Employers who are hiring want "energy," so those want to be hired have to have and demonstrate "energy."
To which I say: If you want "energy," hire a two-year-old.
I have recent experience with someone described to me by several people as "having lots of energy." In some ways I am the best judge of character I know, and it's easy for me to see that what is perceived as "lots of energy" is no more than a spectrum of annoying nervous tics and a tendency to look rushed for no particular reason.
I worked with a woman who also was perceived as being "energetic" because she literally ran around constantly to display her "sense of urgency" and "can do" attitude. Not surprisingly, she accomplished about half as much as someone who simply sits down and gets work done.
Like I said, if you want "energy," hire a two-year-old. Except for the occasional nap time, "energy" is never in short supply for them.
What employers really want, I think, is initiative—the ability to take charge, to come up with ideas, and to find problems and their solutions, all without having to be managed too closely. A person with initiative just does it. A qualified, experienced person with initiative just does it well.
Humans are visual creatures, however. Initiative is hard to see, while "energy" is hard to miss. Someone with initiative could quietly generate dozens of ideas and solutions, and he would be thought of as a dedicated hard worker, perhaps even a smart one. If the same person did half as much but with "energy," and threw in a little self-promotion, he would soon be on the management, even executive, track. And he would want to recruit "high-energy" candidates like himself—nervous tics and all.
Meanwhile, the real work is done by others, those who focus on the doing, not the talking.
I wonder if that is why I sometimes feel like many organizations are run by the equivalent of two-year-olds—complete with "energy," egos, and tics, but not so complete in the areas of, say, intelligent decision making or action. Even the thoughtful have been conditioned to think that "energy" is a must.
"Energy" in a two-year-old is both exciting and exhausting. "Energy" in an adult is primarily exhausting. If I want "energy," I'll go to a playground. If I want vision, ideas, and accomplishments, I'll seek out an adult.
Unfortunately, I'm not hiring.