There's a very obvious limitation to exercise gaming suites such as Wii Fit and Xbox Kinect: You have to work out in your living room. The Goji Play is looking to change that by taking fitness gaming to the gym to make your time on the treadmill, stairclimber, or bike more competitive and fun.

Developed in part by Kai Hung, a co-founder of Guitar Hero, the package includes two small controllers that attach to the handgrips of your preferred cardio machine, and a wireless sensor that clips to your workout shorts. Link these devices to your iPad, iPhone, or iPod through Bluetooth. Simply lay your device in the reading slot on your spin bike and start the game.

Users can develop a profile that tracks fitness goals, counts calories and steps, and for the more competitive, pits friends and families against each other on point-based leaderboards. The third-party games can be downloaded through the App Store, and align with different methods of training. “Riptide GP," for example, is a jet-ski style racing game that incentivizes longer cardio sessions, while “Into the Dead” (our personal favorite), demands multiple full-on anaerobic sprints through fields and forests overrun with zombies.

Throughout the play, intensity of output was surprisingly high, and the hard fitness stats revealed by the Blue Goji tracker were useful in mapping our progress. Admittedly, we had to curb our cries of victory in the spin-bike line. [$99.99; bluegoji.com]