Each year millions of people set self-improvement and fitness goals for the year ahead, but too often they don't pan out.

University of Sydney psychologist Dr Michael Cavanagh said even when people had the best intentions, most New Year's resolutions were doomed.

"I think the figures are that around 79 per cent of New Year's resolutions fail," he said.

"Often times they are set in a way that is too constraining for them to be effective."

Dr Cavanagh said inflexible goals required individuals to rely too heavily on their will power, impairing further decision-making and self-control.

Fitness First Canberra City manager Matt Muller said the first months of the year were the busiest for new sign-ups and current members.

Mr Muller said it was important to engage people's motivations and New Year's resolutions at the start of the year, but ensuring members kept it up took work.

"We put a really heavy focus on keeping contact with new members in the first 12 weeks. The reason is that they are much more likely to stick out their training once they have formed their exercise habit."

Dr Cavanagh said incorporating your goal as part of a routine and telling others reduced a reliance on will power alone.

"It's true for many people that it's easier to fail yourself than to fail others," he said.

Owner of Define Fitness, Nathan Hitchcock, said it was interesting that across boot camp classes and personal training sessions women stayed committed for longer.

"Men drop off quickly because they think they can do it themselves."

Mr Hitchcock said his clients came to train their bodies, but that unlocking sustained motivation involved a shift in thinking.

"Their brain can be a limiter - their body can do it, but they have to let themselves," he said. "We tell little white lies, like miscounting reps or distance to prove to clients that they can exceed their own expectations."

Mr Hitchcock said the fitness industry did get a boost at this time of year, but that results came only after the hard yards.

"It shouldn't matter whether it's the start of the year or the end - if you're starting a program, you need to stick to it," he said.

1 - Create a vision board.

Whether it's tangible or digital, choose images that remind you of why you are making a positive change and increase your motivation.

2 - Record how you feel.

Start by asking yourself the important question: why are you doing this? Take notes on how you feel, especially after eating and exercising.

3 - Talk to yourself.

Tell yourself you can! Everybody has the willpower to become healthier. If you slip up, know that everyone else does too. Don't stress, and get back on track.

4 - Inquire about body science.

Often, sharing the information you have discovered with others is a positive motivator.

5 - Remember why you have goals.

Think about why you started and how far you have come since then. Your goals will evolve, this is bound to happen. You will get there and when you do, celebrate it.