We've run with a lot of people over the years who put down 15 miles and then eat an egg sandwich, skip the stretching, and go about their day. That's fine, they've earned it. But it's a lot like lifting weights and then skipping the recovery shake: We're not achieving the full benefits of the exercise if we don't recover properly.
The Supported Fish is an ideal pose for recovery. It's also very easy. Just lay down on your back, reclining over a rolled blanket. Stay there for 20 breaths or more. This stretches out the chest and encourages deep breaths.
Benefits: Helps with recovery and relieves tension.