---
title: Muscle Growth Following a Resistance Training Program in Men and Women Consuming Protein Supplements
nct_id: NCT03868631
overall_status: COMPLETED
phase: NA
sponsor: Point Loma Nazarene University
study_type: INTERVENTIONAL
primary_condition: Skeletal Muscle Growth
countries: United States
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT03868631.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT03868631"
ct_last_update_post_date: 2020-02-27
last_seen_at: "2026-05-12T07:10:35.385Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Muscle Growth Following a Resistance Training Program in Men and Women Consuming Protein Supplements

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

**NCT ID:** [NCT03868631](https://clinicaltrials.gov/study/NCT03868631)

## Key Facts

- **Status:** COMPLETED
- **Phase:** NA
- **Study Type:** INTERVENTIONAL
- **Target Enrollment:** 61
- **Lead Sponsor:** Point Loma Nazarene University
- **Conditions:** Skeletal Muscle Growth
- **Start Date:** 2016-08-15
- **Completion Date:** 2017-04-30
- **CT.gov Last Update:** 2020-02-27

## Brief Summary

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.

## Eligibility

- **Minimum age:** 18 Years
- **Maximum age:** 35 Years
- **Sex:** ALL
- **Healthy Volunteers:** Yes

```
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
```

## Arms

- **Soy protein group** (ACTIVE_COMPARATOR)
- **Whey protein group** (ACTIVE_COMPARATOR)

## Interventions

- **Whey protein supplement** (DIETARY_SUPPLEMENT) — 19 g whey protein isolate (contains 2 g leucine) was consumed daily by one intervention group.
- **Soy protein supplement** (DIETARY_SUPPLEMENT) — 26 g soy protein isolate (contains 2 g leucine) was consumed daily by the other intervention group.

## Primary Outcomes

- **Lean Body Mass Change** _(time frame: Post-12 week intervention)_ — assessed using dual energy x-ray absorptiometry (DEXA) scan for changes in lean body mass (kg)
- **Muscle Tissue Thickness Change** _(time frame: Post-12 week intervention)_ — assessed using changes in muscle thickness assessed by ultrasound (cm)
- **Leg Girth Changes** _(time frame: Post-12 week intervention)_ — assessed using circumference measurements (cm)

## Secondary Outcomes

- **Change in Peak Torque When Doing Leg Extensions** _(time frame: Post-12 week intervention)_

## Locations (1)

- Arizona State University, Phoenix, Arizona, United States

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.phases` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.maxAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.arizona state university|phoenix|arizona|united states` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT03868631.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT03868631*  
*This page is a raw mirror with no AI summary, no editorial enrichment, and no Parkinson's-specific filtering.*