PS – Your VO2 max is about 38. You can look up how good this is based on your age. This is an excellent and traditional marker of how well developed your aerobic energy system is.
russes011
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Participantrusses011 on March 18, 2021 at 11:08 am · in reply to: Metabolic efficiency test results: Improving poor fat utilisation #52172Participantrusses011 on March 18, 2021 at 11:00 am · in reply to: Metabolic efficiency test results: Improving poor fat utilisation #52170
Phil,
Your test appears to be a combined VO2max and RER (%carbs/%fat) test. Optimally, these tests are done on separate days, but combining them is common.
It measured your VO2 max and from that it calculated your HR zones based on population averages. This is about as accurate as using your MaxHR and then taking a percentage of that. This is a common and accurate method, on average, as long as you gave it 100% max effort at the end–your VO2 curve flattened out at the end but I couldn’t tell for sure.
It also measured your RER (%carbs vs %fat burned) and presented the results by HR zone. You do not have a crossover point (you always burned more carbs than fats, in the HRs measured). Your Faxmax was about 45% and occurred in your lowest zone with a HR in the 150s. Keep in mind that you would probably burn more fat at even lower HRs, so this Fatmax isn’t so useful.
There was a glitch at the start of the test, perhaps the tubing wasn’t sealed or connected properly, and as you mentioned you started out too quick and slow downed. If the test is repeated, they should measure your data at rest for some time, and once reliable curves are established the pace should be increased slowly, especially in the beginning. With better low HR data curves you would probably have had a crossover point, say in the 130s. (A bonus metric with measuring your RER at rest is that it can give your basal metabolic rate in calories per day via the Weir equation).
Keep in mind that your crossover point does not determine the AeT and your AeT does not determine the crossover point. They are unrelated metrics (I’ve recently learned this).
I will post again below regarding my recent thoughts on the following:
1. AeT definition and determination
2. Crossover Point, an/or METs in general
Hope this was helpful.
I will leave any exercise/training prescription to the moderators, UA books, other participants, and online articles.
Steve
Participantrusses011 on March 16, 2021 at 5:32 pm · in reply to: Metabolic efficiency test results: Improving poor fat utilisation #52101AshRick, The above link partly answers your (our) question.
ParticipantAlso Following
Participantrusses011 on March 16, 2021 at 9:56 am · in reply to: Metabolic efficiency test results: Improving poor fat utilisation #52080Phil,
I feel like there is something fishy is going on with your MET results. I would suggest being as sure as possible with your ‘diagnosis’ before you spend a few months with the ‘prescription”.
Specifically, how did they determine your AeT? Gas exchange usually uses the respiratory quotient method where your AeT HR is when you’re by definition at 50% carb utilization. (am I wrong here?)
Perhaps they gave your AeT based on the lactate method. I bring this up as a possibility because you also had a AnT test, which I think usually uses the lactate method.
(I feel like the lactate method is less reliable for determining AeT, but am not sure. For the UA training method I believe the gas exchange approach is most useful. So if this is the discrepancy your AeT HR is perhaps much lower than you think and correlates to your experiences running in the field)
If you have the time, I would cross check your presumed AeT HR (perhaps both the lactate method one vs the gas exchange one, if you have both) and see how it compares to the UA AeT HR drift test.
Also, I believe performing both an AeT and AnT test on the same day may confound the results of each. I think they often suggest they do them on difference days.
You could also attach a photo or pdf of your MET so we could see it. (scrub your personal info before doing this)
— Steve
ParticipantMy hunch is that the result of Scenario 1A would be that Fred and Chad would finish at the same time. I think this because the differences mentioned in the scenario are just not enough to have an effect on the outcome. Shooting from the hip here, but I suppose AeT is not a static metric (it collapses after a certain distance), and that after 3-4hr of running (say 20-25 miles) the factors that determine success and performance are mostly unknown, or at least misunderstood. To summarize, I think exercise physiology turns to exercise pathophysiology after a certain distance or time running.
ParticipantThomas,
I agree with you that my above analysis is too reductive to be truly valid or predictive. That said, I think it’s still conceptually sound, at least from the level of a freshman physiology course. One key question, however, that you and others astutely bring up, is whether Fred actually had a higher AeT than Chad at the start line due to his fasted training—or, more generally, did Fred have an advantage because he was more fat adapted? For example, if his AeT was 20% higher due to his fasted training he could have at least tied Chad, even without any carbs during the race.
IN GENERAL, I do not think Fred was more fat adapted, nor do I think Fred experienced any significant ketosis prior to the race.
I understand training increases your AeT regardless of diet. I also understand that a ketogenic diet, or even a high fat diet without ketosis, could shift your respiratory quotient downward, and presumably your AeT upward. But Fred (like Chad) was on a 50/50 (by calorie) carb/fat diet, which is twice as many carbs than fats by gram. Was Fred’s training without carbs, in and of itself, enough to raise his AeT higher than Chad’s? My hunch is no, since his overall diet had enough carbs to replenish most of his glycogen stores, and most of his training was likely in a time range (1-4hrs) where his internal carbs were still mostly available for use—in effect his muscles never really experienced a true low carb state, and didn’t really experience much ketosis, if any.
Let’s say instead Fred fasted for the 12hrs prior to every training session, the currently popular, “rest low, train high” approach to ramping up your AeT via fat adaptation (as you mentioned). I, unfortunately, don’t think this would have made a real difference either, at least from a glycogen point of view. Fred’s consumption of Chad’s 50/50 diet the rest of his day should have been enough carbs to (mostly) refill his glycogen stores, at least to the same degree as Chad, and not eating breakfast prior to training, eg, is just not enough of a low carb state (given his decent glycogen stores and that most of his training would only be in the few hour range and at low intensity). I presume this approach is too homeopathic to be effective. I understand that the fasted training approach is on a spectrum of efficacy—say his dinners were no carb, or he performed doubles off carbs—but this is too far from Scenario 1A.
Steve
ParticipantYes congrats on Leadville!
Yeah, HR is interesting. I feel like there is a psychological component to keeping one’s HR low while running at low intensities. Relaxation (mind and body) and breath control probably helps lower the heart rate and keep it low. Not sure about all this but I do know that just thinking about exercise, even before your first step, causes adrenaline to increase, which primes you for action by increasing your heart rate. Also I bet just seeing a hill in the distance may give you a shot of adrenaline even before you get there.
ParticipantIn order to win, Chad and Fred will run the race at AeT. Since they ate the same diet and have performed the same work-outs, for simplicity sake let’s assume their AeTs are equal. They have full and equal glycogen and fat stores before the race begins. In summary, they run most of the race at the same AeT, and therefore at the same HR and speed. Aerobic metabolism supplies the ATP, and since they’re at AeT, by definition 50% is from carbs and 50% is from fat (they are at the crossover point). From a biochemical point of view, carbs and fats are equally efficient at producing ATP, per unit of oxygen: they both produce about 5 ATP per O2 molecule. Both Chad and Fred have unlimited fat stores. At the start line, Chad and Fred both have about 2000cal worth of glycogen.
Let’s say they burn 4800cal during the 6hr race (~800cal/hr@10min/mi), which is about average or so. Since they have the same AeT and are both running at their AeT, by definition they’re using the same amount of carbohydrates per hour (400cal), at least until Fred runs out. Fred, with 2000cal of glycogen, runs out of carbs at ~5hrs. Chad, in essence, has unlimited access to carbs during the race, thus preserving his glycogen stores. Overall, Chad was best able to spare carbohydrates during the race, which is perhaps the main factor that determines onset of fatigue. Note, however, that without carb supplementation Chad’s ability to spare carbs would still be equal to Fred’s, since they both have the same AeT. Chad wins the race because he could maintain his AeT, while Fred has to slow down around 5hrs because he can no longer maintain AeT, which by definition requires 50% carbs as a fuel source. If the race was say ~5hr long, they would have tied.
Carbs are always important on race day—ie, the carbs you already have within you. Carb supplementation, per se, may or may not be important on race day, depending on the distance (and intensity level). Chad’s supplementation would not have helped him win the race if it was say ~2-5hrs long—assuming they raced solely at AeT, which on average is the fastest one can race at these durations, and neurological factors are excluded. To maintain AeT beyond about 5hr, a carb fueling strategy is required. That’s not to say one can’t run way beyond ~5hr without carbs, but that they will be doing this at a pace below AeT. This underscores the importance of improving one’s AeT.
(I hope this reasoning isn’t too reductive to the point where it makes my argument false)
ParticipantThomas,
Thanks for pointing out my error regarding saturation always being 100% during exercise, or at least my oversimplification. Honestly I noted that after I originally posted but didn’t go back to edit my post. As you know (and EIAH aside) most normal folks have an O2 sat around 95-100% at rest. With the potentially tremendous pulmonary compensation we all have during exercise (in the order of 8-fold) this O2 sat usually increases a few points, say putting most at 97-100% during exercise. As I believe you understand, my point was that the oxygenation of the blood by the lungs, specifically, is not a common rate limiting process during exercise. Therefore devices that purportedly increase the lungs ability to oxygenate (or even ventilate) are probably not useful. For example, breath right strips don’t work, aside from their placebo effect.
I was not aware of EIAH–thank you for pointing it out to me! Very interesting. It seems that in athletes with stupendous cardiac outputs from extensive aerobic training, their hearts (aka blood flow) may actually outpace their lungs ability to oxygenate their blood when they are close to maximal efforts. (This also can happen in children, who have yet undeveloped lungs compared to their hearts). It would be fascinating to speculate about the cause but that would be way way out of my league. It reminds me of the finish to Ravel’s Bolero, when the frenzied crescendo becomes disjointed and eventually falls apart.
— Steve
ParticipantHaving read a little bit more about muscle loss, my above recommendation to keep eating a high amount of protein is incorrect. To lose muscle mass one needs to have a negative nitrogen balance. To achieve this your protein intake has to be relatively low, that is in relation to the amount of endurance exercise you are performing. I would suggest the standard RDA protein intake of 0.8g/kg, which would establish a negative nitrogen balance if you have a good amount of endurance training load. As mentioned, endurance exercise in itself can promote a negative nitrogen balance, and a lack of resistance training can do the same.
ParticipantSCENARIO 1A:
Fred and Chad are twins. They always train together, have the same body composition, and equal anaerobic thresholds.
They both eat the same diet, with an equal number of calories from carbs and fats.
Fred only drinks water during training, while Chad consumes carbs every 30 minutes.
Similar to training, Fred only drinks water during races, while Chad consumes some carbs every 30 minutes.
They compete in a 6hr race on a flat course. There is an aid station every 2 miles with water, a drink that supplies both simple and complex carbs, and energy gels.
Who will win the race? Who has the advantage and why?
(What I’m asking is: are carbs or fats the most efficient fuel for aerobic metabolism?)
ParticipantI agree with both Scott and Thomas.
Lean muscle mass at baseline (ie without being on a muscle building routine) is a prized commodity. I would not give it up lightly. It not only makes you more of a powerful athlete, it can keep you healthy through strength, as well as lean due to its high thermogenic effect. And, if I’m not mistaken, it will also boost your VO2 max, because of all that muscle consuming oxygen. As Scott points out, I would truly review your need to reduce muscle mass, perhaps talk to some trusted friends to see if they think it would be reasonable.
If you would like some prescriptive advice on how, specifically, to lose muscle, try the following ~6 month cycle:
Put a pause on any dedicated strength training.
Start building an aerobic base with progressive, long, Z1/Z2 distance running/hiking, as delineated in UA books.
Prioritize 2 long workouts per week, building up to 4-8hrs each, all at low intensity (eg hiking, long bike rides, run/walks).
Key workouts will be those over 3hr long, because past this point your body, in general, will ramp up using your own muscle as an energy source, in order of up to 1/10 – 1/5 of the calories you burn.
I want your body to be like: “hey, if I had less muscle, all this constant, easy movement would a lot easier!”
Paradoxically, I would continue to eat plenty of protein, say the usual rec of about 20-25G per meal or per 3hrs. I don’t have any specific science saying this will help or hinder muscle loss. I presume for rapid muscle loss you could cut out most of your protein, but this is not recommended, and is likely unhealthy.
Regarding overall calories–would just keep the same amount you are now, or just eat to hunger with wholesome foods, if your have the resources and time to make it work.
(unique goals like this may warrant consultation with a nutritionist, because sometimes it hard to know when to stop, once the muscle loss gets ramped up, and you may need an objective outsider to tell you when to sop or slow down)
Plan B: just drink tea with a little milk for a few months (and chain smoke cigarettes)–I think this is what christian bale did to lose 60lbs for the machinist. (JK–don’t do this)
ParticipantDear Dada,
I read the instagram link you provided as well as the author’s responses to the comments. I also listened to one of his podcasts. He appears to have a bruised ego because Steve didn’t have the time to do a discussion piece with him for a magazine article–so he’s attacking UA’s concept of ADS on Instagram. I don’t think a debate with this person is warranted or advised. Nevertheless, Steve or Scott having a debate with another open-minded, thoughtful, and professional person regarding the physiology and semantics of ADS would be great.
1. The lack of peer-reviewed articles on the topic neither proves nor disproves it’s validity. ADS does possess inherent logic, however, and I presume empiric evidence based on UA’s coaching experience.
2. Just because all movement has an aerobic component, does not mean everyone’s aerobic systems are equally developed. Compared to a seasoned ultrarunner I’m aerobically deficient, but compared to a coach potato sprinting out the door I am not. It all depends on the point of reference.
There’s an old adage in running: “have a problem?: just run more” (as in: are you overtrained, injured, plateaued?: just run more). Countless high school cross country coaches over the decades have probably mumbled these words to complaining students: just run more. What does this mean? It means that if you have a problem with your training the answer often comes back to you having an insufficient, or inconsistent, base: ie ADS. That is, the solution to most issues is just to drop the intensity and build more mileage: simply run more. Running more, or building more of a weekly base, is often part of, or all of, the solution, regardless if you’re hurt, plateaued, or overtrained. I feel that many, if not most, coaches and athletes have experienced this phenomenon in their own careers. All that UA is trying to do (I presume) is codify this old adage so that it may be more readily communicated and measured, hence the term ADS. I commend them on their efforts–it will be, and has been, an uphill battle for them to convince many, but hey, you know something: they’re good at going uphill.
Steve
ParticipantAeT, according to UA, is the crossover point when one is using equal parts fat and carbs during exercise. I presume they like this metric because they believe that for prolonged outdoor exercise it is possibly more efficient, or simply more practical, to be able to exercise while remaining to the left of this point (more fat usage). Therefore shifting this point to the right by lots of easy training mileage is the goal.
The amount of fat vs carbs one uses at during exercise, in general, is also determined by one’s diet. The crossover point mentioned above could be ‘confounded’, or shifted right or left independent of training status or fitness. For example, if I’m on a carb rich diet my respiratory quotient (the metric used to determine fat vs carbs) will shift towards a more carb centric result (ie shift the crossover point to the left—a more deficient AeT), independent of exercise.
So how about anaerobic vs aerobic? This system, unfortunately, doesn’t overlap as reliably or conveniently with the above crossover point. In general, the point where lactate starts to appear in the blood is often thought to correlate (roughly) with this crossover point. There are probably too many variables to generalize here, including diet and training status, as well as the chronicity and type of each. Note this is not the point where aerobic vs anaerobic is 50/50 (equal parts of energy production). To simplify, this lactate crossover (or appearance) point may be better thought of as the point where the aerobic system loses control of the anaerobic system.
Even when there is no lactate in the blood the anaerobic system is still in play to a significant degree. In fact, during all exercise both of these systems are always in play, and even more so for exercises that are not steady state, like trail running where the terrain is variable. During all exercise the byproducts of anaerobic metabolism, which are themselves fuels, that are built up in the cells, especially during minor to major bouts of more intense efforts, are “cleared” by the aerobic system. If the byproducts of anaerobic metabolism are too great, however, they spill into the blood in the form of lactate. Exercise can improve ones ability to clear these byproducts while they are still in the cell and prevent them from entering the blood stream; exercise can also improve one’s ability to clear these by products once they are in the blood. Therefore, simply playing housekeeper to the anaerobic system is another reason why exercise can shift the AeT to the right, at least when tested with blood lactate or ventilatory effort.
Finally, aerobic metabolism can be fueled by either carbs or fats and which one does this best remains uncertain. The answer is probably: it depends. Nevertheless, stored fat tends to be the most practical/efficient source for prolonged efforts, depending on exercise intensity and dietary plan during these efforts.
So what’s my point with all this fuzzy half-truth spray? I guess it is that the proof is in the details and semantics matter when arguing about these topics, and it’s important to be on the same page.
FODS may not be the optimal name for the phenomenon we’re referring to since a shift in the AeT to the right (ie an increase in the AeT HR or an AeT HR within 10% of AnT HR) is not a fat dependent process PER SE, at least when lactate, ventilatory parameters, and likely HR drift are used to measure one’s AeT. In other words, folks who often fuel long outdoor endeavors with constant carbs like during ironman triathlons and the tour de France are not “aerobically deficient”. I believe it probably doesn’t matter if your diet is carb based or fat based when it comes to AeT and aerobic base, as long as you have become well acclimated in training to what your diet will be like during your event.
On a different note, I think the verdict is still out on whether work below AeT, or work above AeT, or a combination of both, is the most efficient way to improve one’s ‘aerobic base’, even when things like AeT drift, 10% separation, respiratory quotient, lactate levels, and/or ventilatory rates are used as surrogates to confirm it. A balanced approach, that gets more intense and specific with time may be best. Having to achieve a certain threshold from an aerobic viewpoint before it being optimal to start polarized training seems a bit too restrictive (not sure). These points speak to the utility of calling it base deficiency syndrome: I’m not a fan because what base are you referring to? Aerobic base, anaerobic base, or perhaps both, since they can’t truly be separated—eg how can you truly developed one’s aerobic base without stressing it with enough anaerobic byproducts to make it more efficient at clearing them, which is one of the fundamental components of having a good aerobic base? (Note: I’m leaving out the fact that there is yet another enzymatic pathway [AMPK] that can develop one’s aerobic base—one that is stimulated by HIIT, and not long slow distance per se, and unrelated to the housekeeping).
In summary, I’m not a fan of the words deficiency or syndrome, but UA’s use of the term ADS is perhaps the best compromise considering the points I try to make above.
Sorry this as so long winded and didactic (and perhaps wrong in spots). I also want to post later about why I think Koop is both wrong and right.