Well you are doing a lot of conditioning work and you are likely on a restricted caloric intake, which more than likely supplies a low amount of carbs.
The problem is that glycogen depletion is linked with an increase in AMPK. And in turn when this enzyme goes up, it can turn off mTor. MTor is the trigger that activates protein synthesis. Protein synthesis is necessary for muscle repair and growth (and even maintenance).
Simply put if you are already burning a lot of fuel, especially glycogen it will not take a lot of lifting volume to kill your progress and more than likely end up actually end up losing muscle mass.
I understand that losing fat is an emotional thing. We want the fat off NOW. But if we do too much the risk of losing muscle mass is very real.
I do like a pull/push/legs rotationā¦ and for 4 weekly workouts you could either rotate through the workouts. e.g.
DAY 1 Pull
DAY 2 Push
DAY 3 OFF
DAY 4 Legs
DAY 5 Pull
DAY 6 OFF
DAY 7 OFF
DAY 1 Push
DAY 2 Legs
DAY 3 OFF
DAY 4 Pull
DAY 5 Push
DAY 6 OFF
DAY 7 OFF
Etc.
Or do lo stress beach work on day 4
DAY 1 Back (lats, traps, rhomboids, rear delts, lower back)
DAY 2 Pectorals/Deltoids
DAY 3 OFF
DAY 4 Legs
DAY 5 Biceps/Triceps/Abs
DAY 6 OFF
DAY 7 OFF
I would keep volume as low as possible to hit all the muscles correctly. Doing too much volume, further depleting muscle glycogen could actually make it harder to maintain muscle mass.
I would have 1 or 2 big lifts per session, trained for strength. I like the 5-4-3-2-1 sets/reps scheme (increasing weight on every set) but really Doing 10-15 reps/exercise in the 80-92% range with pretty much sets/reps scheme will work.
I would only do isolation/supplemental work for you weaker muscles (those that tends to atrophy more when you diet down).