Muscle Growth Following a Resistance Training Program in Men and Women Consuming Protein Supplements

Muscle Growth and Development Following a 12-week Resistance Training Program in Men and Women Consuming Soy and Whey Protein Supplements

Soy and whey protein have different concentrations of leucine, an amino acid known to be a particularly potent simulator of muscle protein synthesis. The purpose of this study is to determine whether matching soy and whey protein supplements for leucine content instead of by total protein content would contribute to differences in strength increases and muscle growth in response to 12 wk of resistance training.

Study Overview

• Status: Completed
• Conditions: Skeletal Muscle Growth
• Intervention / Treatment: Dietary supplement: Soy protein supplement; Dietary supplement: Whey protein supplement

• Study Type: Interventional
• Enrollment (Actual): 61
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Arizona
    • Phoenix, Arizona, United States, 85004
      • Arizona State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• non-smoking
• body mass index (BMI) 18.5-24.9
• recreationally active

Exclusion Criteria:

• participated in structured weight training during the previous 12 month
• vegetarian or vegan
• presence of chronic disease
• pregnant, postpartum up to six months, lactating, or intention to become pregnant
• allergy to whey or soy
• changes in body weight more than 10 pounds in the past three months

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Soy protein group	Dietary supplement: Soy protein supplement; 26 g soy protein isolate (contains 2 g leucine) was consumed daily by the other intervention group.
Active Comparator: Whey protein group	Dietary supplement: Whey protein supplement; 19 g whey protein isolate (contains 2 g leucine) was consumed daily by one intervention group.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lean Body Mass Change	assessed using dual energy x-ray absorptiometry (DEXA) scan for changes in lean body mass (kg)	Post-12 week intervention
Muscle Tissue Thickness Change	assessed using changes in muscle thickness assessed by ultrasound (cm)	Post-12 week intervention
Leg Girth Changes	assessed using circumference measurements (cm)	Post-12 week intervention

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Peak Torque When Doing Leg Extensions	Assessed using an isokinetic dynamometer set at 60 degrees of motion per second (d/s)	Post-12 week intervention

Collaborators and Investigators

• Sponsor: Point Loma Nazarene University
• Investigators: Principal Investigator: Heidi Lynch, PhD, Point Loma Nazarene University

Study record dates

Study Major Dates

• Study Start (Actual): August 15, 2016
• Primary Completion (Actual): April 30, 2017
• Study Completion (Actual): April 30, 2017

Study Registration Dates

• First Submitted: February 25, 2019
• First Submitted That Met QC Criteria: March 6, 2019
• First Posted (Actual): March 11, 2019

Study Record Updates

• Last Update Posted (Actual): February 27, 2020
• Last Update Submitted That Met QC Criteria: February 25, 2020
• Last Verified: February 1, 2020

More Information

Terms related to this study

• Other Study ID Numbers: 01435225

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No