Fat:Muscle Gain/Loss Ratios for Cutting and Bulking?

[CanadianEric]

I am attempting to put a spreadsheet together to calculate how long it would take (i.e. how many cut/bulk cycles it would take) to reach x desired bodyweight composition.

I reason that I can roughly calculate how many cycles it would take to reach whatever desired BW composition if I have the approximate ratio values for Fat:Muscle gain/loss during cutting and bulking.

In other words, I have two questions and am looking for two answers:
1) how many units of fat will be gained for every unit of muscle gained during a BULK
and
s) how many units of muscle will be lost for every unit of fat that is lost during a CUT.

And yes, I have googled this. Surprisingly, there seems to be no clear answer to these questions even though I would expect that these ratios are exceedingly important to anyone who is serious about attaining optimal composition of bodyweight.

[CanadianEric]

I've attached an excel prototype of what I'm talking about.

Each column = either a CUT or a BULK cycle.
I entered the following parameters for the calculator:
BULK = +10lb BW (+5lb LBM, +5lb Fat)
CUT = -10lb BW (-2 lb LBM, -8lb Fat)

After 9 alternating cut/bulk cycles, the subject went from a starting composition of 175lb @ 17%BF to a final composition (after a cut) of 165lb @ 6%BF

As you can see, there are some pretty useful implications for a calculator like this one...BUT, the parameters for the ratio of Fat:LBM gain/loss are critical, and I'm not sure what to make them.

You can play around with the calculator by entering your current stats in the "start" column.

[TommyGun1988]

What period of time did the cut and bulk cycles take from start to finish?

[CanadianEric]

What period of time did the cut and bulk cycles take from start to finish?

Well, it is just a calculator those cycles are theoretical.

Let's say for the sake of argument though (in order to figure out what the ratios for fat:LBM loss/gain to input into the calculator) that the subject simply did a +500/day calorie bulk and a -500/day calorie cut, which would = approximately 10 weeks spent on each cycle.

[TommyGun1988]

Well, it is just a calculator those cycles are theoretical.

Let's say for the sake of argument though (in order to figure out what the ratios for fat:LBM loss/gain to input into the calculator) that the subject simply did a +500/day calorie bulk and a -500/day calorie cut, which would = approximately 10 weeks spent on each cycle.

I see. Could be a decent tool for noobs who dont fully understand etc. Take my measlies man

[dmacdonal9]

I am attempting to put a spreadsheet together to calculate how long it would take (i.e. how many cut/bulk cycles it would take) to reach x desired bodyweight composition.

I reason that I can roughly calculate how many cycles it would take to reach whatever desired BW composition if I have the approximate ratio values for Fat:Muscle gain/loss during cutting and bulking.

In other words, I have two questions and am looking for two answers:
1) how many units of fat will be gained for every unit of muscle gained during a BULK
and
s) how many units of muscle will be lost for every unit of fat that is lost during a CUT.

And yes, I have googled this. Surprisingly, there seems to be no clear answer to these questions even though I would expect that these ratios are exceedingly important to anyone who is serious about attaining optimal composition of bodyweight.

Far too many variables (both environmental and genetic) to predict in this way. Search google scholar for "p-ratio" and "nutrient partitioning" if you're interested. Also see: http://www.bodyrecomposition.com/mus...ng-part-1.html

By the way, I would suggest you're approaching the basic idea too simplistically. It's not a given that muscle is lost on a cut, nor is it absolutely true that fat is gained on a "bulk". My opinion is that the influence energy intake has on training intensity, hormone production, and adaptive thermogenesis (BMR) is actually far more important than the pure energy cost of muscle protein synthesis (assuming adequate protein intake). In other words, I believe energy availability is not the rate limiting ingredient in MPS, so you can't really construct a model on that premise.