HEART RATE BALANCING FOR MULTIPLAYER EXERGAMES by Tadeusz B. Stach A thesis submitted to the Department of Computing In conformity with the requirements for the degree of Doctor of Philosophy Queen’s University Kingston, Ontario, Canada (September, 2012) Copyright ©Tadeusz B. Stach, 2012 Abstract Exergames combine physical activity and entertainment in an effort to increase people’s motivation to exercise. Multiplayer exergames attempt to include the motivating aspects of group activity by allowing two or more people to play together. In most multiplayer exergames, a player’s in-game performance is limited by her physical abilities. Less fit players are demotivated by repeated losses to more fit opponents, while fitter players face a lack of competition from unfit opponents. This situation makes it difficult for people of disparate physical abilities to play exergames together. This research presents heart rate balancing, a novel player balancing technique to better support engaging experiences in multiplayer exergames. Heart rate balancing bases players’ in- game performance on their effort relative to fitness level rather than their raw power. More specifically, heart rate monitoring is used to set in-game performance based on how closely a person adheres to her target heart rate. Experiments with heart rate balancing show that the technique improves competition between players. A strong correlation was found between people’s perceived effort and their in-game performance with heart rate balancing. The degree to which players noticed the balancing mechanism varied depending on game type. However, heart rate balancing did not interfere with people’s ability to play exergames. These results indicate that the heart rate balancing technique is a promising approach for improving enjoyment and engagement in multiplayer exergames. ii Acknowledgements I would like to thank my supervisor Dr. Nicholas Graham for his years of support and guidance. I am privileged to have worked with him during the course of this research. He has been an excellent mentor and a source of inspiration. Thank you for your optimism, patience, and friendship. Thank you to the people who provided valuable insight on my research. This includes my committee members Dr. Randy Ellis and Dr. Niko Troje, as well as the expertise of Dr. Ryan Rhodes and Dr. Darren Warburton. Many thanks to all the members of the EQUIS lab: David, Rob, Chris, Jeff, Eric, Joey, Jason, Cheryl, Hamilton, Ameer, Banani, Max, Murnal, Zi and all the summer and exchange students. It has been a pleasure to work and play with you over the years. I would also like to thank everyone from the School of Computing. In particular, Scott Grant for the wisdom and humor, and David Holman and Andreas Hollatz for all the food and philosophy. Thank you to my friends and family for your encouragement. My life as a student has been a wonderful experience because of all the amazing people I have met. A special thanks to Samantha for her understanding and caring. Finally, I am forever grateful for the love and unwavering support of my parents Helen and Ben. Without both of them none of this would have been possible. iii Statement of Originality I hereby certify that all of the work described within this thesis is the original work of the author. Any published (or unpublished) ideas and/or techniques from the work of others are fully acknowledged in accordance with the standard referencing practices. Tadeusz Stach September, 2012 iv Table of Contents Abstract ............................................................................................................................................ ii Acknowledgements ......................................................................................................................... iii Statement of Originality .................................................................................................................. iv Chapter 1 Introduction ..................................................................................................................... 1 1.1 Motivation .............................................................................................................................. 2 1.2 Problem .................................................................................................................................. 3 1.3 Solution .................................................................................................................................. 5 1.3.1 Hypotheses ...................................................................................................................... 5 1.4 Steps in the Solution .............................................................................................................. 6 1.5 Evaluation .............................................................................................................................. 7 1.6 Heart Rate Feedback in Games .............................................................................................. 7 1.7 Contributions ......................................................................................................................... 8 1.8 Thesis Outline ........................................................................................................................ 9 Chapter 2 Multiplayer Exergames ................................................................................................. 11 2.1 Exergames ............................................................................................................................ 11 2.2 Group Exercise..................................................................................................................... 17 2.3 Supporting Physical Activity in Multiplayer Exergames ..................................................... 19 2.3.1 Aerobic Activity ............................................................................................................ 19 2.3.2 Strength and Flexibility ................................................................................................. 21 2.4 Spatial Setup of Multiplayer Exergames ............................................................................. 22 2.4.1 Co-Located .................................................................................................................... 22 2.4.2 Distributed..................................................................................................................... 24 2.5 Temporal Setup of Multiplayer Exergames ......................................................................... 27 2.5.1 Synchronous .................................................................................................................. 27 2.5.2 Asynchronous ............................................................................................................... 28 2.6 Player Interaction in Multiplayer Exergames ...................................................................... 29 2.6.1 Cooperation ................................................................................................................... 30 2.6.2 Competition................................................................................................................... 33 2.7 Summary .............................................................................................................................. 36 Chapter 3 Balancing Skill and Ability ........................................................................................... 37 3.1 Static Player Balancing Techniques ..................................................................................... 38 3.2 Dynamic Player Balancing Techniques ............................................................................... 39 v 3.3 Metrics for Evaluating Player Balancing in Exergames ...................................................... 41 3.3.1 Balance .......................................................................................................................... 42 3.3.2 Enjoyment ..................................................................................................................... 43 3.3.3 Transparency ................................................................................................................. 43 3.3.4 Exploitability ................................................................................................................. 44 3.3.5 Portability ...................................................................................................................... 45 3.4 Summary .............................................................................................................................. 45 Chapter 4 Heart Rate Balancing .................................................................................................... 47 4.1 Heart Rate Behaviour ........................................................................................................... 48 4.1.1 Amplitude Problem ....................................................................................................... 49 4.1.2 Quick Start Problem ...................................................................................................... 51 4.1.3 Latency Problem ........................................................................................................... 52 4.1.4 Summary of Problems ..................................................................................................