studies using the minimally invasive indicator amino acid oxidation (IAAO) technique have suggested that protein requirements in young men are at least 50% higher than WHO/FAO guidelines based on NBAL data (4). Furthermore, resistance training has been reported to increase (according to NBAL methodology) protein requirements by up to 75% (6). Therefore, in this study, the investigators will use the IAAO technique to determine protein requirements in resistance-trained males. It is hypothesized that protein requirements for resistance-trained males will be i) greater than the current RDA for non-active individual's comparable estimates, and ii) greater than existing NBAL-based estimates for resistance-training individuals.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 7
• Est. completion date: October 31, 2017
• Est. primary completion date: July 1, 2017
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 18 Years to 35 Years

Eligibility

Inclusion Criteria:

• Healthy, male weight-trained individuals that have trained consistently for >1 year.

• 18-35 years old.

• Train each muscle group (i.e. chest, back, legs) at least twice a week.

• Body mass stable in last month

• Meets strength relative to body weight guidelines (see below)

Bench Press:

Males- body weight (kg)*1.25

Leg Press:

Males- body weight (kg)* 4.0

Exclusion Criteria:

• Inability to meet health and physical activity guidelines according to the Physical Activity Readiness Questionnaire

• Inability to adhere to any of the protocol guidelines (i.e. alcohol, caffeine consumption)

• Regular tobacco use

• Illicit drug use (e.g. growth hormone, testosterone, etc.) (screened by survey sheet for training log

• >1 month sedentary in the last 6 months prior to study participation

• >30 min of continuous cardio per exercise session

• BMI (Body Mass Index) > 35.

• Individual plans to increase or decrease body mass in the next 3 months

• Habitually ingests greater than or equal to 3g protein kg/bw/day

• Use of supplements such as creatine and beta-alanine in the last 30 days.

Related Conditions & MeSH terms

• Healthy

Intervention

Dietary Supplement:
• Amino acid intake
Amino acid intake will range between 0.2-3.0g/kg/d

Locations

Country	Name	City	State
Canada	Goldring Centre for High Performance Sport	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
University of Toronto

Country where clinical trial is conducted

Canada, 

References & Publications (5)

Humayun MA, Elango R, Ball RO, Pencharz PB. Reevaluation of the protein requirement in young men with the indicator amino acid oxidation technique. Am J Clin Nutr. 2007 Oct;86(4):995-1002. — View Citation

Phillips SM. Protein requirements and supplementation in strength sports. Nutrition. 2004 Jul-Aug;20(7-8):689-95. Review. — View Citation

Rand WM, Pellett PL, Young VR. Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults. Am J Clin Nutr. 2003 Jan;77(1):109-27. — View Citation

Tarnopolsky MA, Atkinson SA, MacDougall JD, Chesley A, Phillips S, Schwarcz HP. Evaluation of protein requirements for trained strength athletes. J Appl Physiol (1985). 1992 Nov;73(5):1986-95. — View Citation

Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet. 2016 Mar;116(3):501-528. doi: 10.1016/j.jand.2015.12.006. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Phenylalanine excretion	Expressed as µmol/kg/h; phenylalanine excretion is determined via breath enrichment of the oral tracer	Through study completion, an average of 1 year
Secondary	Phenylalanine rate of appearance	In µmol/kg/h; phenylalanine rate of appearance is determined via urinary enrichment of the oral tracer	Through study completion, an average of 1 year
Secondary	Net Protein Balance	In µmol/kg/h; calculated as the difference between whole-body protein synthesis and protein breakdown	Through study completion, an average of 1 year