View Full Version : Single number for ride effort
WingNut 05-13-2008, 12:11 AM Just reading Joe Friel's trainingbible- he mentions a single number to reflect training effort, I know this is poss with a power meter, but for those of us with a HRM how about calories? it will take into account both duration and effort of ride.
TurboTurtle 05-13-2008, 04:39 AM Just reading Joe Friel's trainingbible- he mentions a single number to reflect training effort, I know this is poss with a power meter, but for those of us with a HRM how about calories? it will take into account both duration and effort of ride.
An HRM has no way of calculating Calories but the number given may be consistent enough to give you a general 'training effort'.
I think a much better way would be to use one of the Perceived Exertion systems and multiply this number by the time.
TF
EDIT: I just noticed that this is in the Coaching forum. I am not a coach. - TF
android 05-13-2008, 06:55 AM Just reading Joe Friel's trainingbible- he mentions a single number to reflect training effort, I know this is poss with a power meter, but for those of us with a HRM how about calories? it will take into account both duration and effort of ride.
a common way I've seen of doing this is:
x from 1..5
minutes in zone x * x
the total sum is your effort for that ride.
Alex_Simmons/RST 05-13-2008, 07:32 AM Just reading Joe Friel's trainingbible- he mentions a single number to reflect training effort, I know this is poss with a power meter, but for those of us with a HRM how about calories? it will take into account both duration and effort of ride.
HRM calories will only be a ball park estimate and often a bad one at that.
You could consider using TRIMPS as it is based on HR.
Here is an excellent article covering a range of models and references:
http://www.fascatcoaching.com/TSTWKT/
and here is an explanation of the maths used to calculate a TRIMP score:
http://www.ismarttrain.com/articles/TRIMPS.php
iliveonnitro 05-13-2008, 08:11 AM HRM calories will only be a ball park estimate and often a bad one at that.
You could consider using TRIMPS as it is based on HR.
Here is an excellent article covering a range of models and references:
http://www.fascatcoaching.com/TSTWKT/
and here is an explanation of the maths used to calculate a TRIMP score:
http://www.ismarttrain.com/articles/TRIMPS.php
So this is a fairly easy way of doing it. You can do TSS (training stress score) with a HR monitor, which is typically what I advise other people to do.
Do a 30min TT and take the average heart rate for the last 20 min. This is your Lactate threshold (LT) HR. Take your ride and divide your average HR by your LT HR. This will give you a decimal approximation for your "intensity factor (IF)."
The formula is:
TSS = Ride time (in hours) * IF^2 * 100.
Ex) my LT HR is 167. If I go on a 2.5hr ride with avg HR of 143:
IF = 143/167 = 0.86
TSS = 2.5 * .86^2 * 100 = 185
A TSS of 100 = 1hr TT effort. http://www.cyclingpeakssoftware.com/power411/defined.asp for more information.
This also is close to your TSS with power, so you can compare to people who are training with a power meter.
RHRoop 05-13-2008, 01:40 PM Some HRMs actually do this for you- The Suunto T6 for example has metric call EPOC (Excess Post Oxygen Consumption) which is a measure of the training stress based on heart rate variability.
Alex_Simmons/RST 05-13-2008, 01:59 PM So this is a fairly easy way of doing it. You can do TSS (training stress score) with a HR monitor, which is typically what I advise other people to do.
Do a 30min TT and take the average heart rate for the last 20 min. This is your Lactate threshold (LT) HR. Take your ride and divide your average HR by your LT HR. This will give you a decimal approximation for your "intensity factor (IF)."
The formula is:
TSS = Ride time (in hours) * IF^2 * 100.
Ex) my LT HR is 167. If I go on a 2.5hr ride with avg HR of 143:
IF = 143/167 = 0.86
TSS = 2.5 * .86^2 * 100 = 185
A TSS of 100 = 1hr TT effort. http://www.cyclingpeakssoftware.com/power411/defined.asp for more information.
This also is close to your TSS with power, so you can compare to people who are training with a power meter.Unfortunately, while the impulse-response model is quite robust, your proposed method is flawed.
HR alone does not indicate relative intensity very well, even with the squaring of your HRIF (HR does not go to zero and HR has a ceiling, whereas power goes to zero and has no upper bound).
In other words, the weightings of relative intensities will be considerably different to TRIMPS and for TSS. That is why TRIMPS also include a calc to more appropriately weight intensities of sections of the ride, based on what you did, rather than what your HR was.
e.g. in TSS, a borderline steady recovery ride at 55% of FTP yields ~30 TSS/hr, whereas in your proposed model a recovery ride with a HR at 68% of TTHR yields 46 TSS/hr, or over 50% more "TSS" for the same very low intensity ride. That would definitely give one a falsely inflated impression of their ride score.
It would be far better to use TRIMPS as an input into the "impulse - response model", since at least its efficacy has been shown.
You could attempt to play with the slope and intercept values of a HR-based model but there is no getting over the fact HR is poor indicator at higher intensities.
iliveonnitro 05-14-2008, 09:57 PM I'm not sure it would be "far better" to use TRIMPS. In reality, neither of them are accurate.
When you get into short, anaerobic/VO2max intervals, there is a problem with any and all HR-calculating models. Eg, 15-60s intervals will see my HR hit between 89-92% of my max. Considering my FTP HR is 90% of my max, this is no way reflects the intensity that is actually occuring. TRIMPS does look better in a group-ride setting, but still doesn't accurately portray anything other than mostly steady-state efforts.
I do like the TRIMPS idea, though. Unfortunately, all HR-based quantitative models fail, relative to power.
Alex_Simmons/RST 05-16-2008, 01:15 AM I'm not sure it would be "far better" to use TRIMPS. In reality, neither of them are accurate.
When you get into short, anaerobic/VO2max intervals, there is a problem with any and all HR-calculating models. Eg, 15-60s intervals will see my HR hit between 89-92% of my max. Considering my FTP HR is 90% of my max, this is no way reflects the intensity that is actually occuring. TRIMPS does look better in a group-ride setting, but still doesn't accurately portray anything other than mostly steady-state efforts.
I do like the TRIMPS idea, though. Unfortunately, all HR-based quantitative models fail, relative to power.
Since the TRIMPS model weights relative intensity of sections of the ride depending on the zone (and not solely based on HR) - 1 for low level up to 5 for maximal, then it is far better than the proposed HR only model posted.
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