Even if you love your job, you can still get burned out. That's the message from executive coach Martia Nelson, author of Coming Home: The Return to True Self. It's not the heavy workload per se. "Rather, the long work hours strip away the time required for family commitments, relaxation and rejuvenation, or a social life," she says. "The resulting stress and depletion from that imbalance do the real damage."

How do you know if you're on the brink of burnout? Nelson defines it as long-term feelings of being overwhelmed and exhausted, "usually both physical and emotional." If you feel irritable and frazzled on a regular basis, always feel pressed for time, have trouble relaxing, feel depressed, and are always tired, you're likely at risk.

In fact, the stress may be more significant for leaders. "It can be lonely at the top for middle market CEOs," says Nelson. "They carry greater responsibilities on their shoulders, yet often have few or no employees or colleagues with whom they can share their burdens." It can be hard to let down your guard, especially when you're facing tough times. "The need to withhold some information about the company, coupled with the additional need for the CEO to maintain a professional image and not show vulnerabilities or uncertainty, might quash conversations" with colleagues or friends who could help.

In the early stages of burnout, there may be a temptation to "work through the pain." But Nelson says this is a mistake. "Most people starting to get burnout are in denial and hold a skewed idea about the solution to their discomfort," she says. "They think that if they work more or accomplish more, they will feel better. But their attempts to do more make matters worse and accelerate the burnout." Instead, you need to take a step back and find a more sustainable way to live and work.

"Exercise is the quickest way to start recovery," says Nelson. "It reduces stress and balances body chemistry, induces better sleep, and creates a greater feeling of overall physical and psychological strength." She also advocates yoga or meditation. "Sitting for 5 to 10 minutes, quietly noticing your breath or listening to relaxing music, can increase inner well-being and resiliency that extend through the rest of the day and into the next."

If you're already feeling burned out, Nelson also encourages executives to find an expert coach. "If you're already in burnout, you probably cannot get yourself out of it alone, because you're already in a weakened state and the rip tide of burnout is so strong," she says. A savvy coach "can help you get the crush of negative thoughts and worries out of your head, and then give you a fresh perspective. You will discover options you hadn't seen by yourself because of your stress-induced tunnel vision or loss of self-confidence."

Finally, she says, you have to proactively carve out time for life balance. "Schedule at least one non-work activity that is personally rejuvenating and rewarding into each day," she says. They don't have to be long and involved, just something that can boost your spirits. "Type up a list to choose from and plan ahead." Examples could include a phone call with your best friend, dinner with your family, a walk with your dog, or a half-hour of reading at night.

For passionate and committed middle market leaders, the lure of overwork is intense — and technology doesn't help. "Constant access to phones, email, and the Internet is a seductive force on the path to burnout," says Nelson. "Without unplugging, it is impossible to have a clear dividing line between work and personal time. When that line is blurred, work almost always expands and personal time shrinks."

To ensure a sustainable professional life, it's critical to take a balanced approach over the long term.

Dorie Clark is an NCMM contributor and a marketing strategist who teaches at Duke University's Fuqua School of Business. Learn more about her new book Reinventing You: Define Your Brand, Imagine Your Future (Harvard Business Review Press). Follow her on Twitter.