Difference between revisions of "Predicting maximal strength"
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* W. Kemmler, D. Lauber, J. Mayhew, and A. Wassermann: "Predicting Maximal Strength in Trained Postmenopausal Woman", ''Journal of Strength and Conditioning Research'' 20(4), (2006), pp. 838-842. | * W. Kemmler, D. Lauber, J. Mayhew, and A. Wassermann: "Predicting Maximal Strength in Trained Postmenopausal Woman", ''Journal of Strength and Conditioning Research'' 20(4), (2006), pp. 838-842. | ||
+ | |||
+ | === The underlying JavaScript code === | ||
+ | <source lang="xml"> | ||
+ | <jsxgraph width=700 height=500> | ||
+ | var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-1,1.8,30,0.8]}); | ||
+ | bx = brd.createElement('axis', [[0,0.9], [1,0.9]], {}); | ||
+ | by = brd.createElement('axis', [[0,0], [0,1]], {}); | ||
+ | |||
+ | var w = brd.createElement('slider',[[24,0.92],[24,1.7],[0,50,200]],{name:'weight w',snapWidth:1}); | ||
+ | |||
+ | f = function(x){ return (0.988+0.0104*x+0.00190*x*x-0.0000584*x*x*x); }; | ||
+ | |||
+ | var c = brd.createElement('functiongraph',[ | ||
+ | f, | ||
+ | 1,22 | ||
+ | ], {strokeColor:'black', highlightStrokeColor:'black'} | ||
+ | ); | ||
+ | |||
+ | var r = brd.createElement('glider',[10,1,c],{name:'',fillColor:'black',strokeColor:'black',style:6}); | ||
+ | var t = brd.createElement('text',[function(){return r.X()+1;}, | ||
+ | function(){return r.Y();}, | ||
+ | function(){return "repetitions r = " + Math.floor(r.X());}]); | ||
+ | |||
+ | brd.createElement('text',[5,1.6, | ||
+ | function(){return "predicted 1RM = " + (w.Value()*f(Math.floor(r.X()))).toFixed(2);}], | ||
+ | {fontSize:'24px',strokeColor:'red'}); | ||
+ | |||
+ | </jsxgraph> | ||
+ | |||
+ | </source> | ||
[[Category:Examples]] | [[Category:Examples]] |
Revision as of 15:49, 13 August 2009
This little application tries to predict the maximal strength (1RM) based on a repetitions to fatigue (RTF) value.
The calculation is based on the so called KLW formula:
- [math] 1RM = w\cdot(0.988+0.0104\cdot x+0.00190\cdot x^2-0.0000584\cdot x^3) [/math]
The horizontals axis denotes the number of repetitions, the vertical axis denotes the ratio 1RM/RTF.
References
- W. Kemmler, D. Lauber, J. Mayhew, and A. Wassermann: "Predicting Maximal Strength in Trained Postmenopausal Woman", Journal of Strength and Conditioning Research 20(4), (2006), pp. 838-842.
The underlying JavaScript code
<jsxgraph width=700 height=500>
var brd = JXG.JSXGraph.initBoard('jxgbox',{boundingbox:[-1,1.8,30,0.8]});
bx = brd.createElement('axis', [[0,0.9], [1,0.9]], {});
by = brd.createElement('axis', [[0,0], [0,1]], {});
var w = brd.createElement('slider',[[24,0.92],[24,1.7],[0,50,200]],{name:'weight w',snapWidth:1});
f = function(x){ return (0.988+0.0104*x+0.00190*x*x-0.0000584*x*x*x); };
var c = brd.createElement('functiongraph',[
f,
1,22
], {strokeColor:'black', highlightStrokeColor:'black'}
);
var r = brd.createElement('glider',[10,1,c],{name:'',fillColor:'black',strokeColor:'black',style:6});
var t = brd.createElement('text',[function(){return r.X()+1;},
function(){return r.Y();},
function(){return "repetitions r = " + Math.floor(r.X());}]);
brd.createElement('text',[5,1.6,
function(){return "predicted 1RM = " + (w.Value()*f(Math.floor(r.X()))).toFixed(2);}],
{fontSize:'24px',strokeColor:'red'});
</jsxgraph>