The US Naval Institute Blog has a post by a Seaman LaVigne USCG suggesting steps to improve the fitness of Aviation Survival Technician candidates.
Perhaps some of the information he suggests for this very limited population might also help other coasties achieve an maintain better fitness.
When I first published this there was an error in the link due to the way the USNI structured their blog that I did not recognized. It was corrected almost immediately but those who follow this blog will have gotten the version of the post with the incorrect link.