The interval training portion of your workouts is very important for fat loss. Not only has research shown that long, slow cardio does not work that well for fat burning, but studies also show that short burst exercise works better to help you lose belly fat.
Unfortunately, just saying the words "interval training" can scare people, plus some trainers make it far too complicated for people who have never done interval training in the past.
The great news is that sprints can be made by everyone, even beginners, provided you have them exercise at the right level of intensity for their fitness level.
Generally, I recommend people use the stationary bike for their interval training workout simply because it is easy to transition between hard an easy and you do not have to worry about falling off the treadmill or advanced sprinting. Also, you'll need an extra warm-up with sprinting intervals.
In this example I am going to use the treadmill and I recommend doing your short burst exercise immediately following your strength training. However, if you are not fit enough, then you can do sprints or cardio training on your off days instead. Just be sure to have 1 full day of rest. For your interviews, you will want to train 3 days / week.
Below I am going to detail 3 interval training workouts from the beginner preparation phase.
Start with a 5 minute warm up, exercising at a slightly harder than what you'd do for a regular cardio pace. For example, if you normally do 3.5 mph, then do 3.7 mph for 3 minutes.
This would be at a subjective 7/10 intensity level. So if your regular cardio was at a 6/10, then think about that intensity and then go a little bit higher. This will allow you to exercise harder than you normally would if you went for 30 minutes straight.
After 3 minutes at a 7/10 intensity it is important to bring it down to a nice, easy 3/10 intensity for your recovery. At this pace you will remain for 2 minutes and it will allow you to work extra hard when you bring it back up to the 7/10 intensity.
Do this for a total of 3 total intervals of hard and easy, counting as one. Finish with a 5 minute cool down. This interval training workout will last a little over 20 minutes.
This interval training workout is a little more difficult than workout A. Complete your warm up and then do 90 seconds at an 8/10 intensity. This would almost tire you out after 90 seconds at this pace, and then follow with a 2 minute recovery at a 3/10 intensity. Complete for a total of 5-6 intervals, followed by a 5 minute cool down, lasting a total of 20-25 minutes.
This is a high intensity cardio workout. To complete workout C, you will perform 20 minutes of straight cardio at a 6-6.5 / 10 intensity. So this would be something that tires you out after 20 minutes and something you could not do for 25 minutes. Again, begin with a 5 minute warm up, 20 minutes of cardio, and follow that with 5 minutes of cool down.
Do each of those workouts once per week at the end of your resistance training workouts and you'll burn fat fast.