Did my recent workout changes possibly cause me to lose more muscle vs. fat?

So the for last two weeks I just went from a full body 3x a week routine to a 4 day split workout. In the last few days, I've noticed that my pecs look a lot smaller than they used to. I am afraid that my only working my chest once a week, my calorie deficit is causing me to lose too much muscle during my cut. Or, do I just not have that 'pump' from working my chest every other day like I used to.

 

Also, on Tuesday, I spent 5 hrs. moving logs with little to eat, so I burned major calories. Could my lack of food while doing that have caused my body to start eating a visible amount of muscle?

 It's just the effect of not being pumped up all the time - muscle loss can be a bit faster than muscle gain, but it's not that fast.  Unless you break the maximum deficit of 31cal/lbs fat mass/day limit, you won't lose significant muscle - you may have had some extra muscle fibre breakdown from your work but as long as you ate adequately after the job was finished the increased protein resynthesis in your muscles should replace any losses.

 You may not be as pumped up from your workouts, but assuming you're at a level where a split schedule makes sense you're going to see more muscle growth from the more intense workouts you can sustain with the lowered frequency.

this is an interesting point.  when i looked around for ideas about "pump," which i suspect is the major culprit for your muscle appearing smaller, i mostly got results relating to reps.  still, i think this excerpt from one article is useful:

Fourth, by increasing time under tension, a moderate-repetition set maximizes muscle damage—a fact that has been shown to be imperative to increases in muscular hypertrophy (2). Theoretically, the longer that cross-bridge formation is maintained during training, the greater the potential for damage to the tissue. Because the duration of cross-bridge formation is shorter in a low-repetition set than in a moderate-repetition set, there is less time for myofilamental damage to take place.

is it possible that when you were doing the combination lifts, you were doing them slower, w/more time under tension?  and now, w/the "simpler" lifts, you're doing them faster?  i feel like i'd barbell curl a lot faster than i do a front squat to push press.  you know? so that might be a factor.

Original Post by melkor:



 You may not be as pumped up from your workouts, but assuming you're at a level where a split schedule makes sense you're going to see more muscle growth from the more intense workouts you can sustain with the lowered frequency.

Well then that raises the question of wether or not a split workout is appropriate. I just changed after doing full body workouts for the last 1.5 years.

 Sounds like a good time to switch, really - you might want to keep in mind something I learned from Chris Shugart once upon a time; that you get the best training response from radically changing your training philosophy on a regular basis. I've just finished with a 3xweekly whole-body workout, now I'm on an upper/lower split, later this year I'm going to do a 5-day split, before changing back to a 3xweekly whole-body workout.