Question: what is the difference between the brooks adrenaline 19 and 20?
Answer: Brooks Adrenaline GTS 19 vs 20: Brooks has kept the midsole and outsole from the 19, so the 20 feels pretty much identical to the 19. The more flexible foam gives you a little better transition and you feel a little lower to the ground, but at times can feel like a little less shoe when compared to the 18.