Introduction

    Many college aged people have shown a recent increase in the use of dietary pre workout substances in order to improve their physical results and/or their focus in the weight room. There are a variety of supplements that can be used in order to achieve this, but one particular one is used when working out in the gym, and it is known as a pre-workout supplement. Pre-workout supplement is advertised as a product that will increase motivation and performance throughout a workout (Dieter 2015). 
   There are several different ingredients that are in pre-workout that may help to support the claim made by C4. Crowley & Spradley 2012 talked about four main ingredients; L-arginine, caffeine, beta-alanine, and branched-chain amino acids. Beta-alanine and caffeine showed improvement in training purposes on their own whereas the others did not. Beta-alanine is what leads to a harmless tingling sensation in the body by the user. This happens because beta-alanine is a non-essential amino acid, that produces carnosine. Carnosine is stored in your skeletal muscles and it reduces lactic acid accumulation when working out, and therefore reduces fatigue (Schinetsky 2018). Creatine along with beta-alanine is also believed to delay the onset of neuromuscular fatigue as well (Crowley and Spradley 2012). This is why beta-alanine is an important element to pre-workout. Caffeine was also found to show improvement, because it blocks adenosine receptors. The blocking of these receptors stops the action at these receptors, and decreases the perception of pain and effort leading to improved exercise (Crowley & Spradley 2012). 
      One study that tested the effects of pre-workout was conducted by Jagim et. al, (2016) that tested muscle endurance for both upper and lower body muscles. This was done by testing a single set until failure occurred for both bench press and back squat. Between two groups the result found was that individuals who were given a multi-ingredient pre-workout supplement (MIPS) had more repetitions until failure than those given a placebo (Outlaw et. al, 2014).  Unlike many tests however, this study also tested the mean power output and energy increase from MIPSs through the use of an anaerobic sprint test. The sprint test concluded that mean power was improved (Outlaw et. al, 2014). 
   Another factor that is a considerable part of taking pre-workout supplements is the time that is considered "pre" workout. Studies testing pre-workout state that the latency period, in which subjects should endure after taking the supplement and before starting physical activity, is 25 minutes(Crowley and Spradley, 2012) and (Gonzalez, 2011). 
    The goal of this study was to take this advertising quote and test the effectiveness of the product it is describing. In order to do so we tested reaction time, which could be affected because with increased focus and intensity, a faster reaction time may be seen. An increase in energy, along with a decrease in pain and fatigue may help subjects focus. The testing of reaction time to auditory and visual stimuli is how we plan to see a change in focus and subsequently a faster reaction time. We also plan to test the claim that muscle fatigue is decreased while using this product. A dynamometer was used in order to test this by analyzing maximum grip strength, and the results were used to see any reduction in muscle fatigue while performing the task. In order to test power, using a consistent weight, the subject held the dumbbell in a set position down by their side with their arm bent at 90 degrees, until unable to do so. Using electromyography, the activation of the bicep was recorded. This was performed with and without pre-workout. The time until failure and the power output were recorded and analyzed. 

Methods

Study population

    The population to be studied was picked based on a questionnaire in order to find people who are physically active at least 5 days a week, do not take pre-workout, and what physical activity specifically the subjects do. The subjects needed to be active in some way, sports or any physical activity such as dancing, swimming, running, etc. for at least 5 days a week. The subjects were also those who were active but did not use pre-workout supplement, or have not used the supplement in over a month. The overall description of these individuals was either male or female who are active consistently and do not normally take pre-workout.  
    The reason we chose kids who were already active was because we wanted people who consistently work their bodies physically. This was important to us because we believed these people would perform the tasks to the fullest of their abilities and would be more disciplined. We chose people who didn't take pre-workout because we believed that there would be a greater impact on somebody not used to the supplement being taken. 
    The pre-workout used will be C4 Sport by Cellucor, and the serving size will be 1 scoop, which is 11 cubic centimeters. It will be mixed into 6 oz. of water, and again drank 25 minutes before performing the tasks. The patients will drink the entire drink mix in one continuous "gulp" while sitting, and will remain seated until beginning the tasks once again. In order to make sure the entire supplement is taken, 5 ounces of water will be mixed with the 11 cubic centimeters of pre-workout, and then the last ounce will be used to wash the rest of the supplement out of the bottle. This will be done to ensure that all of the supplement is taken. 

Procedure 1: Reaction to Visual Stimulus

    For this test, the subject was to press the red button switch as soon as the finger sensor transducer was pressed by the group member conducting the experiment. The difference in time between the pressing of the sensor by the instructor, and the pressing of the red button by the subject was recorded as their reaction time. The visual cue for the experiment was the pressing of the motion sensor by the instructor. The subjects would first be put through a baseline test to determine their reaction times without any supplement being consumed. The test consisted of 6 stimuli in random succession of 1 to 10 seconds. The reaction times for each of the 6 stimuli were calculated and then averaged for each subjects. The subjects were then given a serving of the pre-workout supplement and were allowed a 25 minute latency period for the digestion of the supplement. The same test was then conducted again using different 1-10 second successions for each stimulus. 
Analysis:
    The reaction times were calculated and then averaged. The average for both workout tests and non pre-workout tests were calculated and a standard deviation was calculated between them. The averages were graphed and then analyzed using a one-way ANOVA test.

Procedure 2: Reaction Time to Auditory Stimulus

    Subjects in this test were told to press the red push button when the sound was heard out of the computer. The tone was a clear loud sound developed from the computer through a macro connected to LabChart software. A baseline was first conducted, the subject was presented with 6 auditory cues with a succession of 1 to 10 seconds randomly. The reaction times were calculated and averaged the same as in the first procedure. The subjects were then presented with the pre-workout, given a 25 minute latency period. After this the same test was conducted. 
Analysis:
    The reaction times were averaged. For each category the reaction times were averaged and then a standard deviation was also calculated. The data was then graphed and compared and to determine the statistical significance of the data a one-way ANOVA was conducted

Procedure 3: Muscle Fatigue

    Subjects were tested on muscle fatigue using the dynamometer. First a baseline is conducted to determine the maximum grip strength in the subject without any supplement. The subject is then instructed to squeeze the dynamometer as hard as they can for 10 seconds with a brief half second relaxation period 5 times. The apex of each peak was measured as well as the lowest point, the mean value was then calculated for each of the 5 periods. The subject was then given a supplement of pre workout and given a 25 minute latency period where they are allowed to recover from the previous test and allow the pre workout to be digested. The baseline for each subject was then calculated again. The test was conducted again with the same steps and the same calculations. 
Analysis:
    The standard deviation for each subject was then found by comparing the averages of the 5 tests with pre-workout and without pre-workout.

Procedure 4 : Electromyography 

    Another test that was conducted was through the use of electromyography. The subject was sat in a comfortable position and asked to keep their arm bent down by their side at a 90 degree angle. The subject was then given a 15 pound dumbbell and asked to hold the weight in this position until unable to do so. After failure the subject was then given the pre-workout supplement. The subject followed the protocol stated previously on how to take the supplement. After 25 minutes, the test was then performed again. The results were then collected.
Analysis:
    A spectral analysis was conducted on the EMG of the biceps. The shift in frequency and the s was analyzed for the subjects baseline trial and pre-workout trial. During each trial, the spectral analysis of the first 10 seconds and the last 10 seconds were graphed. The first 10 seconds was non-fatigue, and the last 10 seconds was fatigue. The EMG signal is transferred through a fast foyer transform, and then the power spectrum between samples was compared. Also, the time the weight was able to be held until failure was recorded and compared between each subjects baseline trial and pre-workout trial. 

Protocol

Statistical analysis

Results

Reaction Time to Visual Stimulus 

Reaction Time to Auditory Stimulus 

Muscle Fatigue

Electromyography  

Discussion