# Carb Cycling with Katch McArdle Formula

Carb Cycling with Katch McArdle Formulaand I was wondering of the numbers to cut bf I came up were on point. ** Furthermore, On my low days which will be on my off days; is it alright if i don’t necessarily hit the carb macro( Staying low) ? Can I incorporate IIYFM following the carb cycling macros ?

I used the Katch McArdle Formula, this is what I came up with.

370+(21.6x66.2)
370+(1,429.92)
1,7992.92~ 1,800

I’ll be training 5 days a week, therefore:

1,800x1.55= 2,2790… 20% decrease—> 2,232

-Moderate days: 219gProtein/183gCarb/69gFat
-Higher days: 219gProtein/229gCarb/69gFat
-Low Days: 219gProtein/137gCarb/69gFat

There are two separate issues to be considered. First is the use of the KM formula in calculating BMR. As you probably know, this formula is predicated on having an accurate estimation of LBM–if the estimate is off, the BMR calc is off, and if the BMR calc is off, the estimated deficit is off. So question one is, how did your LBM estimate of 66.2 come to be?

The other issue is the diet itself. You call it a ‘carb-cycling’ diet, but the carbs don’t vary all that much from day to day–less than 100 g’s difference between the High and Low days. How did you come to decide upon this particular constellation of macros?

I appreciate the response. I calculated my LBM with several online calculators. They were relatively in the same range. I weigh 166 with 12% BF. According to the calculators my LBM is 146 lbs.

Well I read the carb cycling codex,

So for protein I used 1.5Grams per pound and 1.25 for carbs and the remaining calories for fat. I think I screwed up on the carb macros. A 125% increase from the moderate days, the carbs for higher days should be 412Grams. As for lower carb days a 75% decrease would equal 46Grams.

Do those numbers make more sense or am I still wrong ?

Thanks a lot man.

I appreciate the response. I calculated my LBM with several online calculators. They were relatively in the same range. I weigh 166 with 12% BF. According to the calculators my LBM is 146 lbs.

Well I read the carb cycling codex,

So for protein I used 1.5Grams per pound and 1.25 for carbs and the remaining calories for fat. I think I screwed up on the carb macros. A 125% increase from the moderate days, the carbs for higher days should be 412Grams. As for lower carb days a 75% decrease would equal 46Grams.

Do those numbers make more sense or am I still wrong ?

Thanks a lot man.

First, unless you measured your BF via a reliable and accurate technique (eg, immersion; DEXA scan), I recommend you dispense with the BMR derived from the 12% estimate, and instead calculate your BMR based simply on your weight. BW x 15 is a good estimate for caloric needs on workout days; for you, this is ~2500. On rest days, BW x 12 (~2000) is your BMR.

So, as for setting up the macros: As you look around TN you’ll find all sorts of approaches. CT’s is fine (although I seem to recall him expressing dissatisfaction of late with that particular article). My personal preference is to countercycle fats and (to a lesser extent) protein along with the carbs–in other words, let fats go low when carbs go high, and vice versa. Something like:
High-carb day: Protein @1g/lb BW (or a little lower); Carbs @2.5g/lb (or a little higher); Fat @ incidental only. (This day’s caloric total should run about at BMR (ie, ~2500). This will help keep leptin from crashing.)
Medium-carb day: Protein @1g/lb (or a little higher); Carbs @1g/lb; Fat @ .5g/lb
Low-carb day: Protein @1.5 g/lb (or a little higher); Carbs @.5g/lb; Fat @ .5g/lb
No-carb day: Protein @1 g/lb (or a little higher); Carbs @ incidental only; Fat ~100g. (It’s important to have some high-fat days, as this helps supports hormone production.)

You would run 1 High, 2 Med and 2 Low days on your w/o days, and No-carb on the 2 rest days. Note that there is some built-in flexibility to allow you to tailor how much of a caloric deficit you want to run.

Carbs should be distributed centrifugally, centered on the peri-workout period. That is, the carbs on your low-carb days should be consumed in the peri-workout window; on medium days, in the peri-workout window + the immediately preceding and/or following meals; etc.

Because carbs promote AA uptake, protein intake need not be quite as high on the High-Carb day. (To paraphrase Shelby Starnes, carbs make protein more ‘available,’ therefore, a plenitude of carbs means less dietary protein is required.)