Luke can you tell me how much bigger a 17 inch arm is to a 18 and to a 19 and too a 20. Whats the maths?
Just a ratio of the squares...
Circumference = 2pi x radius
radius = Circumference/2pi
Area = pi x (radius)
2 = pi x (Circumference/2pi)
2Ratio of two upper arm cross-sectional areas: Areas1/Area2 = (pi x Circumference1
2)/4pi
2 ...divided by... (pi x Circumference2
2)/4pi
2 ...sorry I can't do a proper equation with this text editor.
Cancel all the identical terms above and below: Area1/Area2 = Circumference1
2/Circumference2
2 ...it doesn't matter if you measure in inches or centimetres or parsecs.
So:
...to go from 14'' to 15'' you have to increase your upper arm 14.8% ...because 15
2/14
2 = 225/196 = 1.148 = 14.8% increase
...to go from 15'' to 16'' you have to increase your upper arm 13.8%
...to go from 16'' to 17'' you have to increase your upper arm 12.9%
...to go from 17'' to 18'' you have to increase your upper arm 12.1%
...to go from 18'' to 19'' you have to increase your upper arm 11.4%
...to go from 19'' to 20'' you have to increase your upper arm 10.8%
...to go from 20'' to 21'' you have to increase your upper arm 10.3%
...to go from 21'' to 22'' you have to increase your upper arm 9.8%
...to go from 22'' to 23'' you have to increase your upper arm 9.3%
...to go from 23'' to 24'' you have to increase your upper arm 8.9%
...so while it may seem that it gets easier and easier to increase arm size, remember those are slightly decreasing percentage increases of an ever escalating bodyweight. Bodyweight increases faster than the incremental percentage increase in upper arm cross-section. You gotta get much bigger to add an inch to your arms.
Compare the difference between a 15'' arm (able to curl 100 lbs) and a 24'' arm: a 156% increase
Assuming direct strength correlation, a 24'' arm should be able to curl 250 to 300 lbs strictly... how may of these 24'' armed pros can actually do that?
Now let's consider a simple direct relationship between arm size and lean bodyweight using those crude percentages, maybe it might work:
15'' arm assumed to be 150 lbs of solid muscle ...everyone can agree with this, it holds for most average build average height non-trainers
16'' arm would go with 171 lbs ...which surprisingly matches most middleweights mass/measurement ratio
17'' arm would go with 193 lbs ...which surprisingly matches the mass/measurement ratio for most 202 competitors, and Franco Colombu
18'' arm would go with 216 lbs ...which surprisingly matches the verified mass/measurement ratio for most 1970s competitors
19'' arm would go with 241 lbs ...which surprisingly matches Schwarzenegger's verified mass/measurement ratio
20'' arm would go with 267 lbs ...which surprisingly matches Dorian Yates' verified (offseason '93) mass/measurement ratio
21'' arm would go with 294 lbs ...which surprisingly matches Lou Ferrigno's verified mass/measurement ratio
22'' arm would go with 323 lbs ...which surprisingly matches Ronnie's VERIFIED mass/measurement ratio
...do we dare to extrapolate a little further after all this direct correlation showing just how right the math is?
23'' arm would go with 353 lbs ...a measurement claimed by a contest ready 225 lb Flex Wheeler (oh borther)
24'' arm would go with 384 lbs ...the measurement you tools ascribe to Ronnie Coleman: 384 lbs at about 10% bf
Hope this explains my reasoning to all those interested. I'm not pulling numbers out of my ass... these simple ratios (with some minor corrections) not only hold for humans, but also for our closest relatives: chimpanzees; orangs and gorillas.
There are occasionally the odd mutant with unusual proportions/attachments who can measure a full inch or so outside of the scale (Lee Priest comes to mind: 21.5'' arms at 240 lbs) but such deviations are so obvious that the physique is seemingly dominated by the upper arms (Priest is obviously somewhat dwarfed and "all arms" for example).
NO ONE... repeat NO ONE... no one measures 2'' outside the scale... it just doesn't happen.
You guys have all been brainwashed by FLEX Magazine's policy of instilling unrealistic expectations in teenage boys.
Don't believe the hype.
The Luke
(sorry for the long post)