I think you misunderstand what I meant. Walking isn't the mental breakdown. For me the "reward" of a little walk is mental encouragement/focus to maintain my steady pace until I get to the aid station. I don't walk because I have to, I walk because I earned it. I may not NEED to walk to get good hydration and nutrition but it helps me to drop to a brisk walk. The execution problem I mentioned is letting yourself get away from whatever length break you told yourself you would use. At IMCDA I never let my breaks extend. I'd walk briskly for 10-15 steps ( I wasn't counting), grab what I needed, and then get back on my horse. Had I decided to walk until I felt like running again I would have been on that slippery slope you outlined. So in my opinion a well-planned walk/run strategy is only risky if you can't stick with the program - and that is most likely a mental weakness at that point in the day.
Posted By Chris Whyte on 09 Jun 2010 12:14 PM
Actually, it's not a diversion at all and here's why:
For the exact same reasons you tell yourself to execute a walk break strategy, you might be better off running the entire way. First off, I've heard several people claim before that you need to walk the aid stations in order to get properly fueled. That's simply not true. I've done both and neither approach has allowed me to fuel better.
Secondly, Joel, you just said that you need to walk for mental (focus) reasons yet you also claim that making the mistake of walking and walking more often as the race progresses is a mental focus breakdown. This is exactly my point. So, you're doing something, ie, walking, for (good) mental reasons that also just happens to be the result of a mental breakdown.
Why do the one thing that happens to be the cause of what you're trying to avoid in the first place (a mental focus breakdown)?
I think you misunderstand what I meant. Walking isn't the mental breakdown. For me the "reward" of a little walk is mental encouragement/focus to maintain my steady pace until I get to the aid station. I don't walk because I have to, I walk because I earned it. I may not NEED to walk to get good hydration and nutrition but it helps me to drop to a brisk walk. The execution problem I mentioned is letting yourself get away from whatever length break you told yourself you would use. At IMCDA I never let my breaks extend. I'd walk briskly for 10-15 steps ( I wasn't counting), grab what I needed, and then get back on my horse. Had I decided to walk until I felt like running again I would have been on that slippery slope you outlined. So in my opinion a well-planned walk/run strategy is only risky if you can't stick with the program - and that is most likely a mental weakness at that point in the day.
I didn't misunderstand what you meant. I fully realize that in an ideal situation where you plan a run/walk strategy walking is the supposedly the "reward." However, it is also a fact that walking is ALWAYS the result of a mental breakdown too. My point is that what you think is a reward will quite often turn into mental breakdown because nobody out there really has their wits about them and if they do then they're not running hard enough, imho. As you said, it's a slippery slope. You, specifically, might be disciplined enough to pull it off but I'm not focusing on the exception, I'm focusing the rule. I truly believe that most people don't.
Look, let's be honest here, if your goal is to finish in the fastest possible time then there is no ideal IM run situation. An ideal IM run is digging so deep it freakin' hurts like there's no tomorrow. Think about it, how many people really don't fade that much on the IM run? Relatively speaking, it's extremely rare. IOW, I can count the number of people who really stick their plan on maybe 2 hands. Keep in mind that I'm also considering the people who lie to themselves after the race and say, "I stuck to my plan" (and then you look at their data).
Btw, if we're really talking/debating about walking briskly for 10 - 15 steps then let's move on. That's really not walking...
Bear in mind that that not only changes in grade are used to calculate the physiologically relevant pace of NGP. As with NP in cycling, an exponential weighting step is utilized that is based on the relationship between intensity and lactate accumulation. So, not only is the NGP faster than the raw reported pace as a result of a positive grade, in some circumstances, an effort that has a component above the “threshold” will result in a more metabolically costly effort than indicated by the raw pace.
*****************
You don't need to theorize anything. It's pretty straightforward given that it uses and exponential weighting step. Clearly you're getting more than variability of terrain. Now we can debate the accuracy of what you get as far as metabolic cost is concerned but I'll continue to emphasis that if you believe rTSS has significance then you MUST believe that NGP has significance. You cannot question one without questioning the other.
I agree rTSS has significance (otherwise, why am I bothering to download my runs into WKO?), but I don't think its nearly as accurate as TSS. Pace is still just an outcome of "power" that you generate and not a direct measure of the power itself. NGP certainly tries to account for change in elevations, but that's not the whole equation. Wind and road surface will have impacts as well (and frankly, give me a freakin hill over a 20mph head wind any day!- sorry I had to vent).
But let's assume for the moment that you can remove all the other variables from the equation so you can just look at the impact on total average pace that brisk walk break has on you metabolically. I suppose one could do a treadmill test with and without the walk breaks to see if a person could run a faster overall pace with the walk breaks at a lower heart rate? I realize HR isn't an exact or perfect metric either- but the real question here is if the breaks really do offer a physical benefit to allow you to run faster overall, or if it's more of a mental game.
I wonder if a similar test has been done somewhere? There are sub 3 hour marathoners using run/walk based on coaching advice from folks like Bobby McGee, so I gotta think some doctorate student has a study on it somewhere!
I didn't misunderstand what you meant. I fully realize that in an ideal situation where you plan a run/walk strategy walking is the supposedly the "reward." However, it is also a fact that walking is ALWAYS the result of a mental breakdown too. My point is that what you think is a reward will quite often turn into mental breakdown because nobody out there really has their wits about them and if they do then they're not running hard enough, imho. As you said, it's a slippery slope. You, specifically, might be disciplined enough to pull it off but I'm not focusing on the exception, I'm focusing the rule. I truly believe that most people don't.
Look, let's be honest here, if your goal is to finish in the fastest possible time then there is no ideal IM run situation. An ideal IM run is digging so deep it freakin' hurts like there's no tomorrow. Think about it, how many people really don't fade that much on the IM run? Relatively speaking, it's extremely rare. IOW, I can count the number of people who really stick their plan on maybe 2 hands. Keep in mind that I'm also considering the people who lie to themselves after the race and say, "I stuck to my plan" (and then you look at their data).
Btw, if we're really talking/debating about walking briskly for 10 - 15 steps then let's move on. That's really not walking...
Thanks, Chris
I guess we're going to have to agree to disagree here. I ran a respectable marathon at IMCdA last year (3:14 - 25 OA fastest on the day) and walked at probably 22+ aid stations. Hell, I even stopped to stretch at a couple. I'm 99% positive I could not have run faster by pushing through. This is a case where knowing yourself is MUCH more important than what some formula says about what should or shouldn't be.
I am going to have to disagree with your point about the ideal IM run though - digging deep, yes. But the objective should be the fastest average pace for 26.2 miles. If you're really hurting before say mile 22-23 then I can pretty much guarantee you didn't pace appropriately to achieve the best average pace. You may have really spanked that first 20 miles but who cares when you give back 5min on the last 10k? How many people don't fade at the end? Not many - and that's my point. If you aren't running at least an even, if not slight negative, split then chances are you didn't execute that run properly to achieve the fastest average you were capable of. There is no award for who hurt the most. My marathon pace never really approaches the pain level...that's 5-10k race pace. I just get to the point where I'm out of gears and the legs won't turn over any faster. It's certainly not comfortable but I wouldn't compare it to gut-busting 5k pain.
If anyone cares to read my commentary on my run from IMCdA last year, it's in my race report.
Okay, sorry everyone for taking this off topic. I'm checking out of the thread - have a great weekend!
I agree rTSS has significance (otherwise, why am I bothering to download my runs into WKO?), but I don't think its nearly as accurate as TSS. Pace is still just an outcome of "power" that you generate and not a direct measure of the power itself. NGP certainly tries to account for change in elevations, but that's not the whole equation. Wind and road surface will have impacts as well (and frankly, give me a freakin hill over a 20mph head wind any day!- sorry I had to vent).
But let's assume for the moment that you can remove all the other variables from the equation so you can just look at the impact on total average pace that brisk walk break has on you metabolically. I suppose one could do a treadmill test with and without the walk breaks to see if a person could run a faster overall pace with the walk breaks at a lower heart rate? I realize HR isn't an exact or perfect metric either- but the real question here is if the breaks really do offer a physical benefit to allow you to run faster overall, or if it's more of a mental game.
I wonder if a similar test has been done somewhere? There are sub 3 hour marathoners using run/walk based on coaching advice from folks like Bobby McGee, so I gotta think some doctorate student has a study on it somewhere!
Keep in mind that wind doesn't nearly have the same impact on the run as it does on the bike. Still, I think we all get your point. I believe it's obvious to say that NGP has some holes as compared to NP but I think people need to spend some time reading some good threads on ST that occurred about 3 or so years ago. In those threads there was a discussion on the value of pacing your IM run by pace.
I think before we get into any testing we have to come to some agreement on the definition of a "walk break." 10 - 15 steps at an aid station is not my idea of a walk break.
I guess we're going to have to agree to disagree here. I ran a respectable marathon at IMCdA last year (3:14 - 25 OA fastest on the day) and walked at probably 22+ aid stations. Hell, I even stopped to stretch at a couple. I'm 99% positive I could not have run faster by pushing through. This is a case where knowing yourself is MUCH more important than what some formula says about what should or shouldn't be.
I am going to have to disagree with your point about the ideal IM run though - digging deep, yes. But the objective should be the fastest average pace for 26.2 miles. If you're really hurting before say mile 22-23 then I can pretty much guarantee you didn't pace appropriately to achieve the best average pace. You may have really spanked that first 20 miles but who cares when you give back 5min on the last 10k? How many people don't fade at the end? Not many - and that's my point. If you aren't running at least an even, if not slight negative, split then chances are you didn't execute that run properly to achieve the fastest average you were capable of. There is no award for who hurt the most. My marathon pace never really approaches the pain level...that's 5-10k race pace. I just get to the point where I'm out of gears and the legs won't turn over any faster. It's certainly not comfortable but I wouldn't compare it to gut-busting 5k pain.
If anyone cares to read my commentary on my run from IMCdA last year, it's in my race report.
Okay, sorry everyone for taking this off topic. I'm checking out of the thread - have a great weekend!
Couple of things:
1. I'd be very very careful about drawing any conclusion from a single event and making statements like "I'm 99% positive I could not run faster by pushing through." Honestly, if you haven't tried then you have absolutely no idea. This is IM. Speculating is meaningless (in this context).
2. I think you're oversimplifying my statement about an ideal IM run. Anyone who has read my stuff -- I've written quite a bit on this subject on EN and ST -- knows that I'm a huge advocate of even to neg splitting your run. So that just goes without saying. I thought it would be fairly obvious to people that you can't dig deep that freakin' hurts like there's no tomorrow for the entire run so my apologies if that wasn't clear to people. My point is that if it was so easy to execute your your IM run plan with no issues then you weren't running hard enough, imho. After 11 IMs I've had to watch and listen to people talk about their IM run. I'd say 95+% of them didn't go as plan (even the good ones) and probably 3 or 4% were just lying. None of mine have gone as planned and I'd probably say that 7 of my 11 IM runs were quite good.
Again, maybe things worked out perfectly for you but you would definitely by the exception. Anyway, you appeared my miss my final point which basically makes this whole conversation between us moot. Walking briskly for 10 - 15 steps is insignificant. It's not what I consider to be a "walk break."
Bear in mind that that not only changes in grade are used to calculate the physiologically relevant pace of NGP. As with NP in cycling, an exponential weighting step is utilized that is based on the relationship between intensity and lactate accumulation. So, not only is the NGP faster than the raw reported pace as a result of a positive grade, in some circumstances, an effort that has a component above the “threshold”will result in a more metabolically costly effort than indicated by the raw pace.
*****************
So, at what point do you plan to run above threshold during an IM paced effort? If you have a vDot of 55, using EN IM marathon guidance, you're running at a range of 08:28-07:54 min/mi (75-100% of LRP) while you have a threshold pace of 06:20.
I can accept rTSS as valid AND NGP as valid and say that NGP (and thus "run VI") isn't relevant to IM run pacing (unless of course I had the awesome run plan of running at 06:15 for 1200m and then walking 400m @ 12:55 for every mile of IM - ending up with a final pace of 07:56 min/mi, then I'd say that NGP might actually be relevant to show why I'm a moron with my run pacing.) But if I run @ 07:54 min/mi and walk for 30 seconds @ 16:00 min/mi, I'll end up with a per mile pace of 08:09 min/mi (or 78% of LRP, about middle of the EN chart) and at no time will I have ever gone faster than LRP, let alone MP or HMP and certainly not TP.
Bear in mind that that not only changes in grade are used to calculate the physiologically relevant pace of NGP. As with NP in cycling, an exponential weighting step is utilized that is based on the relationship between intensity and lactate accumulation. So, not only is the NGP faster than the raw reported pace as a result of a positive grade, in some circumstances, an effort that has a component above the “threshold”will result in a more metabolically costly effort than indicated by the raw pace.
*****************
So, at what point do you plan to run above threshold during an IM paced effort? If you have a vDot of 55, using EN IM marathon guidance, you're running at a range of 08:28-07:54 min/mi (75-100% of LRP) while you have a threshold pace of 06:20.
I can accept rTSS as valid AND NGP as valid and say that NGP (and thus "run VI") isn't relevant to IM run pacing (unless of course I had the awesome run plan of running at 06:15 for 1200m and then walking 400m @ 12:55 for every mile of IM - ending up with a final pace of 07:56 min/mi, then I'd say that NGP might actually be relevant to show why I'm a moron with my run pacing.) But if I run @ 07:54 min/mi and walk for 30 seconds @ 16:00 min/mi, I'll end up with a per mile pace of 08:09 min/mi (or 78% of LRP, about middle of the EN chart) and at no time will I have ever gone faster than LRP, let alone MP or HMP and certainly not TP.
I don't think you understand how the algorithm works. The exponential weighting factor is not only applied if your effort goes above threshold. The statement they make about an effort above "threshold" is just an example as efforts at that intensity become much more costly. Think about the bike, you still have to consider your bike VI for pacing purposes whether you spent any time at or above FTP or not.
I think people are making this more complicated than it is. It works very similarly to NP except it cannot account for the extra effort associated with things like wind or when terrain (eg grass) comes into play. If VI applies to cycling then it applies to running. You can't say that it applies to one and not the other UNLESS we have a discussion about the (uniquely individual) mental requirements associated with the IM run. That is the one big wildcard to this whole discussion. Like I stated before, the impact of walking (low power) or standing still (zero power) on "time efficiency" is much greater than it is on the bike. That's just a fact.
Interesting side note about mental issues: You can always train yourself to deal better with mental issues associated with the IM run. You can't change the math associated with optimal pacing.
Sorry, one last point because I think we got a little caught up in NGP but possibly ignored the fundamentals behind the lactate-exercise intensity (curve) relationship. Again, as intensity increases the metabolic cost increases in a non-linear fashion. It just gets much uglier above threshold. The curve is the same whether we are swimming, biking or running. The idea behind NGP (and NP) is to capture this true metabolic cost. Given this fact we always have to be aware that we don't get back (by walking) what we already put in so you're playing a losing battle from a time efficiency perspective. Whether the NGP algorithm is accurate or not, this logic still applies.
I wasn't so much trying say that run VI using NGP/AveP is the best or only way to determine proper run pacing. My focus was more about getting the sub-4hr IM runners to think about the benefit of walking periodically vs running the entire run from a time efficiency perspective.
Well here's an example you can chew on and tell me what it all means
55 minute run consisting of 5 min @ 10:00 min/mi, 1 mile @ 7:15, 1/2 mile @ 10:30, 1 mile @ 7:15, 1/4 mile @ 18:00 (i.e. walking), 1 mile @ 7:30, 1/4 mile @ 16:30 (i.e. walking), 1.5 mile @ 10:00. My threshold pace is 7:18 as entered in WKO+. The run was done on a treadmill so there is absolutely NO elevation gain playing into the calculation of NGP.
As you can see my Pace(avg) is 8:58 and my NGP is 8:52, giving me a whopping putative "run VI" of 1.011 for a workout that consisted of ~21 minutes above threshold running, ~25 minutes of LRP running, and ~8 minutes of walking. Even if you decide to manually calculate Pace(avg) using 55:55 and 5.984 miles, which actually gives you a Pace(avg) of ~9:20 (not 8:58), I still only calculate a putative "run VI" of 1.05 (560 seconds / 532 seconds) even with all that walking. It appears to me that whatever weight is given to more intensive running is incredibly minor in the algorithm for NGP compared to elevation. So how exactly am I misconstruing how the algorithm is working?
Again, as intensity increases the metabolic cost increases in a non-linear fashion. It just gets much uglier above threshold.
Right, for most individuals below LT, the lactate accumulation stays at ~2 mmol/L until LT is reached and then increases exponentially thereafter. Hardly an argument when discussing massively sub-threshold paces (since lactate will stay basically constant), as we do for the IM marathon, where even sub-4 triathletes are told to run somewhere between 75-100% of their LRP.
Again, as intensity increases the metabolic cost increases in a non-linear fashion. It just gets much uglier above threshold.
Right, for most individuals below LT, the lactate accumulation stays at ~2 mmol/L until LT is reached and then increases exponentially thereafter. Hardly an argument when discussing massively sub-threshold paces (since lactate will stay basically constant), as we do for the IM marathon, where even sub-4 triathletes are told to run somewhere between 75-100% of their LRP.
Are you somehow under the impression that it's any different on the bike? As a matter fact, I do the IM run at about 78 - 80% of threshold yet only 72 - 74% typically on the bike. So why is this discussion applicable on the bike yet not the run? Sure, absolute variability is inherently greater on the bike but it's a relative thing.
Look, I'll just respond to everything in this post...
How are you misunderstanding the algorithm? It's simple. You claimed it only accounted for changes in terrain. That's simply not true given that it applies an exponential weighting factor. Btw, given the flat terrain in your example above, you just proved my point too. But let me simplify things further: A pace that yields a time that is 10% faster than E pace, for example, does NOT yield the SAME 10% increase in metabolic cost. That's an important fact. As I stated before, I'm not sure what to make of NGP quite yet but a simple question might help. Do you feel that an NGP of 8:52 is reflective of the true physiological cost of that run you just did? Also, given the terrain is completely flat that VI might just suck. Again, it's a relative thing. We have no experience with run VIs so who's to know at the moment until we establish a baseline. Obviously a baseline for the run will not be the same as the baseline we've established for the bike. Remember, we had this problem with bike VIs early on. People didn't understand what a VI of 1.15 meant on a course like IMC or even IMCDA. As it turned out, it sucked big time.
Please reread my last post. I'm trying to focus the conversation on time efficiency and not so much NGP itself. However, it would be interesting to now start paying more attention to NGP because we might come to the conclusion that all of our run-related PMC charts are worthless. Either way, the fundamentals of my point still apply independent of the algorithm. The accuracy or validity of the algorithm is an entirely different issue.
Chris- Your right, the discussion is a bit sidetracked onto the accuracy of the actual calculations and accuracy of NGP and VI, but I think that's partially because of the subject of the thread.
So let's try to refocus back at the question you are asking - is there any true metabolic advantage to taking walk breaks during an IM run which will allow an individual to run a faster average pace, and if so, does that advantage overcome the time efficiency loss of taking the breaks. Does this reflect your question?
As you said, we probably need to get a clear definition of "walk breaks".
Chris- Your right, the discussion is a bit sidetracked onto the accuracy of the actual calculations and accuracy of NGP and VI, but I think that's partially because of the subject of the thread.
So let's try to refocus back at the question you are asking - is there any true metabolic advantage to taking walk breaks during an IM run which will allow an individual to run a faster average pace, and if so, does that advantage overcome the time efficiency loss of taking the breaks. Does this reflect your question?
As you said, we probably need to get a clear definition of "walk breaks".
Exactly!
Sorry, I know I'm probably belaboring the issue but I think it's an important consideration. Using a good example that applies to me, there's a huge difference between a 7:45 pace IM run and a 7:30 pace IM run -- both from a time perspective and from a metabolic/physiological perspective. 10 - 15 secs/mile doesn't look like much but my experience says that there's a significant difference between those two paces whether I'm running a marathon or even just doing a training run. I'd even argue that the difference between a good training run and injuring yourself could be just 15 secs/mile.
Btw, my fear (fear is actually the wrong word) is that we can never really answer the question with any certainty because the mental component is so significant or highly individual.
The reason to talk about this is in the context of "I'll try ANYTHING to improve my marathon time by X minutes" (X usually equals 5 or 10). I'm a bit of an evangelist, because I discovered about 5 years ago that my running pace - my speed when I am actually running - is FASTER when I walk for about 15-20 seconds every 8-10 minutes, than if I try to run every step, for runs of longer than about 1.5 hours. I don't really care why it works, just know that it does for me, to the point where I'm scared to drop the strategy, no matter what logic or mathematics might say.
BTW, I'm trying to improve my IM run time from 4:03 to 3:58 in 10 days, and I'll try ANYTHING - got any suggestions?
The reason to talk about this is in the context of "I'll try ANYTHING to improve my marathon time by X minutes" (X usually equals 5 or 10). I'm a bit of an evangelist, because I discovered about 5 years ago that my running pace - my speed when I am actually running - is FASTER when I walk for about 15-20 seconds every 8-10 minutes, than if I try to run every step, for runs of longer than about 1.5 hours. I don't really care why it works, just know that it does for me, to the point where I'm scared to drop the strategy, no matter what logic or mathematics might say.
BTW, I'm trying to improve my IM run time from 4:03 to 3:58 in 10 days, and I'll try ANYTHING - got any suggestions?
Again, sorry, I've been away from the forum for some time...
I hear what you're saying, Al. However, couldn't someone say they ride much faster when their variability is high than when it's low (even on a relatively flat course)? I've heard several people say that the "high VI" approach works best for them. Point being: Shouldn't we train our bodies to adjust to the best strategy? We know for a fact that the best strategy for the IM bike is to keep power relatively steady and all of those same principles of physics apply to running. Hence the whole reason why I started the thread.
Having said that, I've kinda abandoned pursuing anything else on this thread because I do believe there's too much of a mental requirement on the IM run. Sorry I couldn't provide you with any great advice in time for IMCDA but it appears it wasn't needed either. ;-)
Comments
I didn't misunderstand what you meant. I fully realize that in an ideal situation where you plan a run/walk strategy walking is the supposedly the "reward." However, it is also a fact that walking is ALWAYS the result of a mental breakdown too. My point is that what you think is a reward will quite often turn into mental breakdown because nobody out there really has their wits about them and if they do then they're not running hard enough, imho. As you said, it's a slippery slope. You, specifically, might be disciplined enough to pull it off but I'm not focusing on the exception, I'm focusing the rule. I truly believe that most people don't.
Look, let's be honest here, if your goal is to finish in the fastest possible time then there is no ideal IM run situation. An ideal IM run is digging so deep it freakin' hurts like there's no tomorrow. Think about it, how many people really don't fade that much on the IM run? Relatively speaking, it's extremely rare. IOW, I can count the number of people who really stick their plan on maybe 2 hands. Keep in mind that I'm also considering the people who lie to themselves after the race and say, "I stuck to my plan" (and then you look at their data).
Btw, if we're really talking/debating about walking briskly for 10 - 15 steps then let's move on. That's really not walking...
Thanks, Chris
Tony, Read this:
****************
Bear in mind that that not only changes in grade are used to calculate the physiologically relevant pace of NGP. As with NP in cycling, an exponential weighting step is utilized that is based on the relationship between intensity and lactate accumulation. So, not only is the NGP faster than the raw reported pace as a result of a positive grade, in some circumstances, an effort that has a component above the “threshold” will result in a more metabolically costly effort than indicated by the raw pace.
*****************
You don't need to theorize anything. It's pretty straightforward given that it uses and exponential weighting step. Clearly you're getting more than variability of terrain. Now we can debate the accuracy of what you get as far as metabolic cost is concerned but I'll continue to emphasis that if you believe rTSS has significance then you MUST believe that NGP has significance. You cannot question one without questioning the other.
Thanks, Chris
But let's assume for the moment that you can remove all the other variables from the equation so you can just look at the impact on total average pace that brisk walk break has on you metabolically. I suppose one could do a treadmill test with and without the walk breaks to see if a person could run a faster overall pace with the walk breaks at a lower heart rate? I realize HR isn't an exact or perfect metric either- but the real question here is if the breaks really do offer a physical benefit to allow you to run faster overall, or if it's more of a mental game.
I wonder if a similar test has been done somewhere? There are sub 3 hour marathoners using run/walk based on coaching advice from folks like Bobby McGee, so I gotta think some doctorate student has a study on it somewhere!
I guess we're going to have to agree to disagree here. I ran a respectable marathon at IMCdA last year (3:14 - 25 OA fastest on the day) and walked at probably 22+ aid stations. Hell, I even stopped to stretch at a couple. I'm 99% positive I could not have run faster by pushing through. This is a case where knowing yourself is MUCH more important than what some formula says about what should or shouldn't be.
I am going to have to disagree with your point about the ideal IM run though - digging deep, yes. But the objective should be the fastest average pace for 26.2 miles. If you're really hurting before say mile 22-23 then I can pretty much guarantee you didn't pace appropriately to achieve the best average pace. You may have really spanked that first 20 miles but who cares when you give back 5min on the last 10k? How many people don't fade at the end? Not many - and that's my point. If you aren't running at least an even, if not slight negative, split then chances are you didn't execute that run properly to achieve the fastest average you were capable of. There is no award for who hurt the most. My marathon pace never really approaches the pain level...that's 5-10k race pace. I just get to the point where I'm out of gears and the legs won't turn over any faster. It's certainly not comfortable but I wouldn't compare it to gut-busting 5k pain.
If anyone cares to read my commentary on my run from IMCdA last year, it's in my race report.
Okay, sorry everyone for taking this off topic. I'm checking out of the thread - have a great weekend!
Keep in mind that wind doesn't nearly have the same impact on the run as it does on the bike. Still, I think we all get your point. I believe it's obvious to say that NGP has some holes as compared to NP but I think people need to spend some time reading some good threads on ST that occurred about 3 or so years ago. In those threads there was a discussion on the value of pacing your IM run by pace.
I think before we get into any testing we have to come to some agreement on the definition of a "walk break." 10 - 15 steps at an aid station is not my idea of a walk break.
Thanks, Chris
Couple of things:
1. I'd be very very careful about drawing any conclusion from a single event and making statements like "I'm 99% positive I could not run faster by pushing through." Honestly, if you haven't tried then you have absolutely no idea. This is IM. Speculating is meaningless (in this context).
2. I think you're oversimplifying my statement about an ideal IM run. Anyone who has read my stuff -- I've written quite a bit on this subject on EN and ST -- knows that I'm a huge advocate of even to neg splitting your run. So that just goes without saying. I thought it would be fairly obvious to people that you can't dig deep that freakin' hurts like there's no tomorrow for the entire run so my apologies if that wasn't clear to people. My point is that if it was so easy to execute your your IM run plan with no issues then you weren't running hard enough, imho. After 11 IMs I've had to watch and listen to people talk about their IM run. I'd say 95+% of them didn't go as plan (even the good ones) and probably 3 or 4% were just lying. None of mine have gone as planned and I'd probably say that 7 of my 11 IM runs were quite good.
Again, maybe things worked out perfectly for you but you would definitely by the exception. Anyway, you appeared my miss my final point which basically makes this whole conversation between us moot. Walking briskly for 10 - 15 steps is insignificant. It's not what I consider to be a "walk break."
Thanks, Chris
So, at what point do you plan to run above threshold during an IM paced effort? If you have a vDot of 55, using EN IM marathon guidance, you're running at a range of 08:28-07:54 min/mi (75-100% of LRP) while you have a threshold pace of 06:20.
I can accept rTSS as valid AND NGP as valid and say that NGP (and thus "run VI") isn't relevant to IM run pacing (unless of course I had the awesome run plan of running at 06:15 for 1200m and then walking 400m @ 12:55 for every mile of IM - ending up with a final pace of 07:56 min/mi, then I'd say that NGP might actually be relevant to show why I'm a moron with my run pacing.) But if I run @ 07:54 min/mi and walk for 30 seconds @ 16:00 min/mi, I'll end up with a per mile pace of 08:09 min/mi (or 78% of LRP, about middle of the EN chart) and at no time will I have ever gone faster than LRP, let alone MP or HMP and certainly not TP.
I don't think you understand how the algorithm works. The exponential weighting factor is not only applied if your effort goes above threshold. The statement they make about an effort above "threshold" is just an example as efforts at that intensity become much more costly. Think about the bike, you still have to consider your bike VI for pacing purposes whether you spent any time at or above FTP or not.
I think people are making this more complicated than it is. It works very similarly to NP except it cannot account for the extra effort associated with things like wind or when terrain (eg grass) comes into play. If VI applies to cycling then it applies to running. You can't say that it applies to one and not the other UNLESS we have a discussion about the (uniquely individual) mental requirements associated with the IM run. That is the one big wildcard to this whole discussion. Like I stated before, the impact of walking (low power) or standing still (zero power) on "time efficiency" is much greater than it is on the bike. That's just a fact.
Interesting side note about mental issues: You can always train yourself to deal better with mental issues associated with the IM run. You can't change the math associated with optimal pacing.
Thanks, Chris
I wasn't so much trying say that run VI using NGP/AveP is the best or only way to determine proper run pacing. My focus was more about getting the sub-4hr IM runners to think about the benefit of walking periodically vs running the entire run from a time efficiency perspective.
Thanks, Chris
Well here's an example you can chew on and tell me what it all means
55 minute run consisting of 5 min @ 10:00 min/mi, 1 mile @ 7:15, 1/2 mile @ 10:30, 1 mile @ 7:15, 1/4 mile @ 18:00 (i.e. walking), 1 mile @ 7:30, 1/4 mile @ 16:30 (i.e. walking), 1.5 mile @ 10:00. My threshold pace is 7:18 as entered in WKO+. The run was done on a treadmill so there is absolutely NO elevation gain playing into the calculation of NGP.
As you can see my Pace(avg) is 8:58 and my NGP is 8:52, giving me a whopping putative "run VI" of 1.011 for a workout that consisted of ~21 minutes above threshold running, ~25 minutes of LRP running, and ~8 minutes of walking. Even if you decide to manually calculate Pace(avg) using 55:55 and 5.984 miles, which actually gives you a Pace(avg) of ~9:20 (not 8:58), I still only calculate a putative "run VI" of 1.05 (560 seconds / 532 seconds) even with all that walking. It appears to me that whatever weight is given to more intensive running is incredibly minor in the algorithm for NGP compared to elevation. So how exactly am I misconstruing how the algorithm is working?
Right, for most individuals below LT, the lactate accumulation stays at ~2 mmol/L until LT is reached and then increases exponentially thereafter. Hardly an argument when discussing massively sub-threshold paces (since lactate will stay basically constant), as we do for the IM marathon, where even sub-4 triathletes are told to run somewhere between 75-100% of their LRP.
Are you somehow under the impression that it's any different on the bike? As a matter fact, I do the IM run at about 78 - 80% of threshold yet only 72 - 74% typically on the bike. So why is this discussion applicable on the bike yet not the run? Sure, absolute variability is inherently greater on the bike but it's a relative thing.
Look, I'll just respond to everything in this post...
How are you misunderstanding the algorithm? It's simple. You claimed it only accounted for changes in terrain. That's simply not true given that it applies an exponential weighting factor. Btw, given the flat terrain in your example above, you just proved my point too. But let me simplify things further: A pace that yields a time that is 10% faster than E pace, for example, does NOT yield the SAME 10% increase in metabolic cost. That's an important fact. As I stated before, I'm not sure what to make of NGP quite yet but a simple question might help. Do you feel that an NGP of 8:52 is reflective of the true physiological cost of that run you just did? Also, given the terrain is completely flat that VI might just suck. Again, it's a relative thing. We have no experience with run VIs so who's to know at the moment until we establish a baseline. Obviously a baseline for the run will not be the same as the baseline we've established for the bike. Remember, we had this problem with bike VIs early on. People didn't understand what a VI of 1.15 meant on a course like IMC or even IMCDA. As it turned out, it sucked big time.
Please reread my last post. I'm trying to focus the conversation on time efficiency and not so much NGP itself. However, it would be interesting to now start paying more attention to NGP because we might come to the conclusion that all of our run-related PMC charts are worthless. Either way, the fundamentals of my point still apply independent of the algorithm. The accuracy or validity of the algorithm is an entirely different issue.
Thanks, Chris
Chris- Your right, the discussion is a bit sidetracked onto the accuracy of the actual calculations and accuracy of NGP and VI, but I think that's partially because of the subject of the thread.
So let's try to refocus back at the question you are asking - is there any true metabolic advantage to taking walk breaks during an IM run which will allow an individual to run a faster average pace, and if so, does that advantage overcome the time efficiency loss of taking the breaks. Does this reflect your question?
As you said, we probably need to get a clear definition of "walk breaks".
Exactly!
Sorry, I know I'm probably belaboring the issue but I think it's an important consideration. Using a good example that applies to me, there's a huge difference between a 7:45 pace IM run and a 7:30 pace IM run -- both from a time perspective and from a metabolic/physiological perspective. 10 - 15 secs/mile doesn't look like much but my experience says that there's a significant difference between those two paces whether I'm running a marathon or even just doing a training run. I'd even argue that the difference between a good training run and injuring yourself could be just 15 secs/mile.
Btw, my fear (fear is actually the wrong word) is that we can never really answer the question with any certainty because the mental component is so significant or highly individual.
Thanks, Chris
The reason to talk about this is in the context of "I'll try ANYTHING to improve my marathon time by X minutes" (X usually equals 5 or 10). I'm a bit of an evangelist, because I discovered about 5 years ago that my running pace - my speed when I am actually running - is FASTER when I walk for about 15-20 seconds every 8-10 minutes, than if I try to run every step, for runs of longer than about 1.5 hours. I don't really care why it works, just know that it does for me, to the point where I'm scared to drop the strategy, no matter what logic or mathematics might say.
BTW, I'm trying to improve my IM run time from 4:03 to 3:58 in 10 days, and I'll try ANYTHING - got any suggestions?
Again, sorry, I've been away from the forum for some time...
I hear what you're saying, Al. However, couldn't someone say they ride much faster when their variability is high than when it's low (even on a relatively flat course)? I've heard several people say that the "high VI" approach works best for them. Point being: Shouldn't we train our bodies to adjust to the best strategy? We know for a fact that the best strategy for the IM bike is to keep power relatively steady and all of those same principles of physics apply to running. Hence the whole reason why I started the thread.
Having said that, I've kinda abandoned pursuing anything else on this thread because I do believe there's too much of a mental requirement on the IM run. Sorry I couldn't provide you with any great advice in time for IMCDA but it appears it wasn't needed either. ;-)
Thanks, Chris