The best time to do a cardio workout is on an empty stomach in the morning because the body will tap into its fat stores for energy, instead of burning carbohydrates and then reaching into the fat.
Fat burning zone
To burn the most fat, try to hit about 65% of your maximum heart rate. This is called the fat burning zone.
Progress gradually
Begin with small time periods with cardio exercises Increase speed and time every week. This will help your body to not feed on muscle, especially if you‘re dieting at the same time.
:: Aerobics tips ::
Stretch
Remember to stretch before class, even if you arrive late. Do calf stretches, to warm up your muscles first.
Exercise right
Your warm up and cool down sessions should not be included in your time allotted for the actual aerobic exercise. Remember to keep your heart rate between 70-85 % for a 20-30min per session.