Cardiac drift - when and how to measure it?

tonysj

Hi All.
I'm following a 12 week - 5 day a week training plan, not used to this so feeling my way through it, which I'm just starting week 4.
I'm aware of Cardiac Drift during moderate to intense levels of excercise but I'm not sure of how to measure it and which turbo session is best to check it against.
My sessions include some 91% of FTP either 3 x 12 minutes or slight variations on these, 2 × 20, 5 × 10.
I believe your HR will rise over 2 minutes then plateau to the level of exersion during that phase ( 12 minutes at 91% ) so do I measure my BPM of HR at say 2 minutes in to the 12 minutes end of that phase ingoring the first 2 minutes until it plataeus?
Also is the above session long enough to give a good measure of CD as I've read it needs to be over 30 minutes and I'm in for 12mins then backing off to around 45% of FTP for 3 minutes before the next ramped up phase to 91%?
Thanks for any advice.
Regards.
Tony.

imposter2.0

There's no need to 'measure' it and everybody's amount of drift will be different anyway. Use HR as a guide to effort, not a prescriptor.

Jimny14

I'm sure there is a sensible reason you're trying to measure your cardiac drift, please can you explain what you hope gain from measuring it? Thanks.

OnTheRopes

Cardiac drift is a good guide to whether you are sufficiently aerobically trained.
According to Joe Friel you should complete an aerobic threshold ride, so lets say a warm up, 2 hours at Aerobic Threshold and then a warm down.
To calculate the drift it is easier to upload the data into software such as Training Peaks or Golden Cheetah (free) and this will calculate it for you.
What it is basically doing is dividing the threshold part of the workout into 2 , for each half the average power is divided by the average heart rate to establish a ratio then the first half is subtracted from the second half and dividing the remainder by the first half ratio. (which is why its easier to use software designed to do this)
If your power to heart rate shift is less than 5 percent then you are aerobically fit, if greater than 5 percent thn you need more aerobic training.
The ride needs to be steady as jumping around on climbs or harder intervals will throw it out so I would think your example is way too stochastic to measure Cardiac drift

tonysj

Jimny14 wrote:

I'm sure there is a sensible reason you're trying to measure your cardiac drift, please can you explain what you hope gain from measuring it? Thanks.

Being New to training and wanting to increase my FTP for this Summer I've read that when your CD is within 5 to 7% of the lower and higher BPM during moderate-intense exertion then Its showing Im ready to increase my effort levels within that plan, ie; I'm coping well and my fitness to the plan is improving so I should up the effort slightly to build on that fitness.
Bear in mind Ive never had coaching advice as such so its self taught and I could be interpreting what I've read wrongly. :shock:
T.

tonysj

OnTheRopes wrote:

Cardiac drift is a good guide to whether you are sufficiently aerobically trained.
According to Joe Friel you should complete an aerobic threshold ride, so lets say a warm up, 2 hours at Aerobic Threshold and then a warm down.
To calculate the drift it is easier to upload the data into software such as Training Peaks or Golden Cheetah (free) and this will calculate it for you.
What it is basically doing is dividing the threshold part of the workout into 2 , for each half the average power is divided by the average heart rate to establish a ratio then the first half is subtracted from the second half and dividing the remainder by the first half ratio. (which is why its easier to use software designed to do this)
If your power to heart rate shift is less than 5 percent then you are aerobically fit, if greater than 5 percent thn you need more aerobic training.
The ride needs to be steady as jumping around on climbs or harder intervals will throw it out so I would think your example is way too stochastic to measure Cardiac drift

Sounds very technical...Do I have to do that length/type of session, mine is all on a T/training indoors, or could it be gauged in an other way. I'm not wanting to be exact but would use the info as a gauge in some way.
T

OnTheRopes

TonySJ wrote:

OnTheRopes wrote:

Cardiac drift is a good guide to whether you are sufficiently aerobically trained.
According to Joe Friel you should complete an aerobic threshold ride, so lets say a warm up, 2 hours at Aerobic Threshold and then a warm down.
To calculate the drift it is easier to upload the data into software such as Training Peaks or Golden Cheetah (free) and this will calculate it for you.
What it is basically doing is dividing the threshold part of the workout into 2 , for each half the average power is divided by the average heart rate to establish a ratio then the first half is subtracted from the second half and dividing the remainder by the first half ratio. (which is why its easier to use software designed to do this)
If your power to heart rate shift is less than 5 percent then you are aerobically fit, if greater than 5 percent thn you need more aerobic training.
The ride needs to be steady as jumping around on climbs or harder intervals will throw it out so I would think your example is way too stochastic to measure Cardiac drift

Sounds very technical...Do I have to do that length/type of session, mine is all on a T/training indoors, or could it be gauged in an other way. I'm not wanting to be exact but would use the info as a gauge in some way.
T

It depends what you want to measure, if its aerobic endurance then it is to find out if you are aerobically fir enough to start training harder, the endurance would be for the kind of events you intend to do.
According to Friel "In the early base you should start these aerobic threshold rides at 20-30 minutes and then increase them weekly. Do two of these each week during Base. When you can do an aerobic ride for 2 hours while your heart rate and power remain coupled, you can consider your aerobic threshold fitness fully developed."


A bit more info here http://www.sbtriclub.com/decoupling-how-to-determine-if-you-are-aerobically-fit/

Jimny14

My thinking with cardiac drift and using it as a training tool is that its use is limited in my mind. Cardiac drift can vary from day to day due to different parameters including temperature of the room, starting core temperature and hydration. So for pro athletes I can see a place but I'm not sure I would be able to have sufficient control over my relative hydration day to day to make the results all that meaningful. I'd happily be corrected though if I'm wrong.

tonysj

It depends what you want to measure, if its aerobic endurance then it is to find out if you are aerobically fir enough to start training harder, the endurance would be for the kind of events you intend to do.
According to Friel "In the early base you should start these aerobic threshold rides at 20-30 minutes and then increase them weekly. Do two of these each week during Base. When you can do an aerobic ride for 2 hours while your heart rate and power remain coupled, you can consider your aerobic threshold fitness fully developed."


A bit more info here http://www.sbtriclub.com/decoupling-how-to-determine-if-you-are-aerobically-fit/[/quote]
Thanks for this OTR but an I right in thinking I should ride the turbo Zone 2 at 55% - 75% of FTP ( 55-75% FTP power / 68-83% threshold HR / 60-70% MHR ) for 2 hours and use the equation from your link to check CD?
Tony.

maryka

https://www.trainingpeaks.com/blog/how- ... ecoupling/ is a better explanation.

cougie

You'll have to exercise for such a long time see CD that I don't think it's beneficial as part of a training plan. It would take a while to get over the session.

I definitely saw it on marathons but that's three hours worth of hard exercise.

tonysj

cougie wrote:

You'll have to exercise for such a long time see CD that I don't think it's beneficial as part of a training plan. It would take a while to get over the session.

I definitely saw it on marathons but that's three hours worth of hard exercise.

Thanks for all the advice folks. I think I will just follow the plan and go by Perceived Effort/feel to decide if I need to increase the load on sessions.
Regards.
Tony.r

Typical Analytical

My favorite subject!

First of all, the consistency, precision and repeatability of ERG training indoors is the ideal way to harness the power of cardiac drift. There are too many reasons for this to mention here so I'll just mention two:

If you want to understand and consistently measure the relationship between effort and power then fixed power is the way to do that. My favorite analogy is if you go to the gym and you want to know how many times you can lift 200 lbs then you are going to find 200 lbs and lift it. You aren't going to lift 50 lbs and then 400 lbs and then 75 lbs and then try to normalized it.

On the effort side of things, under controlled conditions, the effort to produce power, the measure of effort (HR) to produce power, and things that effect the measure of effort to produce power (hydration) are all unaffected by changes in conditions and therefore changes in performance from one workout to the next can be more confidently attributed to actual changes in training status (i.e. the state of fitness, fatigue and endurance).

I could go on but let's turn our attention to how to use this information:

Endurance - Cardiac drift is a measure of endurance. A lower/decreasing drift is an indication of improved endurance.

Duration - Cardiac drift can help ensure proper stimulus for endurance development. The rule of thumb is to aim for a duration that elicits between five and ten percent cardiac drift. If you are under 5% then increase duration of next workout. If over 10% then decrease duration of next workout.

Readiness - When you are able to manage a cardiac drift of 5-7% for the duration of your target event then (1) endurance is adequately developed, (2) your body is ready for higher intensity work and (3) you can move into maintenance mode for endurance which for many athletes is one endurance ride per week

Fatigue - A decrease in average heart rate than coincides with an increase in cardiac drift is likely due to a suppressed (lower than average) heart rate from fatigue. As fatigue accumulates, so will cardiac drift. This is because HR suppression from fatigue often disproportionately impacts the first half of the workout (because HR can return to a normal level later in the workout after being suppressed initially) and, since cardiac drift is measured by comparing first half of workout vs second half of workout heart rate, cardiac drift will skew upward with additional fatigue. You can see this phenomenon in the purple bars at the bottom of this chart.



Applicable to workouts of all intensities - Apples to apples, a decrease in cardiac drift is preferable. I monitor it for all of my workouts. If cardiac drift is lower for the same workout, then that is good. If it is higher then that is likely not good. I always control or am at least aware of and take into consideration possible impacts of hydration, nutrition, stress, sleep quality, etc. so it's not a be-all end-all.

Power vs time - I'm looking for a cardiac drift of 5-10% for all of my workouts. Among other things, this allows me to do things like assess the effectiveness of intensity-for-time substitutions. For example, if I don't have time to perform a 1x120 session at aerobic threshold then I may perform a shorter Tempo ride in its place and I know I got the intensity/duration combo right if cardiac drift lands between 5-10%.

OnTheRopes

Typical Analytical wrote:

My favorite subject!

Yes we know
I'm just surprised it took you so long to get here. The OP has long since decided it's not for him and moved on.
Still, good post nevertheless.

tonysj

Typical Analytical wrote:

My favorite subject!

First of all, the consistency, precision and repeatability of ERG training indoors is the ideal way to harness the power of cardiac drift. There are too many reasons for this to mention here so I'll just mention two:

If you want to understand and consistently measure the relationship between effort and power then fixed power is the way to do that. My favorite analogy is if you go to the gym and you want to know how many times you can lift 200 lbs then you are going to find 200 lbs and lift it. You aren't going to lift 50 lbs and then 400 lbs and then 75 lbs and then try to normalized it.

On the effort side of things, under controlled conditions, the effort to produce power, the measure of effort (HR) to produce power, and things that effect the measure of effort to produce power (hydration) are all unaffected by changes in conditions and therefore changes in performance from one workout to the next can be more confidently attributed to actual changes in training status (i.e. the state of fitness, fatigue and endurance).

I could go on but let's turn our attention to how to use this information:

Endurance - Cardiac drift is a measure of endurance. A lower/decreasing drift is an indication of improved endurance.

Duration - Cardiac drift can help ensure proper stimulus for endurance development. The rule of thumb is to aim for a duration that elicits between five and ten percent cardiac drift. If you are under 5% then increase duration of next workout. If over 10% then decrease duration of next workout.

Readiness - When you are able to manage a cardiac drift of 5-7% for the duration of your target event then (1) endurance is adequately developed, (2) your body is ready for higher intensity work and (3) you can move into maintenance mode for endurance which for many athletes is one endurance ride per week

Fatigue - A decrease in average heart rate than coincides with an increase in cardiac drift is likely due to a suppressed (lower than average) heart rate from fatigue. As fatigue accumulates, so will cardiac drift. This is because HR suppression from fatigue often disproportionately impacts the first half of the workout (because HR can return to a normal level later in the workout after being suppressed initially) and, since cardiac drift is measured by comparing first half of workout vs second half of workout heart rate, cardiac drift will skew upward with additional fatigue. You can see this phenomenon in the purple bars at the bottom of this chart.



Applicable to workouts of all intensities - Apples to apples, a decrease in cardiac drift is preferable. I monitor it for all of my workouts. If cardiac drift is lower for the same workout, then that is good. If it is higher then that is likely not good. I always control or am at least aware of and take into consideration possible impacts of hydration, nutrition, stress, sleep quality, etc. so it's not a be-all end-all.

Power vs time - I'm looking for a cardiac drift of 5-10% for all of my workouts. Among other things, this allows me to do things like assess the effectiveness of intensity-for-time substitutions. For example, if I don't have time to perform a 1x120 session at aerobic threshold then I may perform a shorter Tempo ride in its place and I know I got the intensity/duration combo right if cardiac drift lands between 5-10%.

Thanks for that TA.
I'm checking my HR to compare same intensity sessions and I've seen a drop in the lower and higher and average for the segments so I must be doing something right with my fitness improving.
Tony.