I don't recommend pumping up the intensity for your entire workout as that will be impossible to maintain, and because it's proven that interval training is the best way to get the most caloric burn. Not only will you burn calories during your workout, but you'll also continue burning calories for hours after you're done. That's because this type of intense exercise really pushes your body so much that after you sweat it out, it has to go through a recovery period. This takes energy, meaning it burns calories, so you end up getting more bang for your buck as compared to a workout at a consistent and low intensity.
I know it can be frustrating to hit the gym regularly and not get any closer to your weight loss goals, so give this tip a try. Kick it up a notch by adding intervals to your cardio workouts such as sprints, mountain climbers, jumping rope, or plank V jumps.