[Alleyfield]

I highly doubt the effectiveness of polyphasic sleep. I myself found myself physically fatigued when I tried something like that.

So, based on my own (little) experience, my muscles need the long rest that a good night's sleep gives.

And doing "something useful" while commuting... Well ain't there a sure sign for disaster?

Hmm. Now don't get me wrong, but your post seems to be coming from a guy who's heading enthusiastically straight into a total mental burndown...

[MichaelSalib]

I think the original commenter was envisioning a bus/train/van-pool/subway/ferry commute rather than a car/bicycle/walking commute. My last job involved a long subway trip and I found that a Kindle really helped. The trains were too crowded to make reading on, let alone working on a laptop feasible.

[Alleyfield]

I understood that he meant being in a bus/train/van-pool/subway/ferry. The point that I was trying to make was that trying to do "something useful" while commuting is, at least to me, pretty annoying - there's so much distraction going on around you that your chances of actually having attention to the task you're doing are slim.

And time without attention is time wasted.

Ultimately you might find yourself using 24/7 of your time in practicing things - and realizing that you've understood nothing.

And then you're ready to welcome the burnout

[drKarl]

Yes I meant a bus/train/van-pool/subway/ferry, and yes I was thinking in listening to an audiobook/podcast, reading a book, perhaps doing some brainstorming with a Moleskine (well, it depends on the crowdiness of where your are), and if you have a table perhaps working on your laptop...

[jasonlotito]

"And doing "something useful" while commuting... Well ain't there a sure sign for disaster?"

Podcasts and Audiobooks. You can learn new things, keep on on recent events, or, even better, just enjoy the time with a good book. You can do this while driving even, without problems.

The only downside is you tend to not mind the traffic during the commute.