

Treadmill Performance Predicts Mortality - forloop
http://www.hopkinsmedicine.org/news/media/releases/treadmill_performance_predicts_mortality?utm_content=bufferfe7a5&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

======
rpackard
I am really interested in how this is measured. I have found this info on free
sources so far

"The FIT Treadmill Score, calculated as [percentage of maximum predicted heart
rate + 12(metabolic equivalents of task) – 4(age) + 43 if female]"

And this from another interview.

"In addition to age and gender, the formula factors in peak heart rate reached
during intense exercise and the ability to tolerate physical exertion as
measured by so-called metabolic equivalents, or METs, a gauge of how much
energy the body expends during exercise. More vigorous activities require
higher energy output (higher METs), better exercise tolerance and higher
fitness level. An activity such as slow walking equals two METs, compared with
eight for running."

If anyone has access to the paper and could better show the algorithm I would
be super thankful.

EDIT: I think I figured out more but still not positive about MET unless the 2
for if heart rate hit max walking and 8 for if heart rate hit max with
running. [(Measured Heart Rate Max/(220-age)) _100 + 12_ MET - 4*age + (43 if
female)]

~~~
lucaspiller
So basically the closer your actual maximum heart rate when excersising vs
your age estimated maximum heart rate[0] the healthier you are.

[0]
[http://www.runningforfitness.org/faq/hrmax](http://www.runningforfitness.org/faq/hrmax)

~~~
mrfusion
I'm confused though because as you increase your endurance your heart is able
to get more oxygen to your body while beating slowing. For example the heart
rate of a marathon runner's first mile might not look much different than you
or I going on a walk.

~~~
msandford
They stress you to the point of maximal exertion. This will favor fit people
for a couple of reasons.

1\. The fitter you are the more experience you have working through the pain
of maximal exertion and the closer you can get to your true max

2\. The fitter you are the better shape your heart is in and the easier it is
to break your age estimated max heart rate

When I was 25 I rode competitively for my university in grad school. Max heart
rate prediction is 220 - age so my theoretical max was 195 but I routinely saw
numbers above 200 and occasionally above 205 and a few times over 210.

Further the metabolic equivalent is what really does the correction. If your
heart rate hit max at a brisk walk you don't get very many bonus points; if it
hits max at a run you get a lot of bonus points (past your heart rate) and
your score goes up considerably.

~~~
mrfusion
That's interesting. I always figured the max heart rate by age was just a
recommendation. But you're saying the max heart rate actually decreases as you
age? What would cause that?

So I guess it's good I can get 5 bpm above my age max but bad that a 6MPH jog
for 5 minutes is all it takes?

~~~
frogpelt
My guess is that the heart is a muscle and just like other muscles it tends to
not have as much output as you age.

~~~
msandford
I actually suspect that it has less to do with your heart and more to do with
your fitness. People generally get less fit as time goes on and thus the
target heart rates reflect that. I rode with one guy who was in his 50s and
could still hit 190ish no problem (while outriding us college kids), mostly
because he was monstrously fit.

If your muscles are able to do less as you age (and that I definitely
believe!) then it's easy to see that it's harder to produce the same amount of
power. As the power requirements on your heart decrease it slows down. So for
a younger guy who can make 1000 watts peak his heart rate might be 210 to do
so. An older guy might only be able to make 800 watts peak and have a heart
rate of 180 for that amount of power.

------
jdc
Compare with:

Prognostic Value of Treadmill Exercise Testing
[http://circ.ahajournals.org/content/98/25/2836.long](http://circ.ahajournals.org/content/98/25/2836.long)

Maximal Exercise Testing Variables and 10-Year Survival Fitness Risk Score
Derivation From the FIT Project
[http://www.mayoclinicproceedings.org/article/S0025-6196(14)0...](http://www.mayoclinicproceedings.org/article/S0025-6196\(14\)01136-7/abstract)

~~~
Someone
Also, from the Christmas edition of the British Medical Journal (where
somewhat serious articles with a funny side are a tradition):

*"How fast does the Grim Reaper walk? Receiver operating characteristics curve analysis in healthy men aged 70 and over"

([http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3240682/](http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3240682/))

------
dceddia
"What does it say Moss, does it say I'm already dead?"

"Oh, no, that'd be terrible."

"Oh thank--" "It's Thursday."

~~~
kurokikaze
"The results are in. Yep, you're mortal."

------
slagfart
Does anyone have a link to the chart described at the bottom of the article?

~~~
ISL
Not sure if it's globally visible, but the paper is here:

[http://www.sciencedirect.com/science/article/pii/S0025619614...](http://www.sciencedirect.com/science/article/pii/S0025619614011367#)

Figure 1 is the money plot. In short, FIT scores below 0 show survival
percentages that drop roughly linearly from ~90% down to 25% at a FIT of -200.
Above a FIT of 0, survival percentages rise roughly linearly to near 100%.

TL;DR: you want your FIT score to be better than 0.

~~~
jsprogrammer
You do not have access to the content that you requested. Please review your
options for gaining access at the bottom of the page.

------
nate112358
Correlation is not causation. since this study is not experimental we can't
assume that increasing your FIT score will improve mortality.

~~~
mfringel
Completely correct.

"Correlation" and "causation" are spelled differently, and have different
numbers of letters.

------
testingonprod
There are probably a ton of confounding variables at play here that aren't
being accounted for.

~~~
kiers77
damn straight. take this "paper" with a pinch of salt!

