JS

Those are interesting questions, some of which I don't know the answers to! The short answer, of course, is "it depends on your goals"...whether you're hoping to attain maximum performance for a single effort, increase your aerobic base, or train for general health. "Train in the energy system you want to improve." That might actually be a good article, someday...

JS

Love your articles--well-written, well-referenced, and super informative.

Out of curiosity, do you take requests? If so, I would be very interested in more on the topic of metabolic flexibility, specifically some discussion of fed vs. fasted training, how different types of exercise affect metflex, how post-workout "refueling" fits into the whole picture, that sort of thing.

Not sure if this is worth a whole article of your time. If not, could you or other members point me towards some other resources?

Thanks so much!