I think single digits is nonsense to start a blast.
theres not really any benefit going much bellow 12-13% unless youre struggling with severe insulin sensitivity issues.
a self assessed 17% (which is likely higher because humans are really bad at estimating bodyfat) is for sure less than ideal to start a mass gaining phase. but simply dropping down to 12-13% is plenty for most people to get their digestion sorted, insulin sensitivity set, and primed for a good response to the caloric surplus and training.
I personally maintain somewhere in the ballpark (my estimate, could be wrong) of 12-14% for both growth and health/maintenance phases and only enter into a true deficit if im dealing with digestive issues or to get my fasted BG more under control, or to reset food sensitivity after eating in a surplus for a year plus.
im currently at 250lbs and attached photos are form this mornings check ins deep into a full blown offseason growth phase.
Just like there is no reason to get sloppy fat during your growth phases, there really isnt much reason to get super shredded before a blast/push so long as your health, digestion, and food response are all good
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