I wouldn't bother. As far as I know, you don't do your fit test in duty gear. The belt has too much potential for injury. Having had to run with weighted ruck-sacks and full duty gear, you may be surprised at the friction sores that you can get. Not to mention, you have to really be careful rapicly introducing that kind of weight into a training regiment of longer running.
I think you would be far better served by modifying your current running program. I would work in sprints (great for cardio and fast muscle twitch), ladders (200m, 400m, 800m, 1600m, 800, 400m, 200m... all run at an accelerated rate with rest in between), and sprinkle in a long, slow day (run non-stop for 60min at a pace where you could hold a conversation with someone).
Train smarter.
We bring evil things to evil people, kicking in a door near you!
."In theory, there is no difference between theory and practice. But,
in practice, there is."
- Jan L.A. van de Snepscheut
"The difference between 'involvement' and 'commitment' is like
an eggs-and-ham breakfast: the chicken was 'involved' - the pig
was'committed'."
-unknown
Working on a PhD in CQB one doorway at a time.
When the wolf attacks, he will find not all who run with the flock are sheep!