Fat loss challenge at my gym

slbbw

My gym is doing a fat loss challenge for January and the owner asked for my opinion on the most fair way to calculate across old young male female etc.

So he definitely want to use BF% and will be using a handheld bio-impedance for the measurement. Obviously the accuracy of this device is debatable, but using the same device at the relative same time of day should at least be able to get an accurate trend.

So the question is how to make it fair. Is just calculate BF% difference between start and end of month enough, or is there a calibration that is needed. Does it need to be a percentage loss? or should it subtract the minimum BF% for men and women? Account for age?

CSARdiver

Accuracy in this case isn't as relevant as precision. To be as precise as possible measurements should be taken early in the morning post-voiding and pre-eating/drinking.

The impact of age is going to be minimal and any attempt to correct bias is much more likely to create bias.

Depending on the variance of participants a percentage loss would be the most "fair".

PAV8888

Can't be done (fair)

The more available fat you have to lose, the more favorable your expected fat to lean mass lost.

About the most fair you could get would be to separate men and women and again into categories (cat 3, 2, 1 obese, overweight lots, mid, low, high normal, mid normal, low normal weight), and have a competition of percent change within the categories.

Which could easily be gamed by water weight manipulation by someone who wanted to win.

So there's that.

NovusDies

PAV8888 wrote: »

Can't be done (fair)

The more available fat you have to lose, the more favorable your expected fat to lean mass lost.

About the most fair you could get would be to separate men and women and again into categories (cat 3, 2, 1 obese, overweight lots, mid, low, high normal, mid normal, low normal weight), and have a competition of percent change within the categories.

Which could easily be gamed by water weight manipulation by someone who wanted to win.

So there's that.

And there is always the chance someone like me could enter the competition and win simply because over the holidays I will likely balloon up 10 plus pounds of water that will come back off in January. I was recently attending some local wl meetings for the social aspect of it and I won 3 different achievement titles in about 5 weeks. I, of course, refused to accept anything when I knew most of it was not fat and instructed them to pass it down to the next in line. It caused confusion and I wasn't getting anything out of it so I stopped going.

MikePTY

There's never a good way to have these competitions. Better to just focus your individual goals and not try to compete with others progress.

4legsRbetterthan2

I would at least do different gender and age classes to make it more achievable for different groups, they can feel like they are competing against people they have a chance against.

BuiltLikeAPeep

I know this probably won't work for the thinner participants, I'm just throwing the idea in- but what about percentage of inches lost?

kshama2001

BF is easily manipulated but since the owner is probably going to run this challenge regardless, I would recommend a % lost.

mom23mangos

So when we did a family bet, I based it on % of goal met. But that meant that technically everyone could be a winner. Everyone picked a different goal. For my husband, son and his GF I think they picked something like 25lbs which was reasonable considering they are all technically obese. I picked 10lbs or 5% BF reduction. We all put in money and the pot would be split by whoever achieved their goal in the timeframe or else the person who got the closest. I kept a running tally of % of goal complete to see who was in the lead.

Duck_Puddle

I don’t think there’s a fair way to do it.

But based on the way those devices measure (and my Bf% “changes”), I would suggest the best strategy is to go in for the initial measurement very dehydrated, at a low point for weight (lower denominator, higher %, plus less water leads to falsely high readings)

The day before the final measurement, eat very heavy (literally) carbs and enough salt to kill a horse. You will bloat up like a blimp-but your measured BF% will be much lower (because your weight will be higher (higher denominator - lower %) and more water causes falsely low readings). I do this weekly-“lose” 3-4% BF overnight when I “gain” 4-12 pounds of water & food.

Percentage of body weight lost would be at least a reliable measurement (although would still bias against those with lower weight- but slightly less than BF).

sgt1372

No BF% measurement device is completely consistent or reliable - there's always some degree of error, even for DEXA and hydro which are the best of the bunch and electrical impedance devices the worst.

IMO, the best way to measure "fat loss" for the competition would be to use the change in BMI or the % of wt lost during the competition using the same scale to weigh all of the contestants at the start and finish and, in the case of BMI, the same height measurement device (or just marks) located somewhere posted on a wall in the gym.

Ideally, the scale would be the type you find at a doc's office that has a means of measuring both your wt and height built into it.