it really depends on what you want to achieve and how quickly. I run a number of Indoor and Outdoor BootCamps combining HIIT (High Intensity Interval Training) along with Boxercise (Upper body and core) and running all these combined are great for burning fat and building muscle along with increasing your endurance, do not worry about building muscle you will not turn into a body builder.
The classes I run are for an hour and we meet 3 times a week, each class will concentrate mainly (not completely) on specific ares upper body, core and lower body movements.
I find compound exercises (Exercises that involve 2 or more joints and large muscle groups working together) are great such as Body weight Squats, Burpees, lie down stand ups are great !! these will burn fat and build muscle.
Ensure you rest between attending sessions this will reduce fatigue and increase your performance and ability to adapt to alternate exercises.
Eat a calorie controlled diet. 1LB of fat = 3500 Calories, do not consume more than you can burn. Typically you can burn up to 1,000 calories in Bootcamp and Boxercise training session
When your training session finishes ensure you eat, skipping your meal will increase fatigue and destroy the hard work you have completed
Members of my BootCamp have been with me for over 12 months and have seen major fitness and overall body shape improvements
My training is run from Altrincham in Cheshire. For more info see http://www.bespokelife.co.uk
Keep up with the Zumba and I am sure you will see there results
If you decide to include BootCamp and or Boxercise in your training plan ask your instructor for proof of qualifications!!!...