Hi ScottyP,
The short answer is: Mostly. You should stop eating carbs during low-intensity training. But not all training, not strength training or higher intensity efforts whether they be intervals, uphill water carries, etc. Those workouts should give you enough opportunity to test your tolerance to the GU and blocks.

Here is more info:

Train to Burn Fat

Or type ‘fat’ into the search box in the top right corner of the page.
Thanks for writing in.
Steve