More confusion

I'm trying out a foray into "extreme fitness", which for me, so far, boils down to mixing it up a bit. A good example was Monday's push-up/run day. After a bit of googling, I came across another workout that I tried today. It's called a 3-2-1 workout, and I freely admit to hijacking this from mensfitness.com, however this is modified for my own usage. Goes like this:

• 10 minutes cardio warm-up (no-brainer here... that's a mile run)
  
• 3 sets, 20 reps each, of 3 exercises. I chose incline dumbbell press, shoulder press, and incline two-arm rows. 30 second rest between sets.
  
• Interval cardio. I did a one-mile run with 2 minute warm-up, then 4 one-minute tempo intervals @5k or faster pace, then cooldown until I reach one mile.
  
• 3 sets, 20 reps each, of 2 exercises. I did preacher curls and triceps pull-downs. 30 second rest between sets.
  
• Repeat Interval cardio.
  
• Core. 2 sets of 20 reps each: hanging leg lifts, laying leg push up things, and incline sit-ups. I didn't make it to the last set of incline sit ups, I had nothing left in the tank.
  

When I began the first interval session, I couldn't get my left arm to lift to my normal running bend. It hung a little lower than normal. This was a great workout, and I aim to do something similar 2-3 times a week, or more. We'll see how this goes.