Yes. Isolations provide a more direct method of building the mass of specific muscles (hence the term 'isolation').
Hypothetically, a workout can be constructed which is comprised solely of isolation exercises, but it would not be a very good one.
Overall muscle strength AND size is built most successfully by using compounds and stressing the Central Nervous System in ways that isolations just can't do.
A workout which incorporates both heavy compounds first and isolations second is a tested and proven training regimen.
Last edited by Abaddon; 07-11-2011 at 08:32 AM.