Motivating yourself to get to the gym for a workout is hard enough, so don't waste your time by slacking off when you get there.

If you're keen to see better results, a few simple changes could be all you need to boost your metabolism and burn even more calories.

These six things are proven to maximise calorie burn and make your body work even harder than usual, so give them a try next time you're exercising.

1. Work out in the morning
Your energy levels are generally at their highest in the morning as you've just woken up from a night's sleep, so it's natural that you'll be able to work harder at this time of the day. If you're not a morning person though, choose a time when you usually feel most energised, be it after work or on your lunch break.

2. Warm up well
Stretching or jogging for 5 – 10 minutes before an exercise session not only loosens the muscle but also gets the blood flowing so that you're burning calories before your workout has even begun. Ease your body into your workout to see better results.

3. Mix it up
A slow and steady workout might seem like the best way to do things, but it's important to give your body variety. Try a series of high-intensity exercises like jumping jacks, wall sits, lunges or push-ups, doing 30 seconds of each and taking a 10 second break between each one. If you're doing strength training, make each set a "superset" by combining two exercises in quick succession before a short break.

4. Don't be scared to use heavier weights
Many women have a tendency to go for small 2kg or 3kg weights for fear of getting "bulky," but using heavier weights is the best way to burn calories, and we promise you won't look anything more than toned and lean. Research has shown that using heavier weights for fewer reps burns 25% more calories than using smaller weights for more reps (eg. 5kg 10 times versus 10kg 5 times).

5. Eat shortly after your workout
Refuelling your muscles after a workout is essential for helping them to repair themselves and get stronger. The stronger your muscles are, the more calories you'll burn every day. Simple. So be sure to eat a protein-rich snack within 2 hours of finishing your exercise session.