PA and hica both work via the mtor pathway somehow but in different ways than something like leucine does so since they have different moas they can be stacked. The question in all this is whether any of it becomes redundant like if you get diminiishing returns from trying to boost up mtor but nobody knows. Like in the soccer study for hica the soccer players were on a relatively high protein diet and the hica increased protein synthesis but if they had just taken in more protein and leucine it may have had the same results since the additional leucine might have had the same effect in terms of increasing protein synthesis.