There is NO WAY I won't improve training like this

I heard it from a few swimmers... "Today was the hardest day".  I could swear I was in basic training for the military.  My muscles was abused in ways I didn't know where possible.  We began the morning with a 1.5 mile run on the track which was interrupted every 200 meters by 10 pushups and boxing your training partner with boxing gloves on.  Each time we stopped, we would box in a different way, from twisting at our hips with left, right, left, right hooks, to sitting on our rear end and boxing upward to our partners hands.  It was a short set that certainly woke up my muscles.

We moved inside and began a 16 station training circuit.  Every machine and exercise was done.  Beginning ab twists against surgical tubing, to throwing medicine balls down 8 feet (we were standing on metal boxes), to squats and the swim bench, finishing up with as many pullups as you can do in 30 seconds.  I'm happy to report I was on par with everybody else however my last :30 second pullup attempt only yeilded 5 full pullups, wow.  It was the most rigorous training circuit I've ever done, I was dripping with sweat at the end.  Afterward we got changed for the pool and began what the coach said would be a "quick swim".  I don't want to get caught up in what "quick" SHOULD mean, but the 3,000 meter workout that followed redefined the word for me.  Again it was mostly aerobic on short intervals.  By doing backstroke, you could find me at the back of the group.  I hope my teammates realize I'm swimming a statistically slower stroke than they are, otherwise I probably look borderline pathetic.  I seem to hold my own in all the workouts.  As we ended the morning workout, a teammate looked at me, shook his head and said "see you in 3 hours".  It took the smile right off my face.  It really put the next 1 year of my life in perspective.  The workouts are scheduled 3.5 hours apart.  Really not much time to do ANYTHING, including sleep or eat.

The evening workout was a 2 hour swim practice.  We did aerobic swimming with lots of work on turns and starts, followed by a 40 minute set for just the post grads in the deep end which was a 4x circuit of:

25y no breather swim
50y double pulldown BR
4 x pushouts
25y underwater swim (yes, a full swim stroke)
50y kick on front, no board
3 x :25 on :15 off abs on pullup bars, lifting legs
25y blast FL
25y easy swim
200y hip driven free
3 x :40 on :20 off ab work (situps, etc) 

It was a manageable set because it was not on any interval, I found myself lagging behind the other 4 sprinters in the water but it didn't matter, I was doing everything as written, just not killing myself on the timing of it all.

Afterward, hot tub, food and sleep, followed by a night of work. There is zero chance I cannot improve my 100 Backtroke training like this.