T Nation

Metabolically Inflexible or Just Too Damn Active?

There are two different scenarios I find that just tank my energy levels,

  1. Whenever I try to apply nutrient-timing, i. e. have P+F meals until I train at which point I ingest carbs intra- and post-workout (I’ll see slightly better workout performance if I have a pre-workout meal with carbs)
  2. Have high-fat/low-carb days.

I’m curious as to if this is a consequence of me having poor metabolic flexibility or if my activity levels are high enough to require a larger carb intake. But I don’t know how to figure out which is the case.

Keeping calories equal, even in a deficit, a higher carb intake results in me just being generally more active (I’ll do pullups 9whenever able - among other things, my workout volume increases, my NEPA increases and my general pace throughout the day is generally higher).

At maintenance or a surplus I still experience a general sense of fatigue/lethargy when fats are kept higher and overall I seem to fare best at just eating balanced meals at every meal - potentially coming in a bit too low on fats for it to be considered ideal.

As a mere curiosity, is there a way to determine if you are metabolically inflexible? I mean, I know what makes me feel and perform the best so obviously that’s what I should be doing even if it’s not optimal from a theoretical standpoint (insulin resistance anyone?)

My daily activity levels are usually 5km on bike, 5 flights of stairs, 10k steps + a weightlifting workout or a climbing session. And that’s more of a lower bound.

Your responses to nutrients sounds very typical, and your activity level is good.

There was some discussion a while ago in one of the keto threads about the time frames of becoming food source adapted. It takes some time. Until that happens, you won’t have the energy to feel normal and perform well.

I’ll @mertdawg and @KennyCrox for you because they’re like titans on this subject.

1 Like