Recently, I reexamined the results from a V02max test I took in 2009 that also provided information about RQ and sugar/fat burning ratio at different intensities. I wore a mask that measured the amount of C02 being exhaled and the software can determine how much fat you're burning. I also wore a HR monitor. At the time I was pretty concerned with looking for a deflection point in the HR graph somewhere in the neighborhood of the 180 formula. I was 48 at the time, so there should have been a plateau and deflection around 132. There was one at 133-134 bpm. There was also one at 142 bpm. I don't remember really examining the sugar burning graph. I must have, but don't really remember giving it a lot of weight. There was some discussion, but I don't remember talking specifically about a deflection point on the sugar graph.
What prompted me to reexamine the data was the following question (that I couldn't find an answer for):
Let's say I warm up slowly, and get up to a pace that brings me to MAF HR, then hold that pace steady. My HR will remain steady for awhile, but will start to rise as I hold the steady pace. While holding this steady pace, will the amount of fat/sugar being burned remain the same as HR rises?
I'm thinking that if the amount of fat and sugar being used remains the same, then even though HR has risen by 10 bpm, I'm still using the same mix of energy systems. I'd still be at MAF, even though my HR is 10 beats over it. MAF heart rate really represents the point where the anaerobic energy system begins to kick in a little bit. It's the plateau and subsequent rise in sugar burning that defines it, not the HR.
I couldn't find an answer. So, I thought I'd take a look back. Below are relevant areas of the sugar burning and coinciding HR charts from the test
SUGAR BURNING
HEART RATE (180-age at the time= 132 bpm)
One can see a beautifully defined plateau and deflection in sugar burning. From the time I hit 130 bpm until I reached a plateau at 142 bpm, the sugar/fat ratio remained at approximately 38% sugar/ 62% fat, regardless of increased intensity and rising HR. In heart rate, there were plateaus as shown in the graph. My calculated MAF of 132 was near the bottom of this zone. The HRR graph showed a deflection at 133-134 bpm.
From this data, Is it too much of leap to think that if I held a steady pace once I reached MAF heart rate that, metabolically, I'd still be at MAF despite a rising HR?
Is MAF really more of a zone, and not a specific HR? In the chart, the 38% sugar/62% fat covered a zone of 130-142 bpm, or about 65-71% of MHR (198 bpm). 65-70% MHR is considered in most HR programs as the fat-burning/easy zone. My HADD training every day easy running HR for my MHR of 198 is 145 bpm or lower (73% MHR or lower)
Could I have considered in 2009 that 142 bpm was my MAF? Since that was the deflection point or end of the plateau in sugar burning.
Here's the relevant portion of the graph from my most recent treadmill test in December 2014. I was in horrible shape at the time:
TREADMILL TEST December, 2014
There's that same 8-9 beat spread between plateaus as seen in the other HR graph, and almost at the same points—just 2 beats lower than the 133-142 bpm spread. I haven't had another V02max test, so really am not sure where my sugar-burning graph would look like at this point, but the HR is doing the same thing. 5 years later and not much change. Though the upper plateau in my first treadmill test in 2011 was much higher (146 bpm). Perhaps because I was in better shape and was under much less stress in March 2011, or the treadmill test I created is just kind of wonky and unreliable.
Here's what's running through my mind as an experiment. I'm thinking that I can still remain with the 132 MAF I'm currently using, but on hard days do runs in which I warm up to MAF then hold the speed and not slow, and let my HR rise. I'm pretty certain the sugar/fat ratio isn't going to change much. If it didn't change while intensity increased in that range in the V02 max test, a steady pace shouldn't make it rise either. I'll continue to do MAF tests the same way as I have in the past. If my MAF tests improve, then at the very least the experiment would show that the practice isn't detrimental to aerobic development... in my case. I must note that Dr. Maffetone has reported, that in some people with poor aerobic development and awful resting RQ, going over MAF even by a few beats has been detrimental. So, I'm risking that. But I'm really curious.
I'd also like to note that in past runs that approached 2 hours or more, and run at a steady pace starting well below MAF, I've noticed a spike in HR at around 2 hours. The HR rises steadily through the run and then suddenly a huge jump. I've theorized that at that point the slow twitch fibers are beginning to become exhausted and more anaerobic fibers are being recruited. I remember reading about some science about long runs, and they mentioned that this is what happens after a certain amount of time on your feet. As I do this experiment, I'm going to keep an eye on whether or not this spike occurs as I approach 2 hours.
That's it!
EDIT ON 9-8-15 :
I did a brief treadmill test today not surpassing MAF +28. I found the almost same plateaus happening as in December 2014, just a little lower for one occurring around the calculated 180-age (currently 126 for 180-age), and a little higher for upper plateau (a little more defined than the one at 130—with 5 data points).
Here a chart:
I thought that if heart rate is inçreasing Jimmy then a higher proportion of sugar is getting burned even if youre going slower never mind constant pace ...unless its fatigue or dehydration or do they make you burn more sugar ...im sure Dr P has a theory ....havent seen any studies to say otherwise
The break in the chain under these conditions occurs not in Oxygen transport, but Oxygen demand, i.e. at the top of the chain. During the eccentric exercise, as muscle damage occurs, the legs are forced to recruit larger, less economical muscle fibers. These fibers require a greater amount of O2 to exert a given level of power and the heart rate goes up for a given power output when the more economical fibers begin to fatigue.
In fact, type II fibers require ~twice the O2 for a given power output. Therefore, small fiber shifts result in relatively large differences in heart rate for a given power output (Coyle, 1992)
http://www.endurancecorner.com/decoupling
Interesting stuff, Shondek. I know that sugar-burning will most likely rise at certain point if Type 2 are recruited to compensate for exhausted Type 1. Dr. Phil has said in this very forum that we need to spend time running at MAF for best results. At MAF, you're more likely to be using some Type 2 fibers as it's right in the area where they begin to get recruited. I do believe these particular Type 2 can be made "more aerobic" as they're trained. Studies on long runs show this recruitment, and it's the training of these adaptable type 2 that not only add to endurance but speed.
Training by heart rate for so long, I understand that the drift upwards can't just be dehydration. If I'm fatter, my heart rate tends to rise faster, most likely because my fat suit is keeping heat in. There's a point in every run where the HR seems to spike, or you have to slow considerably to stay at same HR.
In a V02max test, there really isn't enough time for fiber exhaustion. Especially when I was in the range of calculated MAF. That extended plateau in Fat/sugar burning through a 10 bpm rise in intensity says to me that anywhere in that zone is pretty much the same metabolically, as far as starting out a run. If I start at 140, it's the same as 130. I My current thinking is that my MAF heart rate at that point in time was 142, and not 180-age (132 bpm), if you base it on the deflection in sugar burning and take the corresponding HR. I have a high MHR (198-200), and it hasn't changed since I started running.
Lately, I've been experimenting with starting out at 132 bpm and holding a steady pace and not worrying about a ceiling. I've been seeing progress. My HR might end up at 151 in 80ºF after 75 minutes, but my breathing hasn't changed. The 151 bpm at the end of the run that started out at 132 bpm definitely feels easier than a run that I started out at 151 bpm. In 80º and in the current fat suit I'm wearing, I speculate that most of the rise at this point is due to heat dissipation and a dehydration. How much more sugar am I burning after 75 minutes in those temps at the same pace? I really don't know, but I don't think too much more. The only way to know for sure is to be gas-tested for a couple of hours at the same pace. Can't find any studies or info about such an experiment yet.
I'm going to look more into the Friel stuff. Thanks.
This is probably the opposite of what you are researching
ny measurements of blood lactate in a cold ambient temperature, therefore, must be treated with some caution. Using heart rate as an index of training effort could also be misleading, as lower heart rates will be recorded for a standard exercise bout when undertaken in the cold as opposed to *208C (Beelan and Sargeant, 1991; Febbraio et al., 1996b; Weller et al., 1997; Layden et al., 2002). This is likely to be caused by the peripheral vasoconstriction associated with low skin temperatures in cold environments, which would shunt more blood to the central volume (Rowell, 1983), increasing venous return and thus lowering heart rate.
This is probably the opposite of what you are researching ny measurements of blood lactate in a cold ambient temperature, therefore, must be treated with some caution. Using heart rate as an index of training effort could also be misleading, as lower heart rates will be recorded for a standard exercise bout when undertaken in the cold as opposed to *208C (Beelan and Sargeant, 1991; Febbraio et al., 1996b; Weller et al., 1997; Layden et al., 2002). This is likely to be caused by the peripheral vasoconstriction associated with low skin temperatures in cold environments, which would shunt more blood to the central volume (Rowell, 1983), increasing venous return and thus lowering heart rate.
Is this a fancy way to say I can run faster at the same HR in cold weather? My best marathons were in the 40's. In cold weather I can still reach MHR, though.
Joe Friel !?..Hmmmm....The rivalry of endurance coaches ..rule no 1..Never mention the opposition
' 'Allen used a fairly complex formula to determine an aerobic endurance training heart rate zone based mostly on age and experience'
http://www.joefrielsblog.com/2010/04/mark-allens-training.html
Just saw your input Jimmy lol
Joe Friel !?..Hmmmm....The rivalry of endurance coaches ..rule no 1..Never mention the opposition ' 'Allen used a fairly complex formula to determine an aerobic endurance training heart rate zone based mostly on age and experience' http://www.joefrielsblog.com/2010/04/mark-allens-training.html Just saw your input Jimmy lol
I read the blog thinking "why isn't he mentioning Maffetone and what complex formula?", then I looked at the comments and realized I read the blog and left a comment over 5 years ago!
In addition to these variables geometry dash lite, the rate of burning is influenced by your genetic composition, topography, degree of fitness, and the time since your last meal. The legs are compelled to use bigger, less efficient muscular fibers as a result of muscle injury sustained during the eccentric exercise. Every run seems to have a peak in HR at this point, or you have to slow down significantly to maintain the same HR.