In 1994, exercise equipment maker Life Fitness partnered with Nintendo on the Life Fitness Exertainment System with games designed for the Exertainment bike. Above is a promotional video for this short-lived product.
The footage shows how the system works and also alludes to Tetris and Pac-Man being made for the system as footage was even shown, but the only games to come out for the system were Mountain Bike Rally and Mountain Bike Rally/Speed Racer combo for the Lifecyle 9XS gym version.
And here's a description of the the Exertainment System Mountain Bike Rally/Speed Racer cartridge that now sells for more than $1300 on the collector market:
Welcome To The Exertainment System Game Pak! In this one Game Pak you can select from three exciting game titles: Program Manager Your Very Own On-Screen Trainer! Life Fitness Program Manager is your electronic personal trainer. It sets your personal workout goals and retains personal workout information for up to four members of your family. Program Manager is perfect for motivating you to get in shape and for tracking workouts - all while you're having fun on the Exertainment system! Mountain Bike Rally Wow! What a ride! Hop on your Lifecycle trainer and race against riders bent on winning at all costs. Watch out for punches and strike back at those cycling foes. But keep one eye on road obstacles. They're at every turn. Quick, choose the ramp routes and leave your opponent in the dust! Speed Racer Ladies and Gentlemen, Start Your Engines. As Speed Racer, you'll drive the fastest, most advanced car in the world, the Mach V. You'll reach speeds beyond 200 mph while competing in six grueling race courses. Off track, you'll find yourself in exotic locations like the Streets of Cairo and the Temple of Kopetopek. It's fast fun for everyone. Go, Speed Racer, go!