Looking for a challenge? David Wilson outlines a handful of professions that will test you.

If you thought lousy pay was the main reason people left their jobs, think again. With Australia's unemployment rate hovering at historic lows, "lack of challenge" is now the top reason for seeking new work, according to the Victoria-based Macro Recruitment.

Macro has found 17 per cent of job-seekers feel their jobs lack the challenge they crave.

"This spells good news for an employer wanting to hire staff," says the managing director of Macro, Daryl Keeley. Instead of offering pay incentives and training, he says, employers would get better results with "project challenge".

Successful business owners have long understood that new boredom-busting, challenging projects are key to maintaining momentum. But the survey's findings mark a shift. When Macro ran its previous national survey two years ago, during the heat of the global financial crisis, job challenge ranked third.

Conducted online between last October and January, Macro's latest survey quizzed more than 1400 job-seekers. Wages and training had dropped from being the most and third-most important reason for jumping ship to fourth and sixth, Macro found.

The survey's purpose was to shed light on how employers could better lure and keep staff. Its conclusion that inspiration carries more clout than cash might come as a surprise to many. If you have doubts, here are five challenging jobs likely to stretch your capacity for application to the limit.

Teacher

Teaching is widely recognised as one of the most stressful jobs on the market. As any student will attest, to win respect a teacher needs a variety of skills.

According to Queensland's Department of Education and Training, a great teacher should, among many qualities, be a good explainer, a good time manager, knowledgeable, cool under pressure and game for a challenge. Teaching is a passion rather than a profession, experts agree.

So, you might want to treat it as being a "lifestyle opportunity" with scepticism.

Average pay: $64,594.

Paramedic

If you want to be a paramedic, you need an extraordinary spectrum of skills, judging by Ambulance Victoria.

Paramedic duties that Ambulance Victoria lists range from restarting a patient's heart to solving social welfare issues. The job is more about helping people in their hour of need than being a hero, Ambulance Victoria says.

Squeamish? Any day, you might have to attend emergencies and accidents needing advanced life support. You might also assess, treat and manage patients on the way to hospital.

Other duties include stretcher-bearing, high-speed driving and "trauma setting" resuscitation. It is hard to think of a job that poses more challenge.

Average pay: Pay ranges from unpaid volunteer positions to more than $100,000 a year.

Intelligence officer

The Australian Secret Intelligence Service (ASIS) describes the work as "unique, challenging and exciting".

The job of an intelligence officer is to spy - or rather "gather intelligence overseas" - to help protect and promote Australia's interests and security. Among other things, an ASIS applicant needs a three-year degree, a driver's licence, "personal presence and impact", "excellent written communication skills" and "personal courage".

Clearly, the job can take you miles out of your comfort zone but everyday intelligence work is far from the James Bond style.

Average pay: $66,941-$89,780 (plus superannuation).

Firefighter

There is much more to fighting fires than being a "smoke-eater" - Fire and Rescue NSW describes the work as "varied, challenging and rewarding".

As a firefighter, you must tackle hazardous, toxic and flammable materials, conduct recoveries after natural disasters and attend motor vehicle accidents.

Oh, and you also must be ready to comfort victims and give basic first aid.

"Firefighting is physical and psychologically demanding, especially during major emergencies, and involves quick thinking, teamwork and endurance," Fire and Rescue NSW says. The job demands a high level of fitness because of the need to combat fatigue and toil away amid heat, smoke and dust.

Average pay: $52,000.

Australian Defence Force

The Australian Defence Force's slogan reads: "Army. Challenge yourself." The ADF is the bruising embodiment of a tough job.

Its syllabus covers everything from drill, first aid and military law to weapons training. Then there is the boot camp physical fitness dimension that tests your will to pump out push-ups and perform lung-busting "beep test" sprints.

And do not forget the possibility of "active service" (war).

Talk to any army veteran and you will hear that almost every recruit gets called up eventually. Hold that thought if you think joining up sounds glamorous.

Average pay: Varies wildly, depending on rank, role and experience. Basic training wage is $32,800.