Really what is so hard to understand? If you have played competative sports before its pretty obvious, if not, well I guess it isn't so obvious.
Its in game shape not just in shape. You get it by playing in games, not practice and not by training for a marathon. Unless he had the opportunity to play in 48 min basketball games with nba bball players you aren't going to be in shape. Not to mention that pierce was completely out with an injury anyway.
Yeah, there are two different types of "game shape".
One is conditioning. I tend to agree that there's no legitimate excuse for a healthy player to be fat and/or sucking wind on the court. If they had to recover from injury during the off-season, fine, but otherwise their conditioning should be there.
Yes, I was primarily referencing this, and we've seen quite a number of winded players during Nov/Dec time frames.
And even a person, with an injured leg can use one of those seated arm bicycles for cardiovascular.
The other type of "game shape" is more the mental aspect. Readjusting to the speed of the game, the timing, the instincts, etc. It seems like every season there's a lot of rust that needs to be knocked off, and I'm not sure that anything other than playing professional basketball prepares you for that.
This is where adjunct training, like martial arts, archery, fencing, etc, keep the mental juices following, along with the overall physical conditioning. Yes, there's always rust, along with the body simply not cooperating in tandem but the fact of the matter is that the mind-body connection can be trained and enhanced off season.
Here's a side note on that notion ... why hasn't Rondo gotten a hypnotist for his free throws? I guarantee that along with brain wave training (alpha/theta plus gamma), that Rondo's contribution on the stripe will go up. If your subconscious mind believes that you can hit free throws, you will hit free throws.