Difficulty reaching target heart rate



Rick, this might help you.



Int J Sports Med. 1992 Aug;13(6):467-70. Related Articles, Links


Day to day variation in time trial cycling performance.

Hickey MS, Costill DL, McConell GK, Widrick JJ, Tanaka H.

Human Performance Laboratory, Ball State University, Muncie, IN 47306.

In an attempt to assess the reproducibility of laboratory cycling performance, eight well-trained (VO2max = 4.6 +/- 0.2 l.min-1) male cyclists completed 12 trials involving 4 successive performance rides at each of three total work outputs (approximately 1600, 200, and 14 kilojoules, respectively). These trials, designated as long, medium, and short trials (LT, MT, ST), represented exercise bouts of 105.12 +/- 0.41, 12.03 +/- 0.17 and 0.55 +/- 0.11 minutes, respectively. The trials, conducted on a computerized cycle ergometer in an isokinetic mode, were separated by a minimum of 72 hrs. All trials for each subject were completed at the same time of day. In all trials, subjects were allowed to select the pace in order to complete the ride in the shortest possible time. The mean coefficient of variation (CV) for performance time in each trial was: LT = +/- 1.01%, MT = +/- 0.95%, and ST = +/- 2.43%, respectively. The CV for performance time in ST was significantly greater than the CV in either LT or MT. In LT, performance time was significantly faster, and the mean % VO2max was significantly higher in trial 4 versus trials 1-3. There was no order effect in the MT or ST rides. The CV for mean VO2 (l.min-1), mean % VO2max, and RER during the LT rides were +/- 3.02%, +/- 3.64%, and +/- 3.53%, respectively. These data suggest that trained cyclists have the ability to reproduce endurance performance with a CV of approximately 1.0% in a time-trial protocol.(ABSTRACT TRUNCATED AT 250 WORDS)

PMID: 1428377 [PubMed - indexed for MEDLINE]
 
These data suggest that trained cyclists have the ability to reproduce endurance performance with a CV of approximately 1.0% in a time-trial protocol.

You suggest that it could be up to 20% variability!. And I say again It is NOT pssible under normal physiological conditions.

You also talk about ---"back to back days of either one-hour TTs or 'hard' RRs (hard being a relative term for the person competing in them)".---- But, you are not talking about Repeatibilty. A TT is way different than a RR. you cannot compare parameters. I don´t quite understand what you meant with the back to back days thing.
 
Originally posted by sanmi, responded with >>

These data suggest that trained cyclists have the ability to reproduce endurance performance with a CV of approximately 1.0% in a time-trial protocol.

>>yes, i haven't disagreed

You suggest that it could be up to 20% variability!. And I say again It is NOT pssible under normal physiological conditions.

>>only 20% variable if my HR max was 100 b/min (which it isn't).

>>performance was the same in the study and with me.


You also talk about ---"back to back days of either one-hour TTs or 'hard' RRs (hard being a relative term for the person competing in them)".---- But, you are not talking about Repeatibilty. A TT is way different than a RR. you cannot compare parameters. I don´t quite understand what you meant with the back to back days thing.

>>i know that a TT is different to a RR!!! i said that at the same mean power HR can could vary by up to 20 b/min on separate occasions.

>>back to back = consecutive days (i.e., i could on a Saturday and sunday do a TT, or a sat TT and a sun RR or a sat RR and a sun RR, etc)

Ric
 
Ric,

Of course that at the same MEAN power it can vary 20 beats per minute!. But you were saying at the SAME power. THere is a huge difference in what you pointed out. You can pedal at a MEAN power of 200watts for 2h. for example in this mean power your power could be from 60 to 325. THe mean HR would be for example 125. But if in a different day you go for 2h at a mean power of 200 but with watts being between 156-225 (differing substantially from 60-325 from the previous test or TT). In this case ,for example, your Hr could be let´s say 149 .Your HR can change even more the 20 beats per minute!. Why?. THe effort is physiologically different between the 2 tests, although both elicit a MEAN power of 200W. but the mean HR differ largely due to different physiological stress.
 
When I say that under normal physiological conditions is not possible a difference of 20 b/m within days, I am Talking about SAME LAboratory or even Field conditions. That is SAME WATTS!! and not SAME MEAN WATT, which can vary largely.
 
About the % variability, you don´t have to have a max hr of 100.
Lets say your doing 355 watts in day one at 172(not max). On day 2 (let´s say 3 days later), your HR at 355Watts is 152 (-20b/m as you pointed out). That is almost a 22% variability.

sanmi
 
Well let me just jump on in there bro's....

I think I am a prime example of someone that has been able to put out the same power on various days, measured by speed and time on a given course with the same wind speed etc with different heart rates. I have done Mt. lemon in tucson at about my lactate threshold which is about 160 bpm and then the very next week do the same ride in the same time with a heart rate of152-but with more preceived effort. Thats a drop in 8 beats per minute with more difficulty reaching that same power output..

But gee Ric....20 beats per minute differences given the same power output and conditions..!? Surely something physiological has to have caused this.

Well I wish I could afford those fancy SMR cranks so I could train knowing my power output but then again heart rate training is pretty darn good too......in fact I think heart rate is a better indicator of bodily effort than power output.
I wonder if training primarily by measuring and focusing in on power output might cause a higher potential for overtraining as heart rate(bodily effort) takes a back seat so to speak. After all it would be human nature to not allow ones power output to ever drop on a given course and type of ride...some days the desired training effect will take place, as measured by bodily effort(heart rate),with a lower power output and some days that same training affect as measures by bodily stimulation(heart rate) will take place at a higher power output.

Perhaps the ultimate type of training would be power out monitoring combined with heart rate monitoring which is indeed what the pro's now do.

BUT!!...If Greg Lemond could reach a VO2 max of 93, 9 better than Armstrong, with only the help of smart training, good genetics and A HEART RATE MONITOR the it is good enough for me.(no SMR cranks for Greg and only limited time on a trainer measuring power output later on in his career)
 
Originally posted by sanmi
Ric,

Of course that at the same MEAN power it can vary 20 beats per minute!. But you were saying at the SAME power. THere is a huge difference in what you pointed out. You can pedal at a MEAN power of 200watts for 2h. for example in this mean power your power could be from 60 to 325. THe mean HR would be for example 125. But if in a different day you go for 2h at a mean power of 200 but with watts being between 156-225 (differing substantially from 60-325 from the previous test or TT). In this case ,for example, your Hr could be let´s say 149 .Your HR can change even more the 20 beats per minute!. Why?. THe effort is physiologically different between the 2 tests, although both elicit a MEAN power of 200W. but the mean HR differ largely due to different physiological stress.

sanmi,

i'll assume that the same power output is the same or almost the same when doing a TT (on a similar/same course) or riding on an indoor trainer*. On a regular basis, i and others that i know can at at the same power (mean and pretty much instantaneous) have HRs that are significantly different (without a change in fitness) of ~ 15 to 20 b/min.

*obviously, it would be impossible for two sessions to be *exactly* the same power

Ric
 
Originally posted by TiMan, i responded with >>

Well I wish I could afford those fancy SMR cranks so I could train knowing my power output but then again heart rate training is pretty darn good too......in fact I think heart rate is a better indicator of bodily effort than power output.

>>the best measure of effort/intensity is effort itself (power output). HR is a dependent variable.


I wonder if training primarily by measuring and focusing in on power output might cause a higher potential for overtraining as heart rate(bodily effort) takes a back seat so to speak. After all it would be human nature to not allow ones power output to ever drop on a given course and type of ride...some days the desired training effect will take place, as measured by bodily effort(heart rate),with a lower power output and some days that same training affect as measures by bodily stimulation(heart rate) will take place at a higher power output.

>>there's probably less likelyhood of overtraining with a power meter than a HR monitor. Firstly, if you can't produce the required power for a days session you might as well go home. secondly, because HR can/does vary at a given workload then some riders will try to force their HR up to a prescribed level (when in fact the target power is at a lower HR).


Perhaps the ultimate type of training would be power out monitoring combined with heart rate monitoring which is indeed what the pro's now do.

>>I've been advocating this for quite a long time! Of course you don't just need to have SRM cranks, there's Power Tap, Ergomo and S710 too!



BUT!!...If Greg Lemond could reach a VO2 max of 93, 9 better than Armstrong, with only the help of smart training, good genetics and A HEART RATE MONITOR the it is good enough for me.(no SMR cranks for Greg and only limited time on a trainer measuring power output later on in his career)

>>apart from the fact that Greg did use an SRM (one of the first pros to do so), even if we assume he didn't use one, would that not be because they weren't invented till later in his career. http://www.srm.de/srmchamps.html

Ric
 
TiMAn,

I totally agree with you. HR is a better and easier parameter to train. If you monitor your physiological parameters overtime(Vo2max and lactate) at a given HR, you will find that they could be very consistant.
But you will find that your Vo2 and lactate could change largely at a given Power output overtime.
Example:
you do a field test or laboratory test.
- TEsta A: heart rate maintained at e.g., 135 b/m for 45 min.
you find that yout Vo2 and Lactate remain pretty constant. THis means that your metabolic stress is constant overtime.
-Test B: SAME (not mean) workload sustained over 45min. LEts say 200 Watts. You will find that a linear increase overtime in VO2 as well as LActate, which means that your metabolic stress is higher overtime. Even a workload of 275Watts sutained over 10minutes elicits different parameters from minute 1 to minute 10.

As you very well pointed out, you have a much higher chances of getting overtrained if you work by watts. It can be very demanding due to the increased metabolic stress as i pointed above.
I have had these discussions with several Top pros before when it became very popular to train by watts. All of them finally realaised that it is not very practical and it was difficult to maintain power output without increasing their effor quite a bit.
THe ideal thing is traininig according to your lactate readings and then "translate" this lactate readings into HR since it is impossible to monitor lactate throught training.

About LeMond´s Vo2Max, It is not possible to have 94 ml/kg/min. It has never been recorded in humans. Probably the metabolic cart they used wass off and overestimated Vo2 max. This happens a lot. It has happened to me a few times when testing athletes. The ventilator meter of the metabolic cart is the one to blame usually. They can go off and overestimate Vo2max.
In this case is not difficult to observe VO2 max in the 90´s in pro cyclists. I used to be a cyclist myself. My Vo2 max was 75.8ml/kg/min (now is 52.....), but I remember once I got to have 92.5 ml/kg/min. The ventilator meter in the metabolic cart was off and it was overestimating the VO2max.


Cheers.
 
Originally posted by sanmi
TiMAn,
bout LeMond´s Vo2Max, It is not possible to have 94 ml/kg/min. It has never been recorded in humans. Probably the metabolic cart they used wass off and overestimated Vo2 max. This happens a lot. It has happened to me a few times when testing athletes. The ventilator meter of the metabolic cart is the one to blame usually. They can go off and overestimate Vo2max.
In this case is not difficult to observe VO2 max in the 90´s in pro cyclists. I used to be a cyclist myself. My Vo2 max was 75.8ml/kg/min (now is 52.....), but I remember once I got to have 92.5 ml/kg/min. The ventilator meter in the metabolic cart was off and it was overestimating the VO2max.


Cheers.

Whilst i have no data on Lemond's Vo2 max, i'm pretty sure there's some good data on a Finnish X country skier with a VO2 max of 93 or 94 mL/kg/min.

As an aside Antelopes (!), can have VO2 max's of ~ 300 mL/kg/min.

Ric
 
your right ric,

Yes there is a data regitered ina finnish x-c skier of 93-94 or so. But I don´t believe that this could be true. I don´t know it´s my opinion...

sanmi.

BTW, you are from south wales?. I though you were from the US, as most people are in cycling forums. THat´s cool. It was great seing MIllar in the worlds!: way to go!.
 
>>the best measure of effort/intensity is effort itself (power output). HR is a dependent variable.

Yes HR is a dependent variable , but don't you think that this fact is indeed the main reason to take HR into serious consideration on any given ride, and base your effort *primarily* on HR . Isn't HR a better indicator of what is happening in ones body, and the resultant training affect, than power output?
We are, after all, trying to produce certain physiological training affects in the body when we ride at various intensities.

I think that power monitoring serves its best purpose by helping(motivating) one to improve power output...to make one a "powerful rider". But then again monitoring speed , time and HR should do the same.

I remember Hinualt "The Badger" saying that focusing on turning big gears FAST made him a powerful rider...perhaps its just that simple>>>develope the mental and physical ability to push a bigger gear faster while monitoring HR.

As a side....he latter on said that he had to learn to use "smaller gears" in the mountains and NOT focus so much on total power output all the time.

As Sanmi mentioned, ideally it would be best to train based on lacate readings as HR can can sometimes vary at various lactate levels(ie: LT threshold doesn't always come at the same HR..BUT it usually does in the fit rider I think)

So maybe in the near future we will see portable lactate monitoring meters on bikes, weighing in at only a couple hundred grams. These monitors might the be able to monitor lactate levels, say ever minute, by taking a drop of blood from a vein. I don't think this is science fiction fella's.

If I had to choose either a heart rate monitor or some type of power monitoring system then I would certainly choose the HR monitor. Damn those pro's though...they get both!

Good thread!

TiMan