Theres a lot of b/s information on the internet, and I'm just wondering if any of this is true.
If you google "spinal decompression", many sources tell of incidents where a person will temporarily gain anywhere from a 1/2 inch to 2 inches of height due to spinal decompression. Astronauts in space have cited this phenomenon, claiming 2 inches in temporary increased height due to the lack of gravity compressing their spine. This supposedly also occures when sleeping in a bed overnight due to the decompression caused by laying on your back, and that many people experience an inch or two of "morning height" when they wake up, which is usually gone by the end of the day due to pressure put on the spine during the day from gravity and every day "wear and tear" on the body such as heavy lifting.
The theory is that if you are a healthy, physically active person (such as an athelete) and you practive spinal decompression EVERY day for 20 minutes or so using a "door gym" (one of those exercise bars installed in a door way) to hang upside down to let the effects of gravity decompress your spine, you can train your spine to become stronger and thus resist the effects of gravity and heavy lifting on your spine, making the "morning height" slightly more permanent. If you stop the exercises of course the effects will deteriorate rapidly, so you have to do it every day religiously.
It sounds like it makes sense, but I wanted to get the advice of a medical professional to be certain.