“Am I not being considered for that job because I’m too old?”

Clients have whispered that question to me many times, afraid they’re washed up and unappreciated in the workplace, that no employer will want them as they move from mid- to senior-level positions. It’s a natural question, and when the economy is ailing and the job market is as tight as it has been, too many out-of-work older professionals begin to doubt their own value and even blame themselves for circumstances beyond their control.

At a time when baby-boomers are nearing what are supposed to be their golden years, more and more older Americans are finding that they need to work longer to rebuild their recession-eroded retirement savings. Older Americans’ increased labor force participation will challenge all of us to find new and earnest ways to bridge the generation gap between our older and younger colleagues.

For older workers who do become unemployed, trying to reenter the labor force has been more difficult than it has been for their younger counterparts, with workers between the ages of 55 and 64 spending an average of 44.6 weeks on unemployment (through October 2010) — almost 11 weeks longer than workers age 25 to 34, and 17 weeks longer than those 20 to 24. With the overall employment rate inching down to just below 9 percent, and 4.4 job seekers for every job opening, the situation is already tough enough, without doubting yourself because of your age.

In our consumer culture, we too often value packaging over substance. In response to questions about age, I always tell my clients: what you think about, you bring about. Consider that the image you have of yourself may well be incongruous with the way others see you.

Many of us spend our entire lives believing we’re either “too old” or “too young.” To me,old is a concept, a state of mind. Age and appearance have nothing to do with being old. Unfortunately, in the workplace when one person characterizes another person as old,  he or she too often means that a person has low energy, is unwilling to learn or try new things, or that he or she is stuck in the past. In reality, however, those descriptors could apply to anyone — regardless of age.

By age 40 — the age at which you can legally be considered a victim of age discrimination — you’re probably working in a management position and ready to take on more tasks and responsibilities. For some at this stage of their careers, the ego is in high gear as they conquer the world, slaying dragons in the office and fighting the good fight. Others return to school for advanced degrees, seeking the coveted titles that will give them added respect and credibility.

But for other 40-somethings and older professionals who have been laid off, passed over or desperately wanting to find another job, self-doubt can creep in and wreak its special brand of havoc. As bellies grow soft and grey hairs start to appear, external packaging becomes an area of concern that can compound a growing internal sense of self-doubt

Never let grey hair or an expanding waistline trick you into becoming a self saboteur. Fight off self doubt at every turn — it has no place in a job hunt or the workplace. Believing you’re too old — or even too young — is a way of holding onto every false belief you’ve ever had about yourself. Furthermore, hanging on to these beliefs will not serve you in finding or keeping your job.

If you’re feeling old, set aside some time for exercise and other tried-and-true ways of maintaining a healthy and youthful outlook. Eat a healthy diet. Get plenty of rest. Read everything you can get your hands on to keep up on current events. Keep yourself up to date on current technology trends. If you haven’t already done so, sign up for a Facebook account and follow some of your favorite subject matter experts on Twitter. Age happens — it’s how you deal with it that will determine how your colleagues look at you (and just as importantly, how you look at yourself). If you’re young at heart and an energetic, productive member of the team, no one can ever say you’re “over the hill.