Although I can attribute my weight loss to my diet more so than I can to Judo, it is my regular Judo practice that has increased my stamina and overall well-being.
When I first started Judo, I had very little steam in Ne-Waza and lagged significantly behind in calesthenics. Say I was able to perform maybe 30% of the Calesthenics load in our warm-up and warm-down excercises. Now I am at 90% capacity (my goal is 110%, so that I don't feel winded by the workouts).
One of the places where I have seen significant improvement is in the spinning excercise. The spin excercise is a warm-down/stretching excercise, in which you start in a seated position, spin your legs around and behind your back until you are prone, and then continue around again until your are sitting up. In august, I bowed out of doing them, because I just couldn't. Then I started by completing just a handful of 30-50 spins, and poorly. Now I can do about 20-25 full spins with no problems (it's the last 5-10 that kill me) and at the tail end of each I will be sitting up about 315 degrees from where I started - only 45 degrees to go.
I also finally got to meet Mark one of my virtual friends from the Judo Forum. He returned to our Dojo after a 9-month absence, and he was my Uke for Uchikomi. Sensei urged him to do his Hane Goshi, which he remembered being really good. It was probably some of the very best technique I've ever seen for that throw. I of course, immediately tried it afterward and he and Sensei watched, and then critiqued.
I entered the throw with a two-step move, that is, from a right-handed grip, I stepped my left foot towards Uke and then planted my right foot before pivoting on the left to execute the throw.
They showed me a much more efficient way of doing this - skip the second step by turning and planting with the left foot and then pivoting into the throw. It was phenomenal. I now see Uchimata and Hane Goshi in a whole new light. I still, however, need a lot of practice, but now that the stage has been set, I will hopefully be able to put a new set of throws into my arsenal.