When you think of working out, you probably imagine running and lifting weights. However, there are exercises that can be done with almost no real movement at all. These are called isometric exercises, and the point is to not change the angle of your joints, or the length of the muscle. This is supposed to produce results, without causing as much strain as typical dynamic exercises.

One of the troubles with isometrics is that you don’t always have a good measure of what you’re accomplishing. However, this Grip Isometric Exercise Trainer will show you exactly how much force is being exerted when you push or pull on it. You can measure up to 200lbs of force with this $60 gadget. Sadly, it looks as though it’s only good for upper body workouts, as it doesn’t have any way to accommodate your feet.