Hi. Setting up antennas is one thing (VIXAM/NVIS etc) but you will be doing a lot more than just that - radio propagation theory, programming radios, voice procedure, crypto etc. so be prepared to take a lot notes. As far as the masts - VIXAM is the most difficult one. When you are doing your EC/PCs, do not walk between the guy lines as you will waste a bunch of time, as with all things Army - hustle and move with a purpose. Also, there is a trick with the red guy lines where you can save a bunch of time by checking the mid point of the red line and tightening it to hip height. This may not make sense now but should once you start doing them. I also like getting the mast pins all lined up before shooting the mast up - always gives me a straight mast and you can save time on having to adjust the white and blue lines that way. Better yet - you are allowed to line them up before the EC/PCs too. One thing I would always check - make sure the mast sections are sufficiently lubricated or at least are not jammed before the EC/PC - seen more that one test failure cause of that.
As for exercises and work out tips - the VIXAM can be shoulder intensive so my go to is always rounds of thrusters with running