Personal trainer Nardia Norman, author of Fat Attack: The Secrets Behind The World’s Biggest Loser, has seen the inside of many gyms during her career. Here are her hard truths when it comes to getting results.

You’re not working hard enough

Reality check: If you can read a magazine on the treadmill, you may as well have stayed in bed. “The number-one thing that stops people getting results is that they don’t train at intensity,” says Norman.

Instead, you should be doing high-intensity interval training (HIIT). “That’s periods of short, sharp work, followed by complete recovery,” she explains. “This means working at 95 per cent of your maximum for between 10 and 30 seconds on the treadmill, bike or rower, then resting for 30-60 seconds. You only need to do that 10-15 times and you’re done.” That’s in and out of the gym in about 20 minutes, people. You could also do running or cycling intervals outside.

HIIT creates a hormonal response that makes you burn calories for hours after you’ve stopped working out, explains Norman. It’s called excess post-exercise oxygen consumption, or “afterburn”.

You do vanity exercises

Sorry fellas — those biceps curls might load up your guns, but they’re basically a waste of time, says Norman, because you’re only working one muscle at a time. Other time-wasters include triceps pushdowns, leg extensions, leg curls and leg abductor/adductors.

Scrap them for squats, lunges, deadlifts, push-ups, chin-ups and rows — otherwise known as “compound” exercises. “You’re working multiple joints and muscles at once, which means you’ll be burning more calories and gaining more muscle (that’s toning-up for you, ladies),” she says.

They also mimic movements you make in your daily life, so you’ll be much stronger doing things like picking up the kids, a carton of beer, or carrying the groceries.

You focus on quantity over quality

Training twice a day doesn’t make you a hero. In fact, it could be sabotaging your efforts. “The more you train, the more the quality of your workouts will decrease,” says Norman. “So cut back on the overall amount, but make every session count.”

Many people don’t realise recovery is actually a very important part of losing weight and toning up. “Think of it like this: the better the quality of your training, the harder you’ll work, so the more rest you’ll need,” she says.

“If you’re doing short, sharp work, like HIIT, you can get away with training like that every day. If it’s heavy resistance training, you need to have 24-48 hours’ rest in-between sessions.”

But “rest” doesn’t equate to sitting on your bum. “Mix your sessions up, so the day after strength you can do those cardio intervals, then strength again a day or so after.”

You wing it

If you’re just working out willy-nilly with no real plan, you’re not going to get the results you want — end of story. “There’s a very big difference between exercise and training,” explains Norman. “If you have a goal of losing a certain amount of weight, for example, then you need to train for it. That means following a well-designed program.”

The best way to do it is by hiring a trainer. Otherwise, you probably won’t work hard enough, will do the wrong exercises, or spend way too much time at the gym without seeing any results. “PTs are trained to assess their clients’ bodies, needs and wants, and they can give you the tools to get you there,” she says. They’ll also keep you working hard and will change your program as you get fitter.

You don’t have a goal

So you want to lose weight — but have you ever asked yourself why? Figure out what’s really driving you, what’s going to motivate and inspire you, and what plan you’re going to put in place, stresses Norman. “The reason most people fail is because they don’t stick to a plan,” she says. “One of the biggest success points of people achieving their goals is consistency of training and eating.”

And at the end of the day, you actually have to want it. “You can fool yourself, but when you’re tired and you don’t want to get up and train, or you really want that bit of cake, your “why” has to be powerful and inspirational enough that you can avoid all the temptation,” she says.

Cassie White is a health and fitness writer. Follow her on Twitter @cassie_white or join the conversation @newscomauHQ