If you are really noticing an ammonia smell after riding, definately get some good carbs in your system. And water. The reason water is important for weight loss isn't because it flushes you out (boy I wish I could do the big flush) but it helps the liver metabolize fat. It doesn't mean if you drink 4 gallons of water it will metabolize faster, but if you aren't drinking enough, there are other ways your body will provide energy and sometimes it doesn't involve metabolizing fat.
There is a great book called Our Body's Many Cries for Water which I had to read for a physiology class. You would think that would convince me to drink more water. Also, google 'water metabolism'. Some of the sites are not reliable but many that are written with reference to endocrinology can be trusted. Any book on endocrinology will also talk about it. Really interesting.
Wow, it is so cool to see how well you ladies are doing. Keep up the good work. I still have to lose another 67 pounds myself. I like seeing the one lady who was not afraide to show a picture of herself in kit in her avitar. You rock! I am normally horrified to see how bad I look in that clingy spandex. I have the slight problem of unless I get unnaturally thin I always look kind of fat, so that doesn't help.