Once triglycerides are stored, are they released as triglycerides in the bloodstream again or broken down further?

Broken down. Stored triglycerides are your long term energy storage sites. When energy is needed, the specific enzymes needed to break down the triglyceride stores are activated so that the energy stored in th chemical bonds can be mobilized and used by the issues and cells as needed. To that end, the triglycerides are broken down to free fatty acids and may be recombined into other molecules as needed.