Sure, treadmills aren’t exactly on the cutting edge of technology — unless you count the ones with LCD displays, DirecTV, etc., but they are fitness gadgets nonetheless. Continue reading to see the top three things you shouldn’t do on a treadmill.

1. Bike Riding

For those who want the feeling of bike-riding while on a treadmill, we recommend you take a nice long nap before you end up like this guy. Let’s just say smashing his face should be the least of his worries.

2. Handstand

Unless your hands are faster than your feet, we don’t recommend trying to do a handstand while the treadmill is running at max speed. If that’s the case, I hear Cirque du Solei calling your name.

3. Using a Hand Wrench Built Treadmill

Can’t find the wrench needed to put your treadmill together? Well, don’t use your hands to do the job, as everything just may fall apart when demonstrating the device for friends and family.