Complexes were originally used as a way for Olympic lifters to build technical strength, but it's also a great method for building muscle and burning fat at the same time.
A complex is where you perform a series of exercises without putting the bar, kettlebell, or dumbbells down. When you do a high number of rounds, complexes challenge your muscular endurance. And the stronger you are the harder they become.
Unfortunately, the vast majority of complexes aren't as good as they could be. Why? Most mix upper and lower body exercises. When done as a superset this is fine. But since you don't put the bar down in a complex, you'll always be limited by what your upper body can do – it'll either be too easy for your lower body or too hard for your upper body.
Split up your complexes into upper and lower. You'll get a great challenge for each, without putting yourself at risk of injury. Try the lower-body "death complex" below:
That's four rounds of:
By taking out the upper body exercise, you get a much better stimulus for your legs, while also leaving you gasping for air.
For upper body, try this:
That's 3-5 rounds of:
Complexes can be an amazing way to build technique and strength, shed body fat, and save time. By splitting up upper and lower complexes, you'll get a better workout and decrease your chance of getting injured.