The most intractable of my hypothyroidism symptoms is lack of energy. I actually was unaware of this until very recently!
Weird, but explainable. I thought i had a willpower or motivational problem, or a tendency to laziness, and so did most people around me -- i could tell, though they were too kind or tactful to actually accuse me. Truth is, i always COULD pry myself from the couch if i HAD to, or wanted to badly enough, and when i'm in action ... i trust i'm not being immodest in saying that i'm GOOD. I'm just not good OFTEN ENOUGH to be a big success in the world.
But the close observation that i've given my health over the past year has opened my eyes to a few things. Wooo's discussion of her childhood was a big help, too. People with "normal" metabolisms have a well-spring of energy that isn't available to all of us, and the seed seems to have been sown in our prenatal environment, or at least in early childhood.
My best friend, M, is only about four months younger than i am, so the age factor is immaterial -- we met in our seventh-grade music class and have been dear to each other ever since; she's the person i've known longest, outside my family. Our natures harmonize together though we're outwardly different in many ways, especially in appearance. I'm short and stocky, and she's leggy and lean. I tease her about being an overachiever, but she's actually just an EXCELLENT achiever of whom i'm jealous because of her abounding energy (and other qualities which are not relevant here). K is another dear friend of us both, and she's very like M -- the amount of work she can accomplish in a short time is phenomenal. My husband J is another one of these workers.
When i'm out and about in the world with any one of them, trying to keep up, i go home at the end of the outing absolutely EXHAUSTED. If J gets me up early to go out for breakfast and run errands all morning, that's it -- i'm done for the day! We return home, i take a beverage to my chair, sit down with a book or my computer, and spend the ensuing hours marshaling my vitality so that the next call on my exertions will actually find me able to answer. In other words -- a moderate amount of energy expenditure is immoderately draining to me ... and probably to a lot of other people, also.
Fitness enthusiasts, professional or otherwise, try to urge us to ignore our instincts and just get up and go for a walk or a run. In some respects, this is good for us as we know that getting some kinds of exercise helps us to create new mitochondria. What they don't understand is that exhausting ourselves in what to "normal" people is nominal exertion, we are draining our scanty resources to the point that OTHER activities (like making a living or taking care of our families) has to pay the price for our exercised-diminished vitality. More mitochondria are GOOD -- but buying them may be too expensive for some of us.
THAT is why i'm on such an obsessive quest to improve vitality through diet, supplementation and lifestyle. Once i improve my baseline energy available for all my everyday uses, i'll have more to spare for the optional ones, which have a potential for enriching my life ... like more exercise.