List boss Jason McCartney said the club was rapt the pair was continuing.
“We didn’t hesitate to offer both Heath and Shane new contracts given what they were able to achieve this season,” McCartney said.
“We firmly believe they have more quality football in them and are looking forward to the pair of them helping us get to where we want to go as a footy club.”
The Giants will re-rookie Jake Stein, Tom Sheridan and Zach Sproule after delisting them while they delisted former Blue Dylan Buckley who became a popular member of the group during his time at the club.
The Giants traded out Jonathan Patton to Hawthorn and Aiden Bonar to North Melbourne while Adam Tomlinson joined Melbourne as a free agent with the club still determining how many list spots they have available heading into the draft and delisted free agency period. They also lost Brett Deledio and Dawson Simpson to retirement.