Whey Protein Supplementation in High School Athletes

Effects of a Whey Protein Supplement on Performance, Recovery, and Body Composition in Adolescent Soccer Players During the Competitive Season

The overall aim of this project is to compare protein supplementation on performance, recovery, and body composition changes in adolescent soccer players between the whey protein and the control group in response to the 10-12-week intervention.

Study Overview

• Status: Completed
• Conditions: Sleep; Body Weight Changes; Recovery; Athletic Performance
• Intervention / Treatment: Dietary supplement: Whey Protein Supplement; Dietary supplement: Carbohydrate Placebo Control

Detailed Description

Informed Consent, Parental Permission and Assent: These will be obtained over Zoom, prior to participation in any study procedures.

Randomization: Randomization will occur following baseline testing. Participants will be randomized via random number generator stratified by sex, into either the whey protein supplement group or the placebo (isocaloric) control group.

Baseline and Post-Intervention testing will occur over a single day for each participant.

Baseline:

All athletes will report to testing facilities for a single blood draw to measure inflammatory biomarkers and a body composition assessment (via BodPod) to measure fat mass and fat free mass. Participants will then be escorted to a track where they will run a 30-yard dash to assess their speed and a 1.5-mile run to assess their estimated maximal rate of oxygen consumption (VO2max). Participants will then be transferred back to the testing facility where they will undergo assessment of lower body muscle fatigue (via HumacNorm).

Questionnaires: Athletes will complete the Munich Chronotype Questionnaire and the Pittsburg Sleep Quality Index (PSQI). Participants will also complete 3-day, 24-hour dietary recalls (via ASA-24).

Sleep measures: Fitbit (Inspire 2) will be used measure sleep efficiency, duration, and staging. Fitabase will be utilized to receive Fitbit data. Participants will be instructed to wear their Fitbit for 1-week.

Intervention:

In-season soccer practices and competition will occur 6-days per week across a 10-12 week period, depending on how far teams advance in postseason play. During the 10-12-weeks, participants will consume their assigned supplement or placebo twice per day, every day, immediately after practice or competition (or midday on rest days), and ~1 hour before bedtime.

Sleep measures: Sleep measures will be evaluated as described above. Sleep measures will be collected at weeks 2, 4, 6, 8, and 10.

Questionnaires: Participants will complete 3-days of 24-hour dietary recalls (via ASA-24) at weeks 5 and 10. Pittsburg Sleep Quality Index (PSQI), a delayed-onset muscle soreness questionnaire and a GI symptom Questionnaire will be completed at weeks 2, 4, 6, 8 and 10.

Urine Samples: We will randomly assign participants to provide urine samples at weeks 4 and 7 as a sham measure of compliance to supplementation protocol.

Post-testing will be the same as pre-testing and will commence after the 10-12-week competitive season. All measures described above in baseline testing will be repeated.

• Study Type: Interventional
• Enrollment (Actual): 31
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Utah
    • Salt Lake City, Utah, United States, 84112
      • Grace Zimmerman

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 13 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 13-18 years old; male and female High school soccer players

Exclusion Criteria:

• non-adolescents; untreated or underlying metabolic or cardiovascular diseases; allergies to dairy, or any allergies ingredients in the study provided granola bar or bagels, such as soy, wheat, tree nuts, peanuts, milk, and sesame.

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
Experimental: Whey Protein Supplement; Whey protein will come in powder form and will consist of 20g of protein, and 25.3g of product. We will use Optimum Nutrition Double Chocolate Whey Protein Isolate.	Dietary supplement: Whey Protein Supplement; Participants assigned to the intervention will consume the supplement mixed with 6-8oz of water every day, twice per day, after soccer practice or soccer games, and one hour before bedtime.; Other Names: Optimum Nutrition Gold Standard 100% Whey
Placebo Comparator: Carbohydrate Control; Carbohydrate control will come in powder form and will consist of 20g of carbohydrate and 21.6g of product. We will use Nesquik Chocolate Powder mix.	Dietary supplement: Carbohydrate Placebo Control; Participants assigned to the placebo control will consume the supplement mixed with 6-8oz of water every day, twice per day, after soccer practice or soccer games, and one hour before bedtime.; Other Names: Nesquik Chocolate Powder

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Estimated VO2max	Measured via 1.5-mile run time with participants running as quickly as they can.	Measured at baseline and post-intervention (10-12-weeks)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in Muscular Fatigue Via Repetitions to Fatigue	Measured via leg extension machine (HumacNorm) using isometric muscle contraction in the quadriceps muscle. Repetitions to fatigue was defined as the total number of consecutive maximal isometric contractions completed until force output declines below a predetermined threshold (e.g., <45% of peak torque).	Measured at baseline and post-intervention (10-12-weeks)
Changes in Speed	Measured using a 30 yard sprint	Measured at baseline and post-intervention (10-12-weeks)
Changes in Muscular Strength	This outcome is measured via maximum voluntary contraction from an isometric mid-thigh pull.	Measured at baseline and post-intervention (10-12-weeks)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in Fat Free Mass	Measured via BodPod to assess the amount of fat-free mass each participant has (kg)	Measured at baseline and post-intervention (10-12-weeks)
Changes in Fat Mass	Measured via BodPod to assess the amount of fat mass each participant has (kg)	Measured at baseline and post-intervention (10-12-weeks)
Sleep Efficiency	Measured via Fitbit devices. Sleep efficiency is measured based on how long and individual is asleep over the time spent in bed during the night.	Measured at baseline and post-intervention (10-12-weeks)
Sleep Duration	Measured via Fitbit devices. Sleep duration is measured based on how long the individual is asleep.	Measured at baseline and post-intervention (10-12-weeks)
Changes in Adiponectin	Measured via blood sample to assess levels of fatty acid oxidation as well as inflammation	Measured at baseline and post-intervention (10-12-weeks)
Changes in BDNF	Measured via blood sample	Measured at baseline and post-intervention (10-12-weeks)
Changes in Follistatin	Measured via blood sample to assess muscle hypertrophy	Measured at baseline and post-intervention (10-12-weeks)
Changes in Sleep Quality	Measured via Pittsburgh Sleep Quality Index questionnaire. The questionnaire consists of a combination of Likerttype and open-ended questions. Each component is scored from 0 to 3, with higher scores indicating greater sleep disturbance or poorer sleep quality. Component scores are summed to yield a global PSQI score ranging from 0 to 21. A global PSQI score >5 is commonly used to indicate poor sleep quality, whereas scores ≤5 indicate relatively good sleep quality. Each component is scored from 0 to 3, with higher scores indicating greater sleep disturbance or poorer sleep quality. Component scores are summed to yield a global PSQI score ranging from 0 to 21.	Measured at baseline and post-intervention (10-12-weeks)
Protein Intake	Measured via a 3-day food recall	Measured at baseline and post-intervention (10-12-weeks)

Collaborators and Investigators

• Sponsor: University of Utah
• Investigators: Principal Investigator: Tanya Halliday, PhD, University of Utah

Publications and helpful links

General Publications

• Zimmerman G, Mmp de Hart N, Ou I, Miranda V, Bastian E, Drummond M, Depner C, Halliday T. The effects of whey protein supplementation on athletic performance and body composition in adolescent soccer players: a randomized controlled trial. Appl Physiol Nutr Metab. 2026 Jan 1;51:1-9. doi: 10.1139/apnm-2025-0325.

Study record dates

Study Major Dates

• Study Start (Actual): July 14, 2022
• Primary Completion (Actual): October 28, 2022
• Study Completion (Actual): October 28, 2022

Study Registration Dates

• First Submitted: October 17, 2022
• First Submitted That Met QC Criteria: October 19, 2022
• First Posted (Actual): October 21, 2022

Study Record Updates

• Last Update Posted (Actual): April 27, 2026
• Last Update Submitted That Met QC Criteria: April 6, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Body Weight Changes; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Beverages; Dairy Products; Milk; Whey
• Other Study ID Numbers: 00145632

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Request for deidentified data can be made to the PI on a case-by-case basis.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No