1) 5-10 mins warm up
2) Max 30 mins resistance
3) Max 10 mins cardio
4) 5-10 minute cool down
IN THAT ORDER.
Keep it efficient. Efficient is effective. No more time wasted.
This shit works.
Going light over a prolonged period of time burns calories BUT it is certainly not the way to go if you're aiming for fat loss. Chances are that you'll just eat those "extra calories you earned".
Stable cardio will elevate your cortisol levels. Cortisol is a hormone which will encourage your body to store fat around your middle section. Not ideal.
High intensity interval training (such as Tabata), on the other hand, helps your body to keep burning body fat even for days after the actual workout. And it's great because you can do it despite your fitness level -- if you're not very fit then you'll just need to do things a bit slower to begin with. As long as you feel like you're genuinely trying hard, that's all that matters.
Because if it's hard, it will work and get you the results you want.
P.s. If you've got medical concerns, please have a catch up with your doctor first to make sure you're fit enough to embark on such a strenuous training protocol.
Frog squats are brilliant for getting your heart rate up and your legs working. Make sure you're bending your legs considerably every time you're doing the move instead of just bending over to reach for the floor. Your back should stay flat throughout the exercise.
Find a video of me doing frog squats here.