ADHD stimulant question... PLEASE ANSWER?

I am on Vyvanse (grr) and it dehydrates me terribly which in turn dilates my pupils. I've been drinking copious amounts of water and some gatorade but I always need more!
Why do these things happen?
What's the best way to deal with them?
And will my body get used to the stimulant's dehydrating effect?
I run and exercise a lot so I can't afford to be dehydrated.
Will the meds get in the way of exercising?

Thank you
Best answer 10 pts. for sure!!

Yeah I don't really like being medication but I'm 16 and have no control over that for two years... I'm on 50mg, I have been keeping a daily log, and I think I'll talk to my Dr. about lowering in to 40mg.

Im also on the same medication, and i have not had the same effects as you but I have lost my appitite and have lost a lot of weight. They happen because your body is getting used to the medication. As a result your body acts differently than what it used to before you started taking it. As soon as your mind and body get used to it then everything SHOULD go back to normal. I would just keep doing what you are doing and keep drinking A LOT of water. And it shouldn't get in the way of exercising just make sure you stay hydrated because that would be...well...bad if you didn't! lol
But i hope this helped you! :)

dosage? talk to your dr. and make sure he or she is listening. Ask if you need a lower dose, a different med? Don't be afraid to try different meds. I would talk to the doc though because the med sounds like it is doing more harm then good.

The medication may need some fine tuning in the amounts you are given, record all your symptoms for your next check up and express your concerns with your doctor, He/She may find it necessary to adjust your doseage to rectify this situation, they may even try a different medication. Many times our kids are over diagnosed with ADHD and ADD, some cases are real but many come down to lack of sleep and poor self control, discipline and diet, all of these factors are relevant and can help to control your symtoms and situation, I have a step son who is Diagnosed ADHD and it often amuses me when I see him throw a fit because he doesnt get his own way, I believe it is just poor self control, he can sit still for hours playing a video game (unmedicated) a number of respected leading physicians around the world have used axamples such as this to prove that ADHD is over diagnosed, as the H in ADHD stands for Hyperactivity, and anyone who can sit still for extended periods obviously has no issue with Hyperactivity, more often it comes down to the child having a tantrum because they dont get their own way. ADD and ADHD where virtually unheard of 30 years ago, and there were few if any people running about displaying the syptoms of this now epidemic proportion illness.