What are Compound and Isolation movements?
A compound movement is a multi-joint movement that works a group of muscles. An isolation movement targets a specific movement and places the majority of the training work on that muscle. Many people argue the fact that its impossible to completely isolate a given muscle, which is correct, but it is not impossible to put the majority of the training stress on one particular muscle. To understand this you must see the eccentric and concentric muscle actions and how muscles work together. Again using the example of the bicep curl (an isolation movement) as the bicep shortens (concentric) the tricep must lengthen (eccentric). Although the majority of the stress is placed on the bicep, the tricep is still being used and thus the bicep is not completely isolated.
