Sprint your cardio
All you need to need to do is inject a high intensity burst in your regular exercises (jogging, swim, walk, cycling) for a short interval of time. This intensity will elevate your metabolism which will lead to more calories being burnt in the process. If you are a regular walker, do sprint running for 30 seconds every 5 minutes. If you are a swimmer, try a fast lap in between 3 slow laps of any stroke. As you get familiarized, you may increase the interval. You can use a fitness tracker to keep track.