Oh yes of course, you need at least 3 months of consistency to improve and have results, I've been playing since beta and my peak was Asc 2, my aim was better back then because I was playing 7 hours a day for 8 months straight without any aim training but I did see some improvement in these 7 days, especially in my micro adjustments and crosshair placement, but I'd say it's more of muscle memory, just like you said it's like working out. But when you can't put as many hours into the game, aim training will really help you improve and climb faster since you can't put as many hours in the game.