And most busy people's morning breakfasts are not significantly portioned enough to risk indigestion against a workout that is probably about 5 minutes at the m

And most busy people's morning breakfasts are not significantly portioned enough to risk indigestion against a workout that is probably about 5 minutes at the max (1.5 min. for rest time plus .5 min. for timing wrong plus 3 min. for doing LOTS of push-ups, theoretically). That changes if you throw in the core routine. Most of us are just eating a bowl of cold cereal or having some toast. Not a full English breakfast.