Absolutely, this is true. I'd say your 28 hour estimate is high by a factor of 3x at least. But without exercise, the risk of developing health problems that

Absolutely, this is true. I'd say your 28 hour estimate is high by a factor of 3x at least. But without exercise, the risk of developing health problems that destroy all that kid-free time is higher. Getting a back injury from lack of core strength or losing your energy due to obesity harms your entire life. I'm suggesting regular exercise as a cautionary piece of advice.