Methods

Twelve participants will be participating in this study; chosen from all different backgrounds with varying levels of athleticism and participation in athletic activities. All the participants were informed that they need to create a playlist of music that they considered to be motivation, but otherwise performed the experiment primarily blind as to not create a bias. The chosen participants came into the laboratory twice to fulfill the experiment, one day they completed the tasks without music and the second time they used a playlist of self-selected music. The participants were selected at random to perform the tests with music on the first day, and some were asked to perform the tasks with no music on the first day in order to keep other confounding variables out of the experiment. Three participants would serve as the control group and would perform all of the experiments twice with no music either time. In order to eliminate the confound of previous muscular fatigue or delayed-onset muscle soreness, the subjects came in 4 days apart from each experiment. The participation pool was not limited by gender or age, in order to record a more representative pool of data regarding the impact of music upon muscular fatigue across all categories. Unfortunately, the sample size was limited due to a lack of time.
    Heart rate can easily be measured on the ECG, but heart rate variability was a separate metric that had to be extracted from the ECG readings and is a good indicator of the autonomic nervous system's balancing act of the sympathetic and parasympathetic branch activation. The method of analyzing heart rate variability used was the time-domain method called RMSSD (Root Mean Squared of Successive Differences) between each heartbeat. The basis of calculating the RMSSD is by measuring consecutive “RR intervals”, or the time intervals in milliseconds between the R peaks of the QRS complexes. The RMSSD is a reliable measure of heart rate variability and parasympathetic branch activation, as activation of the parasympathetic branch will decrease heart rate and increased heart rate variability.
Data from the EMG recording was processed using the root mean square method, which is used to analyze the raw EMG signal of isometric voluntary muscle contraction. Ultimately, this method greatly smooths out individual spikes seen in the EMG recording and allows for much more clear indication of change in activity of the muscle over time.
Procedure 1: ECG Recording (heart rate variability) -
The participant was prepared for ECG, and the recording was taken as outlined in the protocol for laboratory experiment #5. The volunteer should be instructed to relax for a minute while not listening to music, and their ECG trace will be recorded. When the volunteer returns four days later for the second half of the experiment they will again be instructed to relax, but instead will be allowed to listen to their music of choice for a minute before recording and then for the minute of recording. The particular phenomenon of interest for this recording would be heart rate variability. Heart rate variability is defined as the time interval between beats. Heart rate would also be calculated for the music and non-music group, which is done by counting the number of QRS complexes in a 15 second period, and multiplying this number by four.
Procedure 1: ECG Recording (heart rate variability) -
The participant was prepared for ECG, and the recording was taken as outlined in the protocol for laboratory experiment #5. The volunteer should be instructed to relax for a minute while not listening to music, and their ECG trace will be recorded. When the volunteer returns four days later for the second half of the experiment they will again be instructed to relax, but instead will be allowed to listen to their music of choice for a minute before recording and then for the minute of recording. The particular phenomenon of interest for this recording would be heart rate variability. Heart rate variability is defined as the time interval between beats. Heart rate would also be calculated for the music and non-music group, which is done by counting the number of QRS complexes in a 15 second period, and multiplying this number by four.
Procedure 2: Goniometer -
The participant was prepared to use the goniometer, and the recording was taken as outlined in the protocol for laboratory experiment #2. The goniometer was placed over the elbow joint. In this exercise, the volunteer is asked to perform a bicep curl. Prior to data collection, a baseline angle should be obtained by having the subject complete a partial bicep contraction, maintaining a 90 degree angle between the forearm/arm. The researcher will time the individual (in seconds) under exposure to music/no music to see how long the subject can sustain the position of a 90 degree bicep curl contraction. The subject will be timed until there is a 10-degree difference in forearm/arm angle orientation while using a 5-10 pound dumbbell to offer resistance.
Procedure 3: Hand Dynamometer -
Volunteer picks up and loosely grips hand dynamometer in a fist of the dominant hand. The subject is exposed to the music for a minute of their choice prior to beginning the exercise and then volunteers will be asked to grip the dynamometer at maximum strength for 3 seconds in order to get a 100% baseline.The subject is then instructed to grip the dynamometer for 30 seconds at 60, 80 and 100% maximal grip strength. (If a volunteer is not instructed to listen to music prior to running experiment, then they will simply perform the trial accordingly). We will record the time they are able to stay within a 4% range (as indicated in lab protocol 3) of the intended percentage of the maximal grip strength. Subjects that are listening to self-selected music for this trial will be listening to music for this period. The maximum force of grip strength, as well as the duration of maximum, will be averaged between the control and experimental groups.
Procedure 4: EMG -
Volunteer was prepared for EMG, and the reading was taken as outlined in the protocol used in laboratory experiment #4. Now the volunteer should face away from the monitor and be instructed to hold a bucket filled with water. The starting amount of water should be 1/2 of a gallon, weighing 4 pounds. After 30 seconds of holding the bucket more water will be added, doubling the weight of the bucket. Again after another 30 seconds of holding the bucket more water will be added, tripling the initial amount of water in the bucket. Data should be recorded throughout the whole time. When the volunteer returns again they will be instructed to listen to the songs of their choosing and the same process of adding water to the bucket over increments of time can be repeated. Data was further analyzed and represented graphically.

Statistical analysis

Results

Effects of music on Amplitude of Hand Grip Strength (Hand dynamometer)

Effects of music on Heart Rate (ECG)

Effects of music on Angle Sustenance under Weighted Bicep Curl (Goniometer)

Effects of music on Amplitude of Muscle Contraction (EMG)