This sounds quite scary to me. I would think that exercise is not something that goes at the expense of working, it might even increase productivity. Even if it's long walks outside. However, I don't have any references on this except for my very limited personal experience.
Read a little further. He has a special needs kid. I don't know how demanding that is for him but I do know that getting the worklife/homelife balance right and finding time to exercise can be quite a challenge even with regular kids.
And btw, I've read his blog for some time now. While I don't make all the same personal choices as he does when it comes to getting things done, I've found his reasoning-from-principles approach to it very helpful.
i thought the exercise bike he bought looked excellent, though. i'm tempted to get one so that instead of lying on the couch reading i can sit on the bike and get some exercise without having to devote singletasked time to it.
This sounds quite scary to me. I would think that exercise is not something that goes at the expense of working, it might even increase productivity. Even if it's long walks outside. However, I don't have any references on this except for my very limited personal experience.