BodyPump is total body, high repetition strength training. I think the class is great. I taught the class many years ago, but now I try to take the class 2 times per week. The squats, lunges and core work will help with running. The upper body exercises help to keep you balanced.
This class is designed to be done with BodyFlow/BodyBalance which is yoga, Pilates core and stretching which so important to stay healthy with running.
The problem is trying to fit it all in with training. When I was training for the marathon, I did BodyFlow every week (I teach) and BodyPump once or twice. The weeks of the longest runs of 18-20 miles, I would skip the strength and just recover. Then during the taper, I added the strength back in.
I have to strength train while running or I get overuse tendonitis very easily. The resistance exercises keeps my muscles strong and joints stable.