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 Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
TRIPLE
Enrollment
24
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.).
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.).
The intervention will consist of consuming a standardized meal followed by a placebo beverage.
Department of Kinesiology & Sport Management
Lubbock, Texas, United States
Isometric Peak Force Production
Peak isometric force produced on a mechanical squat device at an 120-degree knee angle.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Approximately 40 minutes after beverage ingestion in each condition.
Maximal Strength on Bench Press Exercise
One-repetition maximum for the barbell bench press exercise.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: Approximately 100 minutes after beverage ingestion in each condition.
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).
Time frame: 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).
Time frame: 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).
Time frame: 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.
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