The real tension
Pipeline reviews, board decks, and closing pressure don't stop because it's a school night. Two pre-teens don't wait for a quieter quarter either. The problem was never one competing with the other, it was treating one as scheduled and the other as whatever's left over.
The calendar is the operating system
Anything that isn't on the calendar loses to whatever is. That applies to a workout the same way it applies to a forecast call, so training time and specific family time both go on the calendar as fixed blocks, not as intentions. A recurring block reading "gym" or "pick up the kids" gets defended the same way a call with your CRO would be.
In practice, that usually means protecting a small number of non-negotiables rather than trying to schedule every hour: one daily health block, a fixed evening cutoff a few nights a week, and specific recurring time with your kids that doesn't move for a meeting that could've been an email.
Boundaries that actually hold
A boundary that only exists when things are calm isn't a boundary, it's a preference. The ones that hold tend to share three things: they're specific (not "more family time," but "home for dinner Tuesday through Thursday"), they're visible to the people who'd otherwise book over them, and they get defended the same way under pressure as they do on an easy week.
Travel is where this breaks down fastest, so build in buffer deliberately: a recovery block the day after a trip, a standing check-in with your kids by phone or video if you're away, and a default of protecting the first health block back rather than letting the backlog eat it.
What gets protected first
When something has to give, and something eventually will, the order matters: the health block first, since everything else depends on having the energy for it, then the specific protected family time, then deep work, then everything else. Meetings expand to fill whatever's left, they don't need protecting, they'll take the time regardless.
Identity, not willpower
This only holds up if it's not a daily negotiation. The same principle that applies to training applies here: being present isn't something you talk yourself into after a hard day, it's just the default you've built the calendar around.