Glycogen is maintained and replenished during ketosis. page 9

[Owly]

Right on. But for those who wish to operate in a state of ketosis the carb levels are still low enough that they burn through it all very quickly and get into that ketogenic state regardless. This will be easier to do if you are a very high level athlete, of course.

But one of the things that's been noted about ketosis for people like endurance athletes is that it's useful to be able to run on fat as well as carbs during the race, but you don't have much sprint power once the glycogen burns out. That's fine if you just want to get through the race, but if you are competitive and want to be able to put on the jets at the end, you're going to need some carbs because you simply can't generate enough through gluconeogenesis rapidly enough to be able to fuel that burst at the end of the race.

[Owly]

Low intensity steady state type of activities without any anaerob work, or low rep weight training depending on ATP will not be to different in ketosis. Perhaps some activities may be even better, like shooting, golf or pool etc.! But try some high volume weightraining next time you goes to the gym in ketosis, short breaks, high reps and high sets. That's really sucks...

Even my heavy, low-rep lifting was not good on VLC.

[Drumroll]

But one of the things that's been noted about ketosis for people like endurance athletes is that it's useful to be able to run on fat as well as carbs during the race, but you don't have much sprint power once the glycogen burns out. That's fine if you just want to get through the race, but if you are competitive and want to be able to put on the jets at the end, you're going to need some carbs because you simply can't generate enough through gluconeogenesis rapidly enough to be able to fuel that burst at the end of the race.

It may effect your results at the end of the race, yes, but consider this...

If you can sprint to the front of the pack at the beginning of the race and then have fat burning kick in to fuel you and provide the steady energy you need to maintain your lead, you may not NEED that extra sprint at the end. Again, this is just a hypothesis, and it may not work for everyone who tries it.

Experimentation, especially for athletes, will lead them to find which state is the most efficient for them to be in. It will be different for everybody.