The weight you train with and the number of reps you complete can have a big impact on your calorie burn. To burn more calories during the workout, higher reps do the trick. Researchers found that when participants used a weight them to complete 10 reps on the bench press, they burned about 10 percent more calories than when they used a weight that limited them to 5 reps.
THE MORE REPS YOU DO, THE MORE CALORIES YOU BURN!!
However,while using heavier weight for fewer reps burns fewer calories, it burns more calories when the workout is over and you go about the rest of the day.
When you lift with weigh that limit you to 6 reps per set, the boost in your metabolic rate for 2 days after the workout more than doubles the boost you get when you complete 12 reps per set.
WITH THIS BEING SAID, THE BEST THING TO DO HERE IS TO USE A COMBINATION OF BOTH HEAVY/LIGHT WEIGHTS IN YOUR WORKOUTS.