Developing Strength is easy when you first start hitting the gym.

“Your muscles go through a learning process, so almost anything you do triggers growth,” says trainer Mike Boyle. “But eventually your muscles adapt, improvements level off and you have to train smarter to see results.” Hit the refresh button by purging your fitness plan of these common pitfalls.

Mistake #1 – You don’t train your legs

Most guys’ workouts are top-heavy. “They focus too much on the mirror muscles – the chest and arms,” says Boyle. A sign of true fitness is a muscular backside. “Your largest muscles, including the are in your lower body. Training them releases hormones that build size and strength everywhere else.”

Try this:

The elevated back-foot split squat. Hold a bar across your upper back using an overhand grip. Assume a staggered stance, with your left foot in front of you and your right foot behind on a 15cm step or box. Lower your body as far as you can and then push back up to the starting position. Do 10 reps, switch legs and repeat. That’s one set; do three.

Mistake #2 – You run too much

Logging distance isn’t a total waste of time, but it’s close, says Boyle. This is because your body adapts quickly to repetitive movement – and that’s running in a nutshell. What’s more, running doesn’t activate your fast-twitch muscle fibres, which are great fat burners and body builders.

Try this:

Train in intervals – short bursts of intense activity followed by active rest. Set a treadmill to an eight percent incline and run for 30 seconds. Then rest for one minute. Do this 10 times. This type of training leads to gains in aerobic and anaerobic performance that are significantly greater than with steady-state cardio, according to a recent study in the Journal of Strength and Conditioning Research.

Mistake #3 – You lift too slowly

Explosive lifting leads to faster gains. The reason? “It activates more fast-twitch muscle fibres, which have the greatest growth potential,” Boyle says. “So lift like you mean it.” You’ll also crank up your heart rate, increasing your kilojoule expenditure.

Try this:

Do the lifting phase of each exercise as fast as possible. The actual speed of the lift doesn’t matter. “As long as the movement is explosive,” says Boyle, “your body will recruit fast-twitch fibres.” Then take at least two seconds to lower the weight.

Mistake #4 – You stay in your comfort zone

Professional athletes don’t sharpen their game by only working on their strengths – they also eliminate weaknesses. You should do the same. “Doing only the moves you’re familiar with is a cop-out,” Boyle says.

Try this:

Do compound exercises (that is, moves that target multiple muscles) like deadlifts, chin-ups and dips. “They’re some of the toughest ones you can do and you can’t make serious gains without them,” says Boyle. Boost your results with the instant exercise upgrade on this page.