yes, they are smaller, aerobic, slow twitch muscle fibers. my endurence comment was more related to delivering oxygen to the muscle, but was sloppy. was waiting for someone to poke me over it :-)
smaller functional muscle fibre size is one of the reasons you will often see very svelte endurance athletes.
you can build both slow twitch and the 2 types of fast twitch muscle fibers simultaneously with well planned workouts, but dont worry too much about this. your body will adapt to whatever you train for, just keep a good mix of everything you have mentioned so far and your body will respond.
never neglect the cardio though. a resonable mix of HIIT cardio will add aerobic capacity without sacrificing muscle mass or size. your high rep. punches with 16oz gloves will take care of shoulder endurance.
congrats on the installation! had not heard about of these before, but makes sense. so many questions…
are we talking a 100% closed, pre charged system with both units charged - no drying or long prep needed? anything special to do between the compressor and the air handler on final connection? with supplied gear, how did everything work for you in routng lines and positioning the air handler and compressor units?
have been thinking of adding a minisplit to my server room as additional/failure-state cooling and would usually want to use a pro for the work, but this is intriguing.
again, nice detail oriented weekend work!