Watts to kg calculation
How do you do it? I can't seem to find an answer...
If my FTP is 187 and I'm roughly 125-127 pounds, what is my watts/kg ratio?
Is it as simple as 187/125lbs (whatever that conversion is to kg)?
And there is so much that is dicussed about this-but what is the ideal number to shoot for? Seems everyone's idea of "ideal watts/kg" varies...
Thanks, sorry if this is already somewhere else but I can't find it.
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Comments
watts per kilo = 187 / 57 = 3.3 W/kg
For most of the talk around here, you'll hear discussions of watts at FTP per kg of body weight, and 4 is considered pretty top notch in triathletes. 3.3 is very solid.
Bike racers might get interested in W/kg at other power measurements (like 5min power, or 1min power), but these aren't that helpful for us.
Mike
Mike answered your question but here's the math...
There are 2.2 kilograms in a pound. Simply divide your weight in pounds by 2.2, so 125/2.2=56.8. Then divide your watts by your weight in kilos, so 187/56.8=3.29 wats/kg.
@Jeff - needless to say, I've thought about this a bit, and tried to research the question for our three sports. Joe Friel (who, after all, did write a book called Cycling Past 50), asserts that one should reduce expected pace or FTP by 0.5% per year after age 35. There is an article, written by a economist, entitled How Fast Do Old Men Slow Down, which looked at top marathon times by age, and found a lesser drop off, on the range of 0.2% per year. until the early 60s, when things started to go south faster. Another study looked at individuals over time, and followed their 5K (or maybe it was 10K) times from age 19 until ... whenever. They found race times would fall (get faster) from age 19 until about age 29, and then slowly rise, but would not return to the level at age 19 until age 64!
Finally, I can offer my own experience, FWIW. I do not have data pre age 55, but in my late 50's, I had a w/kg of 4.0 (3.969696...) at my best. In my early 60s, before my accident, I was 3.75, and since then I am struggling to return to 3.5 (currently 3.0, but I'm in my 7th week of OS after three months of not riding.) I can tell a similar tale about my swimming and running, so I feel good about the 0.2% drop off after about age 35-39, and then 0.5% after age 60-62.
My conclusion is that one should expect solid potential performance up until about age 57, then start to see a progressive deterioration, than maybe a faster fall as one enters Social Security/Medicare age. The interesting thing is, I can still train just as "hard", but the results aren't the same!
Now I gotta go get on the trainer for today's intervals ...
I think the old theory of losing 0.5-1% per year after 35-40 yo is outdated. Al is probably a lot closer in smaller decrements in 40' and 50's increasing in 60's+.
2.2lbs per kg, not the other way around.
Yes, I wrote it backwards. I got the math part right.
Brian,
That's correct; decrease weight, increase FTP and you will see and increase w/kg ratio.
Gordon