Sinclair’ s Bodyweight Correction formulaThe following is a follow up on my Community post “Age adjustments for lifting weights: comparisons and 1RM “: https://community.wolfram.com/groups/-/m/t/2386842
Sinclair’ s Bodyweight Correction formulaThe following is a follow up on my Community post “Age adjustments for lifting weights: comparisons and 1RM “: https://community.wolfram.com/groups/-/m/t/2386842
Below I add some comments on Sinclair’s Bodyweight correction formula.
But first we need the definitions of age adjustments and 1RM calculations for some of the examples.
But first we need the definitions of age adjustments and 1RM calculations for some of the examples.
In[]:=
coeffs={{30,1},{31,1.016},{32,1.031},{33,1.046},{34,1.059},{35,1.072},{36,1.083},{37,1.096},{38,1.109},{39,1.122},{40,1.135},{41,1.149},{42,1.162},{43,1.176},{44,1.189},{45,1.203},{46,1.218},{47,1.233},{48,1.248},{49,1.263},{50,1.279},{51,1.297},{52,1.316},{53,1.338},{54,1.361},{55,1.385},{56,1.411},{57,1.437},{58,1.462},{59,1.488},{60,1.514},{61,1.541},{62,1.568},{63,1.598},{64,1.629},{65,1.663},{66,1.699},{67,1.738},{68,1.779},{69,1.823},{70,1.867},{71,1.91},{72,1.953},{73,2.004},{74,2.06},{75,2.117},{76,2.181},{77,2.255},{78,2.336},{79,2.419},{80,2.540},{81,2.597},{82,2.702},{83,2.831},{84,2.981},{85,3.153},{86,3.352},{87,3.58},{88,3.843},{89,4.145},{90,4.493}};Transpose[coeffs];ageCoeffs=Thread[%[[1]]%[[2]]]//Association;brzycki[weight_,reps_]:=weight*(36./(37-reps))epley[weight_,reps_]:=0.033*weight*reps+weight;epley2[weight_,reps_]:=weight(1+reps/30.);oconner[weight_,reps_]:=weight*(1+0.025*reps);lombardi[weight_,reps_]:=weight*reps^0.10;mcglothin[weight_,reps_]:=100*weight/(101.3-2.67123*reps);wathan[weight_,reps_]:=100*weight/(48.8+53.8Exp[-0.075*reps]);oneRM[weight_,reps_,age_:30,method_:epley]:=Module[{rm=method[weight,reps]},{rm,rm*ageCoeffs[age]}]
In[]:=
myAge=64(*asofwriting,soon65*)
Out[]=
64
Sinclair' s Bodyweight Correction formula"The Sinclair Coefficients for the Olympiad January 1, 2017 to December 31, 2020 For Men's and Women's Olympic Weightlifting""" "The details about the formula http://www.iwf.net/downloads/?did=993 http://www.iwf.net/downloads/?did=994" ""The Answer to the question "What would be the total of an athlete weighing x kg if he/she were an athlete in the heaviest category of the same level of ability?" is given by the formula : Actual Total x Sinclair Coefficient = Sinclair Total"" "via http://www.iwf.net/downloads/?category=68 via http://www.mastersweightlifting.org/formulas.html
In[]:=
(*bodyWeightinkg*)sinclairCoeff[bodyWeight_,gender_]:=Module[{A,B,X,coeff},A=If[gender=="male",0.751945030,0.783497476];B=If[gender=="male",175.508,153.655];X=Log10[bodyWeight/B];coeff=If[bodyWeight<=B,10^(A*X^2),1];coeff]
Some examples
I continue with my 117kg x 1 PR in deadlift.
Since I weighed 76 kg when lifted this, it has a Sinclair coefficient of 1.25703.
I continue with my 117kg x 1 PR in deadlift.
Since I weighed 76 kg when lifted this, it has a Sinclair coefficient of 1.25703.
In[]:=
w=117;(*1repdeadliftinkg*)sinclairCoeff[76,"male"]
Out[]=
1.25703
This means that it corresponds to a 151.9kg lift by “an athlete in the heaviest category of the same level of ability”.
In[]:=
epley[117,1]*sinclairCoeff[76,"male"]
Out[]=
151.926
Since the Sinclair coefficient don’t care about age, I multiply with the Epley’s age adjusted coefficient (see link above for more about this). Perhaps this is stretching the mathematics a little too far, but then it would mean that it corresponds to a lift of 247.5kg (by “an athlete in the heaviest category of the same level of ability” aged 30).
In[]:=
epley[117,1]*ageCoeffs[64]*sinclairCoeff[76,"male"]
Out[]=
247.488
Here’s another example. We meet S again (from the other notebook).
S took 77kg x 5 in bench press when he was 37 years old weighing 90kg. How much would I have lift x 5 when 60 years old and with a body weight of 76kg? I would have to lift 51.3kg.
Let’s first ignore the age part and just look at the body weights. I would have to bench press 70.9kg x 5 in order to match him given our different body weights.
S took 77kg x 5 in bench press when he was 37 years old weighing 90kg. How much would I have lift x 5 when 60 years old and with a body weight of 76kg? I would have to lift 51.3kg.
Let’s first ignore the age part and just look at the body weights. I would have to bench press 70.9kg x 5 in order to match him given our different body weights.
In[]:=
Solve[epley[x,5]*sinclairCoeff[76,"male"]==epley[77,5]*sinclairCoeff[90,"male"],x]
Out[]=
{{x70.8608}}
And now let us add adjustments as well: I would have to bench press 51.3kg in order to match S given our ages and body weights.
In[]:=
Solve[epley[x,5]*sinclairCoeff[76,"male"]*ageCoeffs[60]==epley[77,5]*sinclairCoeff[90,"male"]*ageCoeffs[37],x]
Out[]=
{{x51.2968}}