Influence of Caffeinated and Non-caffeinated Pre-workout Supplements on Resistance Exercise Performance

This study is a randomized, double-blind, placebo-controlled crossover trial examining the effects of caffeinated and non-caffeinated pre-workout supplements on resistance exercise performance. Resistance-trained adults will be randomly assigned to complete three study conditions (caffeinated pre-workout, non-caffeinated pre-workout, and placebo) in one of the six possible condition orders. During each condition, participants will report to the laboratory for ingestion of the assigned beverage and subsequent muscular performance testing. Major performance outcomes will be force production variables from a mechanized squat device and maximal strength and muscular endurance on the bench press and leg press exercises.

Study Overview

• Status: Completed
• Conditions: Caffeine; Resistance Training; Dietary Supplements
• Intervention / Treatment: Dietary supplement: Caffeinated pre-workout supplement; Dietary supplement: Non-caffeinated pre-workout supplement; Dietary supplement: Placebo

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Texas
    • Lubbock, Texas, United States, 79409
      • Department of Kinesiology & Sport Management

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 38 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Between the ages of 18 and 40;
• Body mass between 50 - 100 kg (110-220 lb)
• Generally healthy (defined as an absence of any disease or medical condition which could potentially be negatively affected by consumption of the commercially available dietary supplements or performance of exercise, including but not limited to musculoskeletal or cardiovascular diseases).
• Resistance-trained, defined as completing 2+ resistance training sessions per week for at least three months prior to screening.
• Participants must have reported regular training of the lower body through a multi-joint exercise such as the squat or leg press at least once weekly during the three-month period prior to screening.
• Participants must have reported regular training of the bench press or chest press variation at least once weekly during the three-month period prior to screening.
• Female participants will be required to bench press ≥ 0.5 x body mass and leg press ≥ 1.75 x body mass during initial 1RM assessments to be eligible for this study.
• Male participants will be required to bench press ≥ 1.0 x body mass and leg press ≥ 3.0 x body mass to be eligible.
• Regular caffeine consumption (due to the presence of caffeine in the commercially available dietary supplement). This will be defined as an average self-reported daily intake of 250+ mg of caffeine, which is equivalent to approximately 2.5 cups of coffee.

Exclusion Criteria:

• Failing to meet any of the aforementioned inclusion criteria.
• Pregnant or breastfeeding (for female participants)
• Taking prescription medication which could reasonably make participation unsafe for the participant or influence study outcomes
• An inability to complete resistance exercise due to injury or medical condition
• Self-reported caffeine sensitivity, as indicated by unwanted side effects when caffeine is consumed.
• Allergy to any of the ingredients in the test beverages or standardized breakfast.
• Current use of anabolic steroids
• Presence of a pacemaker or other implanted electrical device.
• Unwillingness to wear the provided surgical mask during all testing procedures.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Caffeinated Pre-workout Supplement; This arm will consist of ingestion of the commercially available, caffeinated Pulse pre-workout, manufactured by Legion Athletics, Inc.	Dietary supplement: Caffeinated pre-workout supplement; The intervention will consist of consuming a standardized meal followed by one serving of the commercially available Pulse caffeinated pre-workout supplement (Legion Athletics, Inc.).; Other Names: Legion Athletics Pulse Pre-workout Supplement
Active Comparator: Non-Caffeinated Pre-Workout Supplement; This arm will consist of ingestion of the commercially available, non-caffeinated Pulse pre-workout, manufactured by Legion Athletics, Inc.	Dietary supplement: Non-caffeinated pre-workout supplement; The intervention will consist of consuming a standardized meal followed by one serving of the commercially available Pulse non-caffeinated pre-workout supplement (Legion Athletics, Inc.).; Other Names: Legion Athletics Pulse Pre-workout Supplement
Placebo Comparator: Placebo; This arm will consist of a flavor-matched placebo beverage without the active components contained in the supplements administered in the other study arms.	Dietary supplement: Placebo; The intervention will consist of consuming a standardized meal followed by a placebo beverage.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Isometric Peak Force Production	Peak isometric force produced on a mechanical squat device at an 120-degree knee angle.	Approximately 35 minutes after beverage ingestion in each condition.
Isometric Rate of Force Development	Rate of force development produced on a mechanical squat device at an 120-degree knee angle.	Approximately 35 minutes after beverage ingestion in each condition.
Isokinetic Peak Concentric Force Production	Peak concentric force produced during isokinetic testing on a mechanical squat device.	Approximately 40 minutes after beverage ingestion in each condition.
Isokinetic Peak Eccentric Force Production	Peak eccentric force produced during isokinetic testing on a mechanical squat device.	Approximately 40 minutes after beverage ingestion in each condition.
Maximal Strength on Bench Press Exercise	One-repetition maximum for the barbell bench press exercise.	Approximately 65 minutes after beverage ingestion in each condition.
Muscular Endurance on Bench Press Exercise	Repetitions to failure on the bench press exercise, using a load corresponding to 0.4 times body mass for females and 0.75 times body mass for males.	Approximately 70 minutes after beverage ingestion in each condition.
Maximal Strength on Leg Press Exercise	One-repetition maximum for the plate-loaded leg press exercise.	Approximately 95 minutes after beverage ingestion in each condition.
Muscular Endurance on Leg Press Exercise	Repetitions to failure on the leg press exercise, using a load corresponding to 1.5 times body mass for females and 2.5 times body mass for males.	Approximately 100 minutes after beverage ingestion in each condition.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subjective Ratings of Energy	Subjective rating of energy as indicated by visual analog scale (0 to 100, with a higher value indicating a higher rating of energy).	Five total assessments in each condition. Immediately prior to: beverage ingestion, isometric exercise testing, bench press testing, and leg press testing. Also, immediately after leg press testing.
Subjective Ratings of Focus	Subjective rating of focus as indicated by visual analog scale (0 to 100, with a higher value indicating a higher rating of focus).	Five total assessments in each condition. Immediately prior to: beverage ingestion, isometric exercise testing, bench press testing, and leg press testing. Also, immediately after leg press testing.
Subjective Ratings of Fatigue	Subjective rating of fatigue as indicated by visual analog scale (0 to 100, with a higher value indicating a higher rating of fatigue).	Five total assessments in each condition. Immediately prior to: beverage ingestion, isometric exercise testing, bench press testing, and leg press testing. Also, immediately after leg press testing.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Participant Identification of Beverage	At the end of each exercise session (i.e., after leg press testing has concluded), participants will be asked to identify the test beverage they believe they received.	At the very end of each condition (i.e., approximately 105 minutes after beverage ingestion in each condition; exact time of assessment may vary based on duration of exercise performance testing for each participant).

Collaborators and Investigators

• Sponsor: Texas Tech University
• Collaborators: Legion Athletics, Inc

Study record dates

Study Major Dates

• Study Start (Actual): February 23, 2021
• Primary Completion (Actual): May 11, 2021
• Study Completion (Actual): May 11, 2021

Study Registration Dates

• First Submitted: January 11, 2021
• First Submitted That Met QC Criteria: January 14, 2021
• First Posted (Actual): January 15, 2021

Study Record Updates

• Last Update Posted (Actual): June 3, 2021
• Last Update Submitted That Met QC Criteria: June 2, 2021
• Last Verified: June 1, 2021

More Information

Terms related to this study

• Keywords: resistance exercise; caffeine; dietary supplements; resistance training; pre-workout supplement
• Other Study ID Numbers: IRB2020-813; 20-1299 (Other Identifier: Texas Tech University Sponsored Projects)

Drug and device information, study documents

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