I bought a pair of Shimano SH-MT33L Mountain Bike Shoes for a spinning class at my local gym. After attaching a pair of SPD cleats I find that it takes great effort to clip in and out...way too much resistance. I tried them on different X-bikes at the gym and same thing. I can clip in and out but its way too tight, to the point that the cleats actually get misaligned. I noticed that the cleats sit below the shoe rubber and are not touching the ground when I walk. I am wondering if the problem may be due to the rubber pressing down against the pedal, creating too much resistance, because the cleats are not exposed enough. Any ideas?

Did the cleats come with shims? If so, put a shim under the cleat or make a sjim out of plastic.

You have no control over the setting of those spin bike pedals. Either bring a hex wrench or just use the other side of the pedal.

You should be able to adjust the tightness of the pedals using an allen (hex) wrench. They may even have one in the spin room, if you don't. I've had to do that before.

As stated above, check the tightness of the pedals first. If you have deteremined that it is at its lowest setting, check the type of cleat you are using. The SM-S51 cleats is a single release mode cleat, wherein, you can only clip out by twisting your ankle outward. The SM-SH52 and SH55/56 is multi-position release and you can clip out by twisting your ankle in any direction.