How tired do you feel at the end of an average workday? Do you have enough energy to hit the gym or spend time with your family? Or does working eight (or more) hours at the office make you so worn out that you're about to collapse from exhaustion?
Workers in every industry struggle with fatigue and burnout , but if you repeatedly find yourself barely able to get out of bed in the morning, the problem may not just be your sleep schedule or stress-management techniques – it could be that you're stuck in an overly demanding job.
Many employees get worn out at work , but how can job seekers tell which careers are more arduous than the rest? Is it more exhausting to work at a job that requires extreme physical activity, or one with a high stress level ? Police officers  frequently put their lives on the line and engage in dangerous high-speed pursuits, but do they experience more fatigue than senior corporate executives , who shoulder responsibility for the financial security of hundreds (or thousands) of employees? And how do positions with extremely long hours, such as truck driver , rate for their overall "fatigue factor?"
While each is tiring for very different reasons, all three of these positions are among the most-demanding jobs you can find in today's employment market, according to a new study from CareerCast.com's 2009 Jobs Rated Report . Compiled using information from the Department of Labor and Jobs Rated's exclusive data on 200 different jobs , the new report ranks positions based on a combination of work hours, stress and physical demands  to determine the eight most-demanding jobs overall, along with separate rankings of the most exhausting blue- and white-collar positions.
So which career has the greatest number of exhausted employees at the end of each workday? In this year's Report, firefighter  ranks as the most-demanding job by a significant margin, thanks to a combination of long hours, life-threatening situations, physical demands, and responsibility for the lives of others while on the job. However, while police officer has a similar set of requirements, it slides to fourth place, behind surgeon  and corporate executive. Why? Because while police officer ranks extremely high for physical demands, it places below surgeon and senior corporate executive in both stress and average work hours.
If you're looking for a new job  but are worried about conserving your energy, you might want to think twice before starting one of these careers, the nation's eight most-demanding jobs:
The list of most-demanding jobs overall includes a mix of both blue- and white-collar positions, but some of these – sailor  and psychiatrist , for example – rank high for very different reasons. Apart from examples such as firefighter, a majority of blue-collar positions wear out workers because of their physical demands, while demanding white-collar jobs earn their rank due to long hours and anxiety.
To measure the fatigue factor of jobs against more comparable positions, CareerCast.com researchers analyze the most-demanding white-collar and blue-collar jobs as well, broken into separate rankings.
Continue to the next page to see the 8 most demanding blue-collar and white-collar jobs
In compiling lists of the most demanding white- and blue-collar jobs, CareerCast.com researchers examine data on each position's stress level, work hours and physical demands. Looking at exhausting white-collar occupations, the most-demanding job is surgeon , which also ranks second on the overall list. A surgeon's high fatigue factor is due to extreme stress and long hours that can include being on-call late at night. While not as physically demanding as firefighter , surgeon ranks highest among white-collar positions for physical activity as well. Other white-collar jobs with high stress include senior corporate executive , attorney  and physician , while clergy  and pharmacist  make the list largely due to long work weeks.
For job seekers looking to avoid stress, these are the nation's 8 most-demanding white-collar jobs:
While a majority of white-collar jobs are demanding due to stress and long hours, employees in blue-collar positions tend to engage in more intense physical activity. That said, firefighter is the most-demanding blue-collar job, and along with police officer, includes the stress of being responsible for the lives of others. Roustabouts , who maintain oil rigs, also experience anxiety due to the risk of personal injury, and sailors must be concerned about falling victim to piracy. Truck drivers  are required to spend long hours behind the wheel, while automobile body repairers  and tool-and-die makers  shoulder heavy physical demands.
For workers who don't mind late nights and heavy lifting, here are the nation's 8 most-demanding blue-collar jobs:
Depending on your personality, working in a highly demanding job can lead to physical exhaustion, anxiety or intense burnout that can be difficult to cure without changing the way you cope with stress . While in today's market many employees may be glad just to have steady employment , if your workdays are overly draining and you find it difficult to recover, it may be time to look for a new career .
On the other hand, if you’re the type who cares little for sleep, loves pressure and believes hard, physical work only makes you stronger, one of these highly demanding positions could just be the perfect job for you .