I totally disagree. By working to a level that high you will burn muscle as a fuel and will hinder all your muscle gains emensly. The idea here is to burn a few excess calories, not your entire muscle structure. Why are long distance runners and such like so skinny? Because they burn on a high level for long periods.
Working to a level of 55-60% of your maximum heart beat has been prove (will now try and find a study on this for proof) to be the most efficent level to work to to optimise fat cells as a fuel source rather than muscle.