depends on what im training for. Ill preface with i shoot in the desert with nobody around.
If im "tactical rifle" training AKA barricades and reloads from concealment, shit like that then yes, battle belt and plate carrier since if im rolling tacticool ill have it all on.
If im training for comp shooting/EDC then no, just my comp shooting belt or IWB holster and reload where i actually keep it, i love when people carry IWB but on train OWB or carry a pocket mag but train in mag holsters..
If im doing cardio shoot training then depends on how i feel. I have bene trying to get into better shape so been doing alot more cardio drills and may pickup ar500 plates for my backup carrier just for the extra weight. But basically doing drills with much more running IE 25 50 75 and 100 yard cones, start at target sprint to 25 turn engage sprint to 50 etc. or a 10 (pistol) 20 (rifle) yard gap between cones in a square. targets 15 yards+ off the front of the square, sprint around the square engaging target with 1 round at each square until my legs say im too fat to deal with the BS. usually download mags and work reloads as well.