It certainly sounds like you have MG (the "good" response to the Mestinon is almost always a dead giveaway).

When you are one of those who has been diagnosed based on a droopy eyelid as the first symptom, you need to know that the MG will probably progress over the next 1-2 years; fortunately, when it is caught early, you are able to pay closer attention to what is happening and address any issues you may have right away.

You may very well find that it will become harder to continue with marathons and triathlons. Our bodies do "betray" us with this disease.

Definitely continue as long as you feel you are able to, but PLEASE exercise caution when doing so - the muscles that allow our lungs to expand and contract are affected by MG, and if they run out of Acetylcholine, THEY WILL CEASE TO FUNCTION. If that happens, you will not be able to get oxygen from your lungs to your brain and you will die without immediate mechanical ventilation.

I'm not trying to scare you. (Really!)

This is a reality that all of us have to face with this disease. We have to be extra careful to listen to the signals that our body is sending us. If we start to feel tired, we MUST rest. It sucks, but the alternative sucks even more.....

If I could offer a suggestion: Stop the triathlons immediately. If your body gives up on you during the swimming portion of the triathlon, I'm not sure that the medical team could get to you in time to save your life. (Even swimming pools are a dicey situation for people with MG - it is imperative that we have someone paying attention to us at all times to prevent possible drowning)

I'm guessing that your parents are still alive - don't put them in a situation where they may have to bury their beloved son. (I say that as a daughter who had to watch her parents go through that when my sister unexpectedly passed away - if you can take steps to prevent that from happening, DO)

I know that this may sound harsh, and I apologize. We all have to adjust our way of life, depending on how our bodies react to this disease. Some people have a more mild case than others, but we never know who is going to have a severe presentation and who will be just mildly inconvenienced by it.

All of us pray for the best, but prepare for the worst - it's all you can do.

Over time, you will make peace with your body, but it's going to take time. There will be good days and bad. You will rail against the hand that you have been dealt, but then you will find yourself looking at other people who find themselves in a much worse situation, and you will realize that you CAN deal with this.

This is a GREAT group of folks - they've pulled me through on the days when I was feeling sorry for myself, and they've been an invaluable source of information. We're all here to help you get through this!