Virtual reality offers the potential to enhance sports and fitness by creating realistic simulations and enhancing the experience of indoor exercise.
Sports simulations can take many forms depending on the purpose of the simulation. Video, computer, and arcade games tend to focus on the strategy of the sport and the "fun" of the competition. Frequently, these types of games offer head-to-head competition between two players and can occasionally involve collaborative teams. Virtual reality concepts are beginning to push the realism of these games by combining three-dimensional design, sound, and high resolution graphics at relatively smooth rendering rates. Typically, these types of game simulations do little to improve a players ability in the actual sport. However, as the realism of telepresence increases, the formation of useful mental strategies could improve performance in the actual sport. Examples include Access Software Corporation's Links386 Pro golf for the IBM PC and Sega Corporation's Outrun 2019 driving simulation for the Sega Genesis NTSC video game system.
A second form of sports simulation involves using virtual reality concepts to physically immerse an individual into competition of a given sport. An example of this is the racquetball simulation implemented through the Autodesk cyberspace system (Pimentel, 1993). In this simulation, the participant uses a special racquet and a head mounted display in order to play a round of virtual racquetball. One might participate in this form of simulated sport to practice for improvement, to develop coordination, to develop a mental understanding of game strategies, to engage in fitness, or just simply to entertain oneself.
Depending on the simulated sport, the impacts of physical and visual immersion can require tactile and/or force feedback. This feedback not only creates realism by compensating for muscular movements or indicating contact with objects, but also is required to keep the virtual world from colliding with the real world possibly causing an injury. Most immersive sport simulations which require tactile feedback are forced to trade reality for some unnatural adjustment to the sport due to the inadequacy of current haptic VR technology. In the Autodesk racquetball simulation example, the physics of the ball trajectory was modified so that the racquetball always returned to the racquet for the next swing, thereby avoiding the problem of how to handle diving or reaching for the ball.
Most competitive sports do not have adequate ways of simulating the necessary tactile or force feedback, making realistic simulations of physical immersion unachievable in the foreseeable future. It is important, however, to realize that some sports have tactile feedback devices already available in the form of fitness simulation machines.
At a typical fitness center, one can choose from an array of exercise machines to use. Examples include the exercise bike, treadmill, cross country ski simulator, stair climbing simulator, and rowing machine. Each of these devices provides force feedback for the purpose of repetitive exercise. Clearly, one can visualize an immersive virtual reality system which increases the pleasure, or decreases the boredom of using these devices by immersing the user in a realistic alternative environment. Such systems indirectly track body movements by monitoring the moving parts on the machine. To many users of repetitive exercise machines, a virtual ride through the Swiss alps would be more enjoyable than a stationary ride through the local gym, and be worth a small increase in cost.
The potential economic benefits of merging sports and virtual reality are lucrative. The exercise bike has already had one commercially successful venture in the VR direction, the LifeCycle, which can be found in most any upscale fitness center. The LifeCycle model 6500 combines a visual display of hilly terrain with adjusted pedaling resistance conforming to the slope of the incline. In addition, a biofeedback sensor monitors heart rate and adjusts pedaling resistance to keep the heartrate in a predetermined range. An example of a more immersive but experimental system is the Autodesk cyberspace system adapted to an exercise bike. The user wears a HMD to generate realistic images while feedback from the cycle wheel speed and handlebar direction guide changes to the visual display (Pimentel, 1993).
A prominent speaker in the world of telepresence recently said "The exercise bike telepresence system has become something of the Holy Grail of this business right now. Everyone is hoping that they can build one that is cheap enough to go into a mail order catalog." (Laurel, 1992).
The problems of virtual environments for sports and fitness are scene complexity, rendering rates, 3-D sound and tactile/force feedback. The recommended study list in addition to a computer science curriculum includes 3-D graphics, rendering algorithms, scene generation, electrical engineering, mechanical engineering, and a basic understanding of physical fitness, anatomy, and sports medicine.
Brenda Laurel. 1992. User Interface Strategies '92.