Can't avoid philosophy

I thought I was going to write about my workout today, and avoid philosophy, but I don't think I'll be able to do that.  It was a really fun workout, completed after my final physical therapy session, with a mix and match of core and upper body exercises with a few burpees thrown in.  I am slowly buying into the idea of short intense training, and today was a breakthrough as I abandoned the rule that any run shorter than 4 miles is a waste of time.  I ran for about 14 minutes today (warmup + "tabata" + cooldown).  Tabata is a protocol involving 8 repeats of 20 seconds maximal efforts and 10 seconds rest, introduced to me by my sister-in-law last summer.  It works, at least according to what I've read, and it definitely makes it feel like a workout.  The thing that blows my mind is that it twists specificity of training around on its head.  If I am training to run a fast marathon, shouldn't I be running fast and long distances?  This is in fact what I did 5 years ago or so.  But maybe I'm actually training for dynamic power output and high cardiovascular workload, and a fast marathon will be a side effect.  In any case, it's fun to branch out, and we'll see if it pays off in terms of performance.  It's all a question of goals, and fun is not a bad one.

2 days ago: PT/back exercises, 10 burpees
Yesterday: run 4 m, 11 burpees
Today: PT/back exercises; core (100 twist/leg up situps, 1 minute up-down pushup hold in 10 second intervals; boat pose 3x20 sec; 15 hanging knees-to-elbows, 10 side arm pushups); 20 pullups (10 standard, 10 chinups); tabata treadmill run (~7 min pace at 5% grade) with 5 min warmup and 5 minute cooldown; 12 burpees