extreme fatigue after exercising

[Genp]

My blood tests are always normal (at my annuals).
40 year old female. 30 pounds overweight.
My blood pressure is normal to low.
Diagnosed with anxiety 5 years ago GAD (although nobody that knows me can notice it,,, first doctor said I definately did not have anxiety as I was so laid back). Did consult for it and control panic attacks which are now rare. Only get them in calm situation... not when I am stressed out at all.
Nothing very stressful in my life in terms of events, although have a lot on my plate.
Family history of high blood pressure and heart attacks on dad's side.

My doc says he won't do any further testing for my heart as my tests are normal.
Thyroid shows ok on blood tests.

I am trying to exercise (hate it!), but if I just go on the treadmill for 20 minutes at a decent pace, I then feel extremely tired... I need to actually take a nap and cannot keep my eyes open.

My resting heart rate is about 90, so it goes up pretty fast when I exercise but take quite a bit of time to actually slow down afterwards... about 30 minutes it seems.

What is wrong with me?

I do not feel depressed at all... my life is pretty close to exactly what my dream life would be... but I have been feeling like *** for a few years with low energy.

I eat very healthy foods, so my diet is not the issue (just eat too much of it).

Less than 8 hours of sleep means I will be tired next day.

Any tips?

[Genp]

Thanks for your help!!!

[ThyroidHunter]

I am concerned about the combination of easy exhaustion & a resting heart rate of 90?

The normal heart range range is 60-80 in a healthy hearted person at just about any age. A slight overweight issue may increase this, but 10% + over seems high to ignore ALL heart issues on "I won't do any more tests" kind of attitude. Which I would also suggest may be a problem, none of us needs a Doc with an "attitude". We need Docs who won't quit until they find the problem, which sometimes means looking in the same closet for awhile.

You aren't new to the treadmill, (which I use 3-5 times a week). I have never felt so tired from a workout that I had to nap and could not keep my eyes open. I believe you have some medical issues that are not diagnosed.

My best suggestion for the moment, is to find a new General Practice physician, make a list of ALL symptoms, and then see the new Doc to see if a new perspective can help. As you said, your first Doc completely whiffed on the Anxiety diagnosis. Docs are people, they miss things and make mistakes like anybody else. Last time I heard, it was still called the "practice of medicine", because nobody has it perfect.

Hope this helps and Good Luck in the search