I am definitely training around or above lactate threshold during many of the intervals. The longer rows are at steady state, possibly with some LA+ accumulation if I sprint at the finish.
This is dependent on your goals. Losing/gaining weight or eben maintaining.
If you are trying to cut some fat while doing this then ditch the carbs and stick with the protein or simply water. If you are maintaining or bulking go for the carb, or carb and protein combo.