We're all just carbon, water, starlight, oxygen and dreams
I'll just continue to sit here reading you guys, jealous that you've got enough time to consider one long or two not-as-long workouts a day.
I'm living vicariously through you for sure, Chris.
SO it's an old thread, but I'll jump in as I just had this conversation with my coach this week.
2 a days are helpful in two situations. Maybe more.
First one: you are new, recovering, or working on a specific stroke problem. It is better to do shorter sessions where you can focus and do good work than a long session where you get really tired at the end, and your technique etc fall apart.
Second situation: you are very fit and have the time to put in two excellent sessions.
I'm right now trying to correct an issue with my catch, and I am coming back from back injury, so I'm in the first one. Two a days can be a super effective tool to build base and endurance, but that said, once a week I still do one long swim....