Recovery is definitely tied for the most important factor affecting performance in the gym and out in the arena or on the field next to practice/training itself.
One of the main goals for anyone that spends time in the gym is to gain muscle. I find that a lot of people believe that to gain more they have to workout more. While there can be some truth to this belief, it does come with a big caveat: more training will lead to more gains ONLY when your body has the capacity to do so. What this means is, that in order for you to benefit from more training, a lot of stars have to align...do you sleep enough, do you eat right, are you functioning mentally, physically, and emotionally well, do your genetics support more training/muscle, are you on ergogenic aids that support more growth, etc.
You may have the strength to sprint a mile without stopping and then lift 400lbs off of the floor, but why can't you seem to sprint 1.5 miles and then lift 450lbs off of the floor