Tiredness - A Basket of Goods (bads?)

Hey Guys,

Just reading Scotts tiredness post and a few things came to mind. Whereas any one of these alone might not make us feel tired, what if some of us have any combination of the following, wouldn't it cause a sheeitey feeling? (no offense to the Shia):

1. Lower heart rate from fitness

2. Borderline low blood pressure

3. Lower carb/ calorie intake

4. Low grade depression

5. Borderline iron levels

For example, I have heard that athletic types,  with naturally low resting heart rates, tend to nod off when sitting in one place too long say in a meeting or lecture (famous pioneer triathlete, Larry Scott for one). So wondering, if a person has spent a lifetime "adapting" to a normal or high heart rate, blood pressure or any other bodily condition... - THEN -  that condition changes over a brief period of a couple years, if that person might experience tiredness, lethargy, etc.?

Then, you combine with any one or more of the above.

Solutions? For me, protein powder is a pickup, as well as 20 minutes of exercise here and there. Then, there's anything in my day that might create nervous energy or adrenaline. In my world, that's classes with picky (but easily charmed) 18-20 year old women. 

Best Wishes,

Dave