Post Number: 1418
|Posted on Thursday, April 02, 2009 - 06:10 pm: |
Here an interesting article I got sent from a friend to share .
As you will see in the barticle there are some open questions on cardiac remodelling in horses, maximal heart rate as a not as good indication on fitness and our most interesting question.
If the SV in a horse can increase, as it can in humans , than we have a similar open question we work on the human training for the moment. The question is the CCT or Cardiac contraction time.
Andrew sent me today another nice way of looking at the problem.
The actual cardiac filling time.
Here short what we discuss.
The heart get's its O2 blood during diastolic action. It has minimal O2 delivery during systolic action. Now in humans the filling time shortens , and on the other side the contraction time get's longer.
We see a potential trend in the way that short after an athlete reaches his 30 sec contraction time we have lactate in the blood and we see the LBP coming up.
The reason is a too long LVET . So CCT is HR x LVET.
If the SV increases and not just as a better EF % , but as a real increase due to a bigger EDV we have a structural remodelling in the hu7man heaet , which can go together with changes in LVET . The HR seems to be more of a functional reaction, the LVET seems to be both. So as LVET goes up so can CCT go up and the LBP seems to drop but together with the drop we may see a better performance due to a bigger CO.
If this is the case in humans it could be as well in horses, which would mean the maximal HR over time would drop but performance would increase.
Or the question is , whether horses with lower maximal HR may have already a bigger heart . This would therefor ask for a review on Leonies claim , that Horses with lower Max HR have no potential of ebing good and successfull race horses. Here the article to enjoy .
Return to AERC Home Page
AERC VET FORUM
The heart: how it works & what can go wrong
By Todd C. Holbrook, DVM
The horse's heart and blood vessel (cardiovascular) system is one of the key components required for optimal athletic performance. The modern-day horse has evolved over thousands of years with selective pressures aimed at improving athletic performance. This has resulted in an animal with a large heart which has high blood pumping capacity. In this article I will review some of the basic functions of the heart, the cardiovascular response to training and exercise, as well as review some causes of poor performance related to heart function.
The heart as a pump -- why is this important?
The horse's heart, like ours, has four chambers with associated valves that open and close as the heart muscle relaxes and contracts to insure blood flows in the right direction. Specialized cells within the heart conduct electrical activity that coordinates the muscles of the heart to contract in an appropriate manner to optimize blood pumping. The right and left atria are smaller volume chambers at the top of the heart that receive blood returned from either the lungs (left atrium) or the body (right atrium).
When the atria contract, each delivers blood to the larger volume ventricle that lies beneath. The right side of the heart receives unoxygenated blood from the body and pumps it to the lungs to allow the red blood cells to uptake oxygen. Oxygenated blood returns to the left side of the heart, and the left ventricle pumps it out the aorta to the rest of the body.
Simply stated, the larger the heart is, the more volume of blood it can pump. Thus, heart size is a major determining factor of stroke volume (SV) or the volume of blood pumped per heart beat. Stroke volume in a horse at rest is around 1000 ml, and increases to around 1700 ml at maximal exercise. The cardiac output (CO), or volume of blood pumped per minute, is equal to the heart rate (HR) multiplied by the stroke volume.
With exercise onset, the horse's heart rate increases from a resting rate of 30 to 40 beats per minute to around 110 beats per minute. Stroke volume increases also, due to increased volumes of blood returned to the heart. The heart muscle responds to this increased volume and pressure with stronger contractions.
Thus with the initial demands of exercise, cardiac output rapidly increases. This increase is required to supply working muscles with oxygenated blood. The maximal oxygen uptake or VO2 max is also known as aerobic capacity. Among animals of comparable size, the horse is superior in its ability to consume oxygen (>200mlO2/min/kg).
It is generally accepted that the ability of the horse's muscle mass to consume oxygen far exceeds the ability of the heart and lungs to provide oxygenated blood. Thus conditions that result in improved cardiac output positively impact performance, whereas conditions resulting in reduced cardiac output can directly negatively impact performance.
Do athletes with bigger hearts perform better?
As explained above, the larger the heart, the higher the cardiac output. The impact of heart size on performance is supported by relative heart sizes in famous human and equine athletes. One multiple Olympic champion distance runner had a heart mass that was almost three times larger than predicted for his body size. Triple Crown winner Secretariat's heart was estimated to be 22 poundsŃnearly 10 pounds heavier than the heart of an unexceptional stallion. The impact of cardiac size on endurance performance in the horse is currently unknown; however, a number of famous endurance horses anecdotally had large hearts.
In racing Thoroughbreds, maximal oxygen consumption is an excellent determinant of performance, and heart size is related to both VO2 max and racing performance. Whereas elite Thoroughbred racehorses perform near VO2 max at top speeds, endurance horses typically compete at 30% to 55% VO2 max.
What's different about the cardiovascular requirements of endurance exercise?
Exercising muscles produce excessive heat during work that must be balanced with efficient body cooling. Increases in cardiac output are required not only for working muscle, but also to supply blood flow to the skin to allow for optimal sweating and heat dissipation.
In the endurance horse, the thermoregulatory system is of utmost importance. Comparatively, much more cardiac output is required for thermoregulation with endurance work than with short distance racing. During endurance exercise, fluid loss from sweating can reduce circulating blood volume. The resulting competition for cardiac output between working muscles and skin can become critical. Because the central cardiovascular needs take precedence, skin blood flow is reduced to maintain circulating blood volume and heat stress often results.
The maximal heart rate in the horse varies from just over 200 to around 240 beats per minute. During racing, Thoroughbreds typically achieve heart rates that are close to maximum, while endurance racing horses typically maintain a lower working heart rate for long periods (120 to 160 beats per minute). However, with sprints at race finishes, elite endurance horses also likely achieve heart rates approaching maximum.
How does the cardiovascular system respond to training?
As horses become more fit with training, a number of adaptations occur in the cardiovascular system. In both humans and dogs, endurance training causes a reduction in resting heart rate. Although I am not aware of a study that addresses this question in endurance horses, my impression is that resting heart rate also decreases with training in endurance horses. Most literature of cardiovascular exercise physiology addresses the Thoroughbred race horse, wherein there is not a reduction in resting heart rate with fitness.
Heart rate during submaximal exercise does decrease with training. In other words, the heart rate required to trot or canter at a set speed from point A to point B will be reduced as the horse becomes more fit. The heart rate monitor is a valuable tool when utilized to assess fitness in this manner.
Although there is a linear relationship between running speed and heart rate, maximal heart rate is not a good measure of athletic fitness. Furthermore, maximal heart rate is not increased with training. Speed or velocity at a specific submaximal heart rate is related to stroke volume, fitness and performance.
The reduced heart rate during submaximal exercise is due to a number of factors that are altered with training. Blood volume increases in horses due to training by about 10%. This increased blood volume is due to both increased plasma volume and red blood cell volume. These changes optimize oxygen-carrying capacity, and provide greater plasma volume for improved thermoregulation. The increased blood volume is one factor that leads to increased cardiac stroke volume secondary to training. Mathematically, because CO = HR x SV, the increased stroke volume induced by training provides the maintenance of cardiac output for submaximal exercise, while allowing a reduction of heart rate.
The heart itself remodels in humans and dogs as a result of endurance training. Recent studies in racehorses indicate remodeling also occurs in the horse in response to training. Heart mass and the left ventricular internal diameter increases with training. The size of the left ventricle has also recently been correlated with performance in both Standardbred and Thoroughbred racehorses. The impact of endurance training on cardiac remodeling in the horse, and the importance of heart size on endurance performance, have not been studied.
How is heart rate recovery affected by training and exercise?
AWith improvement in fitness, the heart rate recovery time post-exercise is shortened. In other words, the horse's heart rate drops more rapidly toward normal after exercise as fitness improves. Checking the heart rate monitor at intervals after completing a defined distance is a valuable method to assess fitness during training. During competition the rider and veterinarian often utilize this information on the ride card to monitor the horse's condition. With dehydration, metabolic dysfunction, fatigue and even lameness, heart rate recovery is adversely affected. This is the basis of the cardiac recovery index (CRI).
How can heart problems cause poor performance?
AAdequate cardiac output must be maintained to sustain muscular work; therefore, any condition that results in reduced cardiac output below that necessary for a given workload can reduce performance. In the horse, reduced cardiac output can result from arrhythmias (abnormal heart rhythm) that cause uncoordinated contraction of the heart.
Heart murmurs can also be associated with poor performance. If one or more of the heart valves does not close properly, this can disrupt normal blood flow in the heart and cause a heart murmur. Depending on the location, severity, and duration of the valve leakage, changes in cardiac function can result which may negatively impact athletic performance.
The most common arrhythmia that causes poor performance in horses is atrial fibrillation. During this condition, the electrical activity of the top chambers of the heart (atria) is uncoordinated. This results in reduced pumping of blood to the ventricles, as well as an irregular ventricular rhythm. The resulting reduced cardiac output can cause poor performance.
I have diagnosed paroxysmal atrial fibrillation that has developed during competition in a number of endurance horses. In this situation it may be related to electrolyte disturbances. Indeed in one recent case it was associated with inappropriate calcium supplementation during competition. Horses that develop atrial fibrillation during competition should receive veterinary attention. Evaluation will usually include assessment of the horse's serum electrolyte status and electrocardiogram recording. The condition may resolve over time with correction of the electrolyte abnormality. Because there can be other causes of atrial fibrillation, and this arrhythmia can indicate underlying heart disease, a thorough cardiac workup is recommended.
Other exercise-induced arrhythmias may also result in poor performance. The diagnosis of these problems often requires evaluation of the horse's heart rhythm during exercise on a treadmill.
Heart murmurs are quite common in horses, especially athletes. Rapid blood flow out the major vessels at the heart base during contraction of the heart commonly results in innocent flow murmurs that are not caused by valve leakage. These are normal murmurs caused by turbulent blood flow, and do not impact on the horse's performance. It can be difficult to determine the seriousness of a murmur by the stethoscope alone, and sometimes even suspected innocent flow murmurs should be confirmed with a more in-depth cardiac workup. Because specialty equipment and advanced veterinary training is often required for extensive cardiac workup, this often necessitates transport of the horse to a university teaching hospital or referral clinic.
Murmurs associated with the valves between the atria and the ventricles can result in poor performance, especially on the left side of the heart (mitral valve). Mitral valve insufficiency can result in heart enlargement, atrial fibrillation, and ventricular arrhythmias. A thorough cardiac examination including ultrasound of the heart (echocardiography) is warranted in any horse that has a significant heart murmur.
One of the more common murmurs I recognize in older endurance horses is called aortic insufficiency. In this disease, there is a progressive degeneration of the aortic valve, and as the valve function worsens it results in reduced performance. After the left ventricle contracts to pump oxygenated blood out the aorta, the insufficient valve allows blood to flow backwards into the left ventricle during the resting phase of the heart cycle. This results in a reduced effective cardiac output. This murmur is more common in horses over 15 years of age. I have heard a number of rather loud aortic insufficiency murmurs in older endurance horses that have competed for years with the condition at lower levels. Because it is a progressive disease, horses with aortic insufficiency should be monitored over time with echocardiography.
In this article I have briefly reviewed some basic concepts of how the horse's heart functions during exercise and how a few conditions can affect performance. If you have any questions regarding this topic or any other medical condition in your horse, please feel free to drop me an e-mail or pick up the phone.
Todd C. Holbrook, DVM, Diplomate ACVIM, Assistant Professor of Equine Medicine at Oklahoma State University in Stillwater, Oklahoma, is a member of AERC's Veterinary Committee. He may be reached at email@example.com or 405-744-6656.
Post Number: 24
|Posted on Thursday, April 02, 2009 - 11:51 pm: |
The question of a lower maximum heart rate denoting that the horse has a larger heart and therefore does not need to have a higher rate was my premis years ago also. Disproved that theory after many years of believing it, sadly to say.
Post Number: 14
|Posted on Friday, April 03, 2009 - 10:16 am: |
These horses that had low maximum heart rate, what were their resting HR and exercising HR compared to horses with normal maximum HR?
Post Number: 1420
|Posted on Friday, April 03, 2009 - 10:30 am: |
Hallo Leonnie ,
great and short and clear response. Thanks.
If we have this clear answers as you present here, it would be nice to see the data , as you seem to have tested this in many many cases. Can you for the interested reader publish the data here on the EDV and SV changes , resp. no changes and the comparison of cardiac output with the horses on a high heart rate you tested to the cardiac out put with the horses on the lower heart rate you tested.
This would be very interesting , as well just one example of a step test you do on the treadmill with your horses, where we see the heamodynamic behaviour of the horses heart as they go faster and on a higher intensity.
This way we can see the different parameter, who influence cardiac out put and ultimately the VO2 situation ,. which is a part of the overall performance.
This data you have will end for sure the discussion, that in horses a higher heart rate is the ultimate marker for performance, which at least on that area would show a clear difference to human athletes, where this notion is more likely not true.
Thanks in advance for the data you show us , as many readers have a lot of interest in this clear research so that believe is replaced by scientific information.
Last nut not least , what equipment do you use on the horses on the treadmill, when you test cardiac output , as well as EDV. SV , EF % and LVET . Can you give me the companies name, as it would be interesting to compare the technology they use with the human used equipment.
Thanks for the info, and the clear answer and the back up of your answer with the data collection. Cheers Juerg
Post Number: 1421
|Posted on Friday, April 03, 2009 - 04:54 pm: |
Here from horse people for horse people, but still interesting for human coaches.
Maximum Heart Rate (Max HR)
Before answering the question ‘How do I determine the maximum heart rate of a horse?’
It is important that you are aware of some of the following facts about a horse’s
maximum heart rate:
1. Maximum heart rate is genetically determined so there will obviously be the
possibility of big differences between individual horses. For example, maximum
heart rates of 190 to 255 beats per minute have been reported in the equine
scientific literature. However, it would seem that a ‘ball park’ figure of 230 beats
per minute is a reasonable approximation for the maximum heart rate declines with
age according to the formula: Max HR =220 – age. However, there seems to be no
predictable relationship between age and maximum heart rate in horses.
2. Maximum heart rates that are high do not predict better racing performance, just as
maximum heart rated that are low do not predict worse racing performance.
3. Maximum heart rate does not increase with training or fitness.
4. Maximum heart rate can be affected by the type of exercise the horse is performing.
For example, the maximum heart rate for a horse swimming may be significantly
different to that for galloping. This, of course, has implications when it comes to
setting heart rate training zones for swimming and running.
You should not assume that maximum heart rates will be the same for
all types of exercise.
5. Drugs can affect maximum heart rate.
6. Maximum heart rate can be reduced as a result of over training and fatigue.
7. It seems horses can achieve their maximum heart rate in a very short period of time.
One study which examined thoroughbreds (Krzywanek et al, 1970) reported a rise
in heart rate from 121 to 221 beats per minute within 7.5 seconds! However, on
average, it took 22 seconds for the heart rate to rise from the pre-start level to the
peak heart rate level. However, in standardbreds trotting at speeds of 12.0 to 12.5
meters per second, maximum heart rates were not reached until after 700 meters or
56 to 58 seconds.
Determining the maximum heart rate of your horse…
As is the case with human athletes, maximum heart rate can either be predicted or
measured. Both techniques have advantages and disadvantages.
For humans, the formula of 220 – age is often used to predict the maximum heart rate
of an individual. While this formula is reasonably accurate, there doesn’t seem to be
a predictable link between horse’s age and its maximum heart rate. As a starting
point, it would seem that the figure of 230 beats per minute would be a reasonable
‘guesstimate’ for your horse’s maximum heart rate.
Keep in mind that while the prediction method requires no effort and gives you a
starting point for setting heart rate training zones, it is not specific to swimming and
may be an over or under estimation of what the true maximum heart rate of your
horse really is.
The best way to actually identify the true maximum heart rate of your horse is to
measure it during a strenuous exercise session. The following are some suggested
? An all-out trial over 1000 – 1600 meters
? A continuous progressive test
? A hill test
An all-out trial over 1000 – 1600 metres:
It is not uncommon for horses to be barrier trialed under competition conditions
during their preparation-training phase. This is an excellent opportunity to measure
maximum heart rate (assuming the horse goes ‘all-out’ during the trial).
Figure 1: gives an example of a horse’s heart rate response during a 1000 meter trial.
The heart rate at the end of the race can be assumed to be a good indication of the
horse’s maximum heart rate. In general, maximum heart rate in a horse can be
measured after one minute of maximum effort, provided the horse has undertaken a
suitable warm- up.
Figure 1: Horse’s heart rate response
during 1000 m trial
A continues progressive test
This test requires progressive increases in galloping speed, in steps, over a period of
2-3 minutes until maximum effort is achieved. An example of this type of test is
given below. Remember that the galloping speeds you use will vary depending on
the fitness and ability of the horse. The test itself could quite easily take the place of
the training session.
Table 1: Results of a continuous progressive test
Step Galloping Speed Heart Rate Time to Cover
1 11 m/sec or 39.6 kph 174 bpm 36 sec 36 sec
2 12 m/sec or 43.2 kph 191 bpm 33 sec 69 sec
3 13 m/sec or 46.8 kph 207 bpm 31 sec 100 sec
4 14 m/sec or 50.4 kph 224 bpm 29 sec 129 sec
5 15 m/sec or 54.0 kph 230 bpm 27 sec 156 sec
6 All-out 231 bpm N/A
The above test would take approximately 2.5 -3 minutes to complete with only the
last three steps being really strenuous. Step 6 requires an all-out effort – maybe
which lasts only for 5-10 seconds. The maximum heart rate ought to occur at the end
of the test.
A hill test
Many trainers prefer to use a long steep hill to identify their horse’s maximum heart
rates. However, before attempting the test, it is suggested the horse has traveled the
hill many times in training at gradually increasing speeds over several weeks.
It is suggested to roll into the hill and gradually increase running speed until you get
to the top or until the horse starts to tire (hopefully both occur at the same time).
Check the heart rate at the end of the climb.
Irrespective of which method you decide to use, you should include the
? Where possible, try and standardize conditions such as the time of day
(morning, afternoon, or evening) and weather conditions (cool, warm or hot).
Record these each time you conduct the test.
? Plan the time of your horse’s feed before it takes the test. Wait at least 2-3
hours after a medium to large feed, before you conduct the test.
? A true maximum heart rate can only be established when the horse is fully
rested. At least one recovery or easy training day before the test is necessary,
if the horse has exercised or trained hard 1-2 days beforehand, you have very
little chance of reaching its true maximum heart rate.
? Warm-up and Cool-down the horse thoroughly!
? If you and/or the horse are inexperienced in conducting the maximum heart
rate test, you may wish to repeat it a few days later in order to verify the
? With some Polar watches (receivers) you can record the heart rate in the
memory and retrieve the information at the end of the test. This function
certainly makes it easier for the rider who can concentrate on ‘horse control’
and riding speed.
" 2. Maximum heart rates that are high do not predict better racing performance, just as
maximum heart rated that are low do not predict worse racing performance."
The second thought from the human side is:
Max HR is "genetically " fixed.
The critical question is here rather :
CO may be genetically given as in EDV. So as there is no research out ) Besides Leonnie CO testing ) we may have to consider the possibility , that due to the lack of long term testing on cardiac heamodynamic we still are in the field of "believe" and experience , than in the field of knowing. So we will keep searching for more info in this very interesting direction.
As you can see the different ideas on Max. HR in horses, we have a similar problem in human coaching , as many many still believe that 220 - age is something who works.
So lot's of the same in both fields .
Post Number: 1422
|Posted on Saturday, April 04, 2009 - 01:35 pm: |
I had some nice emails from europe as well on the great info from Leonnie:
" Disproved that theory after many years of believing it, sadly to say.:
Everybody is looking forward to have her data or some of here data shown here to help us understanding te horse heart better, and why in contrary to many other animals the horse heart reacts so different.
It will be very interesting to see Leonnies numbers on EDV and SV and EF % during her step test and than the ECG datas on left ventricular ejection time as the horse is going fast and faster and how the horse heart actually controles a a stable EDV and even increased SV due to the increase EF % as the HR goes higher and higher. As in the situation of more volume moving in a certain direction through a certain opening may ask for a change in time differences, and as the heart valves are of agiven size and unlikely change the amount of blood , who can go through the time for more volume may have to go up , as otherwise the EF % would actually drop. In humans we see for the moment no such reaction ( healthy humans ) as the EF % either is stable or actually is increasing , This than shows a trend in a shortening of the LVET. If thsi does not happend we see an increase in CCT and immediatly after that famous 30 sec CCT a trend in lactate increase in the person. As oon I am back I will show actual tested results from live test and than we can compare them with Leonies data's . Will be very interesting to see, how and by what situation the data from horse to human actually will change and why the horse can maintain this high heart rates , even if with training the heart my get stronger and bigger.
Cheers Juerg .
Post Number: 25
|Posted on Saturday, April 04, 2009 - 04:08 pm: |
The resting heart rate was the same as a high heart rate horse and their exercise heart rates for the speed seemed no different, I will check my data. They just could not go to max as high.
Post Number: 26
|Posted on Saturday, April 04, 2009 - 04:50 pm: |
1. People that get very good maximum heart rates with very good monitors, such as the Televet 100 which is also an EKG machine and do it in a controled invironment, such as on a high speed treadmill, have never seen higher heart rates than 144.
I question the 255 as seen in equine literature, knowing that all it takes is to use the heart rate monitors under tack or missplace the electrode placement, or attach the transmitter to the horse, or, or, or....
2. Horses with maximum heart rates that are low turn into cheap claimers, this does not mean that they cannot win. They will rarely win, but they can still run a race. To me, it seems like throwing money and training time away.
4. Have not found differences between swimming horses max heart rate and running them on the treadmill max heart rates. Did that with a group of Standardbreds in California years ago. Same horses swimming as did the treadmill exercise. Swimming just challenges their lungs because they tend to breathe very labored and shallow, not stride for stride as they do across ground.
Someone pointed out that when you have a heart rate monitor in water, you will see a lot of artifacts, so were our numbers correct, I don't know at this point.
6. I have overtrained and caused progressive fatigue in several horses. I knew their maximum heart rate and did not find it to be lower than normal at that point.
7. The problem with testing young or old horses using the all out trial, continuous progressive test, or hill testing is that all of these testing methods are dangerously over stressfull.
My way of testing horses for maximum heart rate is done in an interval fashion, using 90 seconds of rest in between and on the treadmill on an incline.
Here is the testing proceedure that I use:
(note that SF means stride frequency and HR means Heart Rate. The first number is the time then the speed in miles per hour followed by a slash and then the slope in degrease)
MAXIMUM HEART RATE TEST PROCEEDURE
1:00 @ 4/0 SF HR
4:00 @ 8.5/2 SF HR
1:00 @ 8.5/4 SF HR
2:00 @ 15/4 SF HR
2:00 @ 18/4 SF HR
RECOVERY HR @ 4/4 0 30 60 90 seconds
2:00 @ 21/4 SF HR
RECOVERY HR @ 4/4 0 30 60 90 seconds
2:00 @ 24/4 SF HR (HOLD MAXIMUM HR FOR 10 SECONDS)
RECOVERY HR @ 4/2 0 30 60 90 seconds
I have used this on all ages of horses from 16 months on. It is done safely and always get a reproduceable maximum heart rate.
I have had a PhD at the University of Virginia, Mare Center want to publish this because in her opinion, this was the best method she had ever known to test for max heart rate. She had been doing the step tests on their treadmill before I gave her my testing proceedure.
Another part of this test is we record the room temperature and humidity as well as their feed intake in the past 24 hrs.
Juerge, until I get my breath by breath Vo2 monitor and my equine sports testing lab finished, which will include the Televet 100, I won't be able to share much more than my past records of the above maximum heart rate testing. I do have quite a number of horses that have done this test, over and over again throughout their training programs. I will have to look it up and put it into a spread sheet for you. Unfortunately, I don't have the time to do this at the moment.
Post Number: 1423
|Posted on Saturday, April 04, 2009 - 08:54 pm: |
Thankis Leonie for this interesting info, great work as many can now try this protocol.
Here 2 questions based on the info above :
1. What heart rate monitor system did you use for the testing of heart rate in the water, as till the Hosan d equipment is out this year , we had no way in humans to test HR through or in the water. Can you give me the companies name , who was in the horse coaching so much ahead of the human coaching by being able to test HR through the water. Name of the company and the brand of the model if possible.
2. As soon you have the VO2 testing you will se many different information on the gas exchange work on horses. What you not will have is info on the actual CO of the horse, as it is just used as a formula. In any animal including horses the VO2 tested is the result of HMV ( heart minute volume ) or CO = ( cardiac output ) times the (a-v ) o2 difference.
Now HMV or CO is depending on HR x SV . So as higher the heart rate as higher the CO by the same SV.
In hyumans we see with proper traiing an increase in heart size, which will ultimately end up in a higher EDV and by the same EF % in a higher SV. If they can maintain the same high HR than they ultimately will have a higher SV.
In some cases this seems to be possible in other cases we see that with increase in EDV and SV the max. heart rate they can sustain in a race ultimately droppes.
Till now there were many speculations why. We see now by testing EDV and SV life during na test, that one of the possible reasons may be a change in contraction strength and elasticity the heart combined with the pre and after load situation.
Thsi leads to a change in LVET and therefor potentially to a change in CCT.
Now in the past for many years there was in human coaching bthe believ , that as higher the HR ( or max HR ) as better the ability to race. Today we know , that a high HR will lim it the filling time of the heart, if the heart has a certain size, and it is not unusual to see top racers in all distances from 1500 m up with relative low max HR.
So some of the datas we would like to see from horses besides anectotal ideas and experience are really infos on changes in CO and EKG dftas combined . This would ultimately shed some light in a very interesting field of even genetic profiling and training induced positive changes.
Interesting will be to see, whether the V O2 testing will start on horse , where we were in humans about 40 years back . So we will wait with lot's of interest on the first VO2 datas collected in a horse.
Last but not least , if we would do the max HR test with a protocol like the one on horse with humans , we would miss many cardiac reactions. The step length in human testing needs to be longer than one minute , as in most of the clients, the HR will react as a functional reaction, and the actual CO will be slower to react.
I am surprised , that in horse , where dthe heart muscle is much bigger plus we may deal with spleen dumping some where in the step test, the HR and the actual mechanic of the horse will react that fast. There are similar test in humans for " max HR testing and max Watt testing ( Wingate ) but they all miss the main reactions of the human systems and are besides having a high tested HR and a high tested wattage , very little values to set up a training program or training zoning.
Thanks again for the inside view in horse testing and I hope many readers can learn from one or the other side and see the differences between this two Athletes , the horse and the human.
Post Number: 27
|Posted on Monday, April 06, 2009 - 04:53 am: |
Thank you for your interesting information as well. The heart rate monitors that they were using at that time were a Polars.
Post Number: 59
|Posted on Saturday, May 16, 2009 - 07:53 pm: |
Leonie, Juerg, Andrew please forgive me for not posting sooner but I got you now.
Of course how we could make PhysiFlow work for racehorses is a big question. Presently we are exploring how Zephyr’s Bio Harness could work with racehorses. You sir have started our glossary. An efficient way to maintain our FaCT Glossary is in http://www.rcswins.com where we can keep the Glossary up to date. Kevin Nally, VP Education/Racehorse Conditioning Systems is a PE/EP grad from Lock Haven U of PA. Kevin has posted in FaCT Forum and will probably agree to maintain our Glossary. This can be a huge benefit for our endeavors. With your posts Juerg most racehorse trainers will merely tune you out
Per your suggestion I went to the PhysioFlow thread in FF. Please give us “Cliff Notes”.
STF, FTS, LBP, defining structural vs functional changes is important plus many more definitions for physiology and pheeding terms.
We're agreeing now to adapt human 800 meter race training to 1 (+/-) mile racehorses. So we need programs/studies of longer duration? Of course long term development is outstanding but many racehorse trainers do not care about LTD. It’s all about “What have you done for me today?’
We need to most quickly turn our theories into real time results. Most present professional racehorse trainers will not get too excited about our ideas because it will mean more work for them.
Our first Racehorse Exercise Physiology Seminar at Rutgers (REPS I) can come together but it’s a while away. We want a small well prepared group to get down on some large opportunities. Participation by both the t-breds and standards is desired.
Rutgers is wonderful. Karyn Malinowski PhD can help us set up REPS 1. She’s a harness owner, trainer and driver and on Rutger's team.
Polar has been giving me shit-fits. There is a new generation coming and we hope it gives us more consistent results.
Leonie, Jureg, Andrew.
So for years Leonie and I worked-out Allentown with specific heart rates, speeds and intervals. He’s only paid his way if we value the benefit to our learning.
Andrew & Juerg wanted us to work Allentown at LBP-15-20 now they suggest we do our steady-state at “Just below LBP”. Which is it?
Leonie & Juerg did not know the LBP but we were doing a lot of work between 160 and 180 beats per minute. Allentown was racing at a low level. He wants to be in higher classes and win more money. His last win was on a ˝ mile track was 1:58 in November. We are pointing for him to do a 1:52 on a mile track. Professional harness trainers would exclaim, “Unfuckinbeliavable”.
In a recent off-forum exchange Andrew stated,
“STF and FTF are poor names for muscle fiber types. STF used to be called Red Fibers, described for their increased hemoglobin supply, as they have more mitochondria, and better oxygen utilization. They appear red under a microscope.
When it was found they fatigued at a slower rate, they were termed STF, which caught on, and has been used ever since.
Actually they have nearly the same ability to contract as quickly as FTF. The difference is so small, that it is not noticeable in the movement patterns we are talking about. This is because during running we don’t contract our muscles as fast as they are capable of moving, due to the forces required for forward propulsion etc. The coordination that Allentown requires is more a function of teaching his muscles to coordinate their contractions so as to produce the desired force for pulling the cart, and to RELAX fast enough so that he can get his hoof back into position for the next stride. Coordination of repetitive movement, cycling and running are examples, is all about teaching the muscles to relax after the coordinated contraction.
Try sitting on a bike and spinning your feet as fast as you can, to see what cadence you can achieve. Don;t use any resistance, and you will see that you start to bounce up and down . This is not that you can't contract quickly, but you can;t relax your quads fast enough to make a circular pattern with your legs. Practice this over time, and soon you will be able to ride for extended periods of time at higher and higher cadences. NOT by switching muscles fiber types, but by developing coordination of the muscles you have.
1. Who is Allentown?
2. Andy, are you saying that STF (Slow Twitch Fibers) can be equally effective in an 800 meter race as FTF (Fast Twitch Fibers)?
3. Show me the science (money)?
Soon there will be an Allentown thread.
Post Number: 1525
|Posted on Monday, May 18, 2009 - 08:16 am: |
Thanks as usual for any comments on our Forum.
I completely agree with your statement, that no horse trainer will read or go for our , resp. my Forum notes and ideas.
There are not only horse trainer who do this, but many other trainers and coaches as well.
This is the beauty of our technology on computer forums , as well as with other media ideas. We can this days correspond with nearly any body on this smaller and smaller world , and can exchange ideas and thoughts. All of this we do here as well, and as in any other Forum , we alwasy have regular readers and one time hits. Over the past years we had many many great contacts over this Forum , and who ever likes to participate is more than welcome to help us to go forward with ideas and thoughts. The same invitation is for horse coaches as well as for any other coaches and readers. We hope we can fill in some new ideas or at least some additional discussion to existing and new ideas in any direction we think some of our equipment will lead us.
So again thanks for your feedback and summary .