Here is a great feature from the show ‘Sport Science’, talking about the myth of warming up with a weighted implement.
In baseball, the pros still commonly use up to 16 oz. of extra weight in the form of a ‘donut’ slid onto the barrel of the bat. After swinging this several times, your regular bat will feel lighter and faster. I remember this phenomenon from little league.
The same holds true in golf. If you are warming up with two clubs at the beginning of a round, you will be putting yourself at a huge disadvantage – watch:
This video discusses a short term warmup effect, but these principles hold true over the long term as well for building speed and distance.
Chances are that when you train with a super heavy training driver ( there are several on the market), you will gain little or no speed with your own driver, and you will be learning a completely different motion. Or even worse, your contact will suffer just like you saw on the video. Nothing is worse for driving distance than missing the sweet spot! The golf swing is a highly specific and coordinated motion, so the training must be similar if you wish to get the best resutls.
So get rid of that super heavy training club – you’re learning a different sport with it! It will only make you go faster when you swing with that much weight. Sell it on Ebay to someone who hasn’t seen the science!