You shouldn’t be neglecting cardiovascular work either; both HIIT and LISS each play a role in enhancing mitochondrial density, balancing neurotransmitters, improving oxidative capacity, and influencing brain plasticity. Q: Do I have to do cardio? A: Yes, as I touched upon in the last question, it would be ideal to include some high and low intensity options as each has physiological benefits. Q: Do macros matter? A: To put it succinctly, yes.