Feel the Disney Burn...

Anyone who has visited Walt Disney World will recount the seemingly endless hours of walking and standing in lines and insufficient sitting and relaxing. So, how much walking, standing, and sitting occurs during a typical day with the Mouse? Each of the three subjects in this experiment wore the USB Accelerometer for the entire day while at the parks. The USB Accelerometer was configured to constantly collect data at 16 hertz. This provided a tremendous amount of data that permitted analysis of activity level throughout the day. Here, the activities during the second day of Subject 'A' are presented.

Distance Walked

A simple analysis of the data provides the number of steps taken during the day, similar to a pedometer. Walking generates a very repeatable, cyclic motion in the vertical axis that creates a consistent impact peak. Searching the x-axis data for events that exceed a certain threshold resulted in the number of step events. Since USB Accelerometer also provides precise time stamp for each step event, the events were filtered to remove any sequence that fell outside a normal walking pace. The filter was based on a histogram of the step events. For example, steps quicker than 0.4 seconds or slower than 1.1 seconds do not correspond to actual walking. Based on this analysis, Subject A walked 21,510 steps for a distance of approximately 9 miles (given a 2.2 ft stride).

However, a walking pace of 1.1 seconds per step was unusually slow and was probably not actual walking. Such a slow pace was likely a step event that occured while standing in line and therefore wasn't a 2.2ft stride. Reviewing previous walking data unrelated to this WDW data, a typical walking pace for Subject A normally ranged between 0.6 to 0.8 seconds per step. Filtering the WDW data again with a tighter pace window resulted in 16,785 steps, or about 7 miles. The 7 mile approximation is probably a better estimate of actual walking distance during that day.

Walking StepsStep Histogram

 

Daily Activity

The second day of the trip was especially long and gruelling. An early start at the Animal Kingdom and late finish at Epcot made for an unbelievable 12 hour day of "fun". How much time was spent walking, standing, and sitting? Was there any rest? Taking the data of Day 2, an analysis provided an abstract level of effort expended throughout the day.

The analysis started with a Fast Fourier Transform of the xyz RMS acceleration. The FFT created a frequency spectrum that was then filtered to the frequency region of human activity. This filtered spectrum was then summed and plotted against time to represent a level of effort exerted by Subject A throughout Day 2.

The plot below illustrates the 5-minute moving average of the calculated effort level. Comparing the effort level to a log of events revealed a correlation to particular types of activity. Sitting, standing, and walking became distinct levels of effort in the plot. Periods of "Sitting" included resting on a park bench, watching a show or movie, and eating a meal. "Standing" included waiting in line for an attraction, moderate activity during a ride, and driving in a car. "Walking" included casual to brisk walking and participation in intense rides. Catagorizing the effort level into one of the three types of activity resulted in 22% sitting, 31% standing, and 47% walking during Day 2. The effects caused by spending 78% of a 12 hour day on your feet is referred to as the "Disney Burn".

Effort Level Day 2

 

A
Standing in line and subsequent ride on the intense Expedition Everest roller coaster
B
Walked directly onto the motion intense Dinosaur ride (no line)
C
Returned to Expedition Everest for another round
D
Sat and watched stage performance of the Festival of the Lion King
E
Ate lunch at Downtown Disney shopping area
F
Combination of sitting and standing while visiting with friends
G
Drove from Downtown Disney to Epcot
H
Slow moving Spaceship Earth ride
I
Slow moving ride at Norway
J
Sat on bench and rested
K
Stand/Sit while watching 360° movie
L
Sat for a quick dinner
M
Stood and watched fireworks
N
Walked back to car

Back to Part I: Zip-a-Dee Do Da

Back to the Introduction

Read about more about the USB Accelerometer applied to actigraphy.