Exercising is all about finding motivation. This custom bicycle stand you can build at home will let you watch TV while you work out, but only if you keep pedalling.
You've probably seen a bicycle set up to provide power before, but this project from Instructables user plays in traffic does something different. Instead of providing or cutting off power, this setup merely cuts the signal to the TV after 10 seconds of no pedalling. Resume pedalling, and the signal is restored. There's even a warning buzzer that warns you before the signal is going to cut off.
The build uses a bicycle, a bike stand, an Arduino Nano, and a few other simple components, but its construction is fairly simple. Once you have it all put together, the only way you can watch TV is if you work for it. It's a great way to motivate your exercise and be entertained at the same time. You can see a simple video of it in action here.
No TV unless you exercise! [Instructables]