I love the sound of that swimming too. It is so good to have an exercise that also supports your body & doesn't cause pain. Also great to have some personalised coaching. I used to love water aerobics.
I got started down this track wondering why my meticulously weighed and counted calorie deficits were resulting in greater than expected weight loss. 3500 calories is a pound, right? Turns out that isn't the whole truth. 3500 calories is 1 pound of fat, but you don't just lose fat - you also lose lean mass along the way. And 1 pound of muscle is only 700 calories (you also lose other bits in "lean mass" but we'll ignore those).
Each person will lose a different ratio of fat to lean mass, but in general the research seems to suggest 70-90% of your lost weight will come from body fat. That suggests you need a calorie deficit of just 2660 to 3220 to lose 1 pound of body mass. Not only is that a far cry from 3500, that's still quite an extreme range!
How exciting! It's kind of incredible just how much has changed in a relatively short amount of time.'m also 1 month out from my first triathlon, a half Iron, and I'm feeling pretty confident that I can finish strong (albeit with a slow time) as long as I remain healthy.