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2008-10-26 7:57 AM

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Subject: newbie question: how to fight cardiac drift?

I am a 53 y/o male, trying to establish a very strong running base over the next months. I do have some Tri experience, but that goes back about 12 years. For right now I am concentrating on building my base, and want to concentrate on building time.

Question: During my run my HR is going slowly but steadily up until (and maybe slightly above)  Zone 2 (70-80% of max). While trying to increase my running time my HR may exceed Zone 2 gradually. Do I stop running and start walking in order to get HR back into the Zone and sacrifice my "new time goal", or do I keep running but HR is beyond the upper limit of Zone 2? I presume that this is called "cardiac drift"? Should I sacrifice my time goal, or should I continue to run albeit slightly outside my window?

Thanks for your input, I tremendously enjoy the lessons and advice learned on this web site.

Ralph

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2008-10-26 8:46 AM
in reply to: #1766322

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Subject: RE: newbie question: how to fight cardiac drift?

Welcome to BT!

Just how long are we talking about here for your long runs in time?  Because it is pretty much impossible to "fight" cardiac drift.  It happens to everyone, even the elites.  It is just part of the human physiology.  If it is happening over a 30 minute run, then it is just a fitness thing, it will come back with time.  If it is over say a 90 - 120 minute run, that is normal.

Of course your ability to maintain a consistent pace with minimal increases in HR over the time of effort will come with more training, but you will still have some cardiac drift.



Edited by Daremo 2008-10-26 8:47 AM
2008-10-26 10:31 AM
in reply to: #1766322

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Subject: RE: newbie question: how to fight cardiac drift?

Cardiac drift cannot be avoided completely, as was said above.  Many people seem to think it is due to dehydration.  (Theory:  blood volume decreases, so heart must work harder.)  It's not a bad theory, but it is apparently wrong.

Current wisdom among those who like to train by HR is, I think, to respect the HR even after drift has occurred.  I.e., slow down to maintain the desired HR.

Some will disagree, especially those who prefer training by other measures.  (Studies suggest that VO2 max decreases as cardiac drift occurs, so those who like to train by VO2 max would probably also want to take cardiac drift as a sign to slow down a bit.)

Anyway, here's an article that might be helpful (it mentions some of those studies):

    http://www.petersenperformancelab.net/quarterly%20article.htm
 

 

2008-10-26 10:33 AM
in reply to: #1766322

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Subject: RE: newbie question: how to fight cardiac drift?
Im not sure where you are located, but if it is somewhere warm dehydration can definitely lead to cardiac drift. Cardiac output is the amount of blood that the heart pumps and it is based off stroke volume (how much blood the heart moves in one beat) and heart rate. As you dehydrate your blood volume decreases and so does your stroke volume so your body increases HR in order to keep cardiac output at the level needed for the intensity of the exercise. The way to fight this type of cardiac drift is simply to hydrate as much as possible while exercising. I would not worry much if your HR is a little out of each "zone." Your body does not have any exact zones, it is a mix of multiple systems working together so even though you may technically out of your zone your body will still benefit in much of the same way. Hope this helps!
2008-10-26 10:47 AM
in reply to: #1766322

Subject: RE: newbie question: how to fight cardiac drift?

Hello

I am also working on base building.  I have found a few things over the past month.  My rate is increased and dips into Z3, but it is ony by a few beats.  The HRm I use differs in the Z2/3 range from the BT zone calculator on this site by several beats.  I also found that it always goes up when I take a drink, play air gutiar or drums as I am running down the road and what song I am signing.  Since I run by myself, I tend to sign to use the easy conversation rule of thumb.

I was slowing down to stay in the Z2, but now when I drift up into Z3 I look at how high I am in the zone, like one or two beats.  If I am signing ok  (carryng a tune not required) and am not grasping for breath then it's all good.  I just keep going and maybe stop playing those air drums.  I usally drop right back inot Z2.

I seem to drift up to the mid 130, low 140 range and stay there for the duration of my runs.  However the drops when I stop are coming much quicker everytime.  This drop to a lower HR tells me I am getting in better shape. 

Joe

2008-10-26 11:37 AM
in reply to: #1766322

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Subject: RE: newbie question: how to fight cardiac drift?
Cardiac drift will occur regardless of heat, hydration and level of fitness. Joe Friel and others have written about it extensively. Also known as "decoupling" in literature, when compared to pace.
It is more apparent and pronounced with athletes working on aerobic fitness in the early base period when establishing basic endurance ability. With increase in base fitness, cardiac drift will reduce, but will never be enitrely eliminated.
Best way to deal with this in early base is to find a pace that will start you in low to mid Z1 and keep it for duration of the run. You will notice that the cardiac drift will probably have you finish the run in mid to upper Z2, depending on your fitness level. But key is chosing a pace that will feel very easy to start and verify with HR monitor that you are in Z1. Later as you increase your fitness level, that same pace will not take you into Z2 maybe at all. That is how I would do it.
Now, folks that use HR as a primary intensity measurement will walk it to keep it down, within the assigned zone. That most likely leads into a gradual slowdown throughout the run.
Heat and dehydration have their effect on cardiac drift. During initial heat acclimation process you will once again experience that same large drift as you did in early base, even though your fitness levels could be high. Again, hydrating adequately and exposing your body to workout in heat and humidity will lead to acclimation and the cardiac drift will reduce once again to more moderate levels, which will signal your heat acclimation process relatively complete.
Joe Friel explains this in detail and uses the measurement of cardiac drift as one of the parametars of aerobic fitness relative to decoupling. I suggest you look at a few of his books and search his blog as he covers it there.


2008-10-26 11:46 AM
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Subject: RE: newbie question: how to fight cardiac drift?

mutri - 2008-10-26 11:33 AM Im not sure where you are located, but if it is somewhere warm dehydration can definitely lead to cardiac drift. Cardiac output is the amount of blood that the heart pumps and it is based off stroke volume (how much blood the heart moves in one beat) and heart rate. As you dehydrate your blood volume decreases and so does your stroke volume so your body increases HR in order to keep cardiac output at the level needed for the intensity of the exercise. The way to fight this type of cardiac drift is simply to hydrate as much as possible while exercising. I would not worry much if your HR is a little out of each "zone." Your body does not have any exact zones, it is a mix of multiple systems working together so even though you may technically out of your zone your body will still benefit in much of the same way. Hope this helps!

Studies like this one (Med & Sci in Sports and Exercise 38(5): 901) indicate pretty clearly that hydration will at most delay the onset of cardiac drift.

Arguments like this one (Science of Sport blog, October 2007) convince me that 'hydrate as much as possible while exercising' is not a good idea. Not to mention that it can kill you .

 (Edit: added link.)



Edited by mdickson68 2008-10-26 11:48 AM
2008-10-27 1:34 AM
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Subject: RE: newbie question: how to fight cardiac drift?

Two changes I would experiment with: #1 -- start easier, don't force your HR up earlier in the workout.  #2 -- use run:walk protocol.

 http://www.coachgordo.com/gtips/publish/2006/12/bobby-mcgee-runwalk-protocol.html

 Using run:walk, I am willing to bet that you will immediately go further on you long runs with a lower average HR.  Key thing to remember is that you walk with a purpose and start with 5-10 mins of walking.  

Feel free to follow-up after you try.  This isn't just for AG runners -- I've run 1:15 half marathons (off the bike) using this technique.

g

2008-10-27 2:47 PM
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Subject: RE: newbie question: how to fight cardiac drift?

As mdickson68 can’t be avoided. There are certain things that might help delay it but the reality is that HR can be affected by many external things not directly related to the type of intensity/effort at which you are training at. HR is response NOT a dose for the given work done.

IMO it is better to guide your training intensity by pace/RPE and worry too much as to how your HR is responding to that effort. In many instances your HR will indicate higher readings due to the weather, lack of sleep, diet, stress, etc. and it changes day after day.

I strongly disagree with the notion that base training should be limited to a particular effort/intensity and even slow down/walk just to keep your HR down. Considering the many variables that affect HR you might very well end up under/over training by following your HR exclusively and in the end it will defeating the goal (adaptations) for that given session. In addition what constitutes a stronger endurance base is the ability to hold a higher power output and have the endurance to sustain that over time (work over time).

AGers with limited time in particular should try to maximize training adaptations given their time availability. Doing higher volume at lower intensities to achieve greater training loads will not be a realistic goal to shoot for most. For that reason seeking to increase your training load with a lower volume and higher intensity will result in a better return on investment. As you move through your plan into race specific training then you can focus on the key session that will allow you to go the distance as fast as possible. Training slow will cause your race slow.

2008-10-27 2:59 PM
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Subject: RE: newbie question: how to fight cardiac drift?
GordoByrn - 2008-10-26 11:34 PM

Two changes I would experiment with: #1 -- start easier, don't force your HR up earlier in the workout.  #2 -- use run:walk protocol.

 http://www.coachgordo.com/gtips/publish/2006/12/bobby-mcgee-runwalk-protocol.html

 Using run:walk, I am willing to bet that you will immediately go further on you long runs with a lower average HR.  Key thing to remember is that you walk with a purpose and start with 5-10 mins of walking.  

Feel free to follow-up after you try.  This isn't just for AG runners -- I've run 1:15 half marathons (off the bike) using this technique.

g

 

5-10 minutes of walking and you still crush me by 45 min on a stand alone half!



Edited by sax 2008-10-27 3:00 PM
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