+1. I came to running through boxing, initially. The added weight on the ankles just ends up pounding the soles of your feet. Short trail runs I’d use them. Not worth the payoff (there was a payoff, but nothing some weight work in the gym couldn’t top.) Vest is a better way to go to add muscle/“torque to the motor” but even that, for triathlon, seems like a waste.
I started running with weighted gloves as well. I wonder if anyone still does this in the boxing (or trail/tri) world. Keep you hands up, at least rib cage level, almost in a defensive stance while you run (with weights). Really helped my arm swing when I first started. In the ring I never dropped my guard, so it was a great muscle memory drill atleast! Now I do long distance trail runs and the hand held water bottles never bothered me… so I got that goin for me… which is good…
Anyway, good luck!