Which workout is more aerobic, and which is more anaerobic: 12x400 45 sec rest, or 12x400 3 min rest?

If the 400m's are run at the same pace, the one with the less rest will be more aerobic.

Let's say you run the 400m's in 60s each. At the start of the first rep, your VO2 will increase throughout the entire 60s duration, but never reach the VO2 requirement for the 60s 400m (call that 100%)...it might get to 65-70% of the required VO2 if your O2 kinetics are really fast.

Given a 45s rest, your VO2 will begin to go down slightly such that at the start of the next rep, your VO2 may now be somewhere around 50%. Given similar O2 kinetics, your VO2 should increase near the same rate such that at the end of the 2nd rep, you might be at 90%. Eventually, after 3 or 4 reps, your VO2 will reach the 100% VO2 required.

Given a 3 min rest, your VO2 will go down well below the 50% VO2 during the 45s rest (let's say 30%). So the second rep starts at 30% VO2 and might end at 70%. Another 3 min rest allows your VO2 to go down further once again (maybe to 40%) and get to 80% at the end of the 3rd rep and so on.

Remember, anything below the 100% VO2 has to be sustained by non-oxidative metabolism and you will always start the rep with a lower VO2 the longer rest you take. This energy will not be supplied aerobically, so the 45s rest workout will be more aerobic.

jT

2 questions:

1) regarding the post you just made, I didn't quite understand what you were talking about when you mentioned (in the second paragraph) "your VO2 will increase throughout the entire 60s duration, but never reach the VO2 requirement for the 60s 400m (call that 100%)...". I don't get what you mean by "VO2 requirement for the 60s 400m". Do you mean the VO2 requirement to run the entire thing 100% aerobic? (which I understand isn't possible, both aerobic and anaerobic metabolism are always present). Because clearly there WAS enough energy to run it in 60s if you were able to finish it in 60s... So just elaborate on what you meant by "VO2 requirement for the 60s 400m" in para. 2. I think what you are talking about is also touched upon in the first sentence of your last paragraph ("Remember, anything below the 100% VO2..."). If you could clear that up, I think I would understand the entirety of your post. VO2 is just the volume of O2 present (in the blood, in the legs, somewhere) right?

2) If you wanted to give an athlete some strong ANAEROBIC stimulus (to improve their ability to make energy anaerobically), what kind of workout would you give?

Thank you very, very much. My 2nd question is something I've been thinking about for some time now, and you're the person I would most love to have answer it. I have an idea of what would be a good session to improve anaerobic energy production, but an answer from you would end any doubts.

Thank you very much.

Great questions:

1. Yes. The "VO2 required" is the energy (oxygen) required to run the 400m 100% aerobically. This VO2 is the oxygen you're consuming to provide your body with energy to run that pace.

For most well-trained athletes, it takes about 90-120s for the VO2 to reach the VO2 required. This of course, only applies to intensities below the anaerobic threshold. Above this, you will always have a slow-component of oxygen uptake, where your VO2 will keep climbing until you reach VO2max. But, for simplicity, this of the 400m VO2 requirement as "100% VO2max". So, you start the workout at probably ~5% VO2max and might reach 65 or 70% VO2max in 60s (I'm over-simplying it a bit, but the point is it will be BELOW 100% VO2max).

So, remember, any energy that is below the 100% O2 required has to come from somewhere other than oxidative metabolism. This is where the non-aerobic (anaerobic) energy systems provid this energy. Almost think of it like this: You start running at VO2max pace but you're obviously not IMMEDIATELY at VO2max. That energy needs to be provided non-aerobically.

So, by giving yourself MORE rest, you're allowing your VO2 to come down closer to resting VO2 relative to the shorter rest. By starting at a lower VO2 for the next rep, there is a larger anaerobic contribution that has to supplement the energy not supplied by the VO2 alone.

To make this workout the most aerobic you can, you could simply just run 12x400m @ 60s with NO rest. That way, your VO2 will start climbing, after 2-3 minutes probably reach VO2max and you'd just have to be able to sustain VO2max pace for as long as you could. Most people can do this for between 3-6 minutes.

To answer your second question, this can be answered for the same principles. For a strong anaerobic stimulus, I would have someone run at a pace well-above VO2max for a short enough duration that their VO2 would never approach max. Thus, almost all the energy has to be supplied anaerobically.

For example, a 30s 200m rep is now still 100% of VO2max but lasts half the time so given the same O2 kinetic response as my 60s 400m example before, my VO2 at the end of the rep is going to be half of my 60s 400m VO2 - call it 32-35% VO2max - because the rep is half the time, so my VO2 has half the time to climb. If I give the athlete a lot of rest such that the VO2 comes back down to near resting again (maybe 3-5 mins), and do the same 30s 200m, my VO2 will once again only be 32-35% by the end of the rep (for the pundits out there, it will be slightly higher than this because of the altered VO2 kinetics, but for simplicity, call it 32-35%).

The point is in this situation, your VO2 will never get to what is it during the 400m workout but the energy requirement is the exact same: "100% VO2max". So, the lower the VO2, the larger your anaerobic energy contribution.

This is a great example to highlight how modifying the work length, the rest length and the number of reps can seriously alter the physiological demands (and later the physiologial BENEFITS) of the same workout.

Same pace, same amount of work but 2 very different physiological stimuli.

12x400m @60s pace with 45s rest - a good aerobic stimulus

24x200m @30s pace with 3 min rest - a good anaerobic stimulus

I hope that helps and makes some sense.

jT

Great information.

Just want to clarify one thing: Based on what is said, in order to train for anaerobic capability, we can simply train at VO2MAX pace and keep the run shorter and rest longer? I have always thought that you need to run at a faster pace and keep it as long to almost reach VO2MAX for each repeat?

pally wrote:

Great information.

Just want to clarify one thing: Based on what is said, in order to train for anaerobic capability, we can simply train at VO2MAX pace and keep the run shorter and rest longer? I have always thought that you need to run at a faster pace and keep it as long to almost reach VO2MAX for each repeat?

Yes, you're correct. I just used the above example to highlight which one is more aerobic relative to the other. That doesn't say anything about the latter workout being more "anaerobic". To show this, the same 12x400m workout is LESS aerobic than 15x400m at the same pace. It is also less aerobic than 6x800m at the same pace, all else being equal.

The capacity of the anaerobic system is about 90-120s, so any reps shorter than this will stimulate the anaerobic energy system. The easiest answer to your question to "train anaerobic capcity" is to constantly stimulate it by doing anerobic intervals shorter than 90s, and doing them FAST.

A typical anaerobic workout might be 3-4x400-600m with lots of rest between. Recent evidence also suggests 5x30s full-out with 4 mins rest is also very effective. But as with manipulating workouts to make them more/less aerobic, you can manipulate any number of them to make them more/less anaerobic. And the easiest way to do that is to try to accomplish as much work as quickly as possible. In a lab setting, we might say "how quickly can you do 30000 J of work?" From a running sense, "how quickly can you complete 2 miles worth of running?"

You could just run 2 miles @ 4:30 pace

You could do 2x1 mile @ 4:10 pace with 3-5 mins rest

You could do 32x100m @ 12s/100m pace.

Although all the workouts are the same amount of WORK, the first workout is done at a relatively lower intensity, so it would be the most aerobic. The last workout, being done at 3:12 mile pace, is clearly a much greater intensity, and thus more anaerobic.

jT

{For most well-trained athletes, it takes about 90-120s for the VO2 to reach the VO2 required. This of course, only applies to intensities below the anaerobic threshold. Above this, you will always have a slow-component of oxygen uptake,...}

Questions:

So the anaerobic threshold is the place where anything faster would have the VO2 required exceed the athlete's VO2 max?

At intensities below the anaerobic threshold, once VO2 required is reached, is energy production 100% aerobic? Perhaps, only negligible anaerobic contribution?

What did you mean by "slow-component of oxygen uptake"?

Thanks so much.

Anaerobic threshold (AnT)is the highest intensity you can sustain while still sustaining a steady-state of oxygen uptake. Let's say your AnT is 10 mph. If you run at any intensity below 10 mph, your VO2 will level off at some % of VO2max. AnT is typically around 80-90% of VO2max for well-trained runners. If you run slightly faster than 10 mph, your VO2 will NOT reach a steady-state level. It will slowly continue to creep up and continues to creep up until you hit VO2max. If you're 102% above AnT, this will take a long time, and you may stop even before hitting VO2max. If you're 120% of AnT, it will probably take you less than 10 minutes to get to VO2max. This "creeping up" of VO2 is what is referred to as the "slow component of oxygen uptake".

To put it simply, yes. There is always SOME anaerobic energy production going on due to the oxygen deficit at the start of exercise (the time it takes for VO2 to reach that steady-state), but the energy can be supplied 100% aerobically.

As I mentionned above, the slow component is that extra VO2 you get when you're above AnT, over and above the VO2 required. So, if your VO2 requirement at AnT at 10 mph is 3 L/min and you run 10.0 mph, your VO2 should remain at 3 L/min. If you run faster than this, your VO2 will never stay at 3 L/min...it will constantly drift up until you hit VO2max or other fatigue-inducing factors cause you to stop.

jT

"If you run slightly faster than 10 mph[AnT], your VO2 will NOT reach a steady-state level. It will slowly continue to creep up and continues to creep up until you hit VO2max." Does it creep beyond VO2 requirement? It would have to, unless VO2 requirement was VO2 max, but the VO2 requirement at AnT ISNT VO2 max, if I'm not mistaken... So, why does it creep beyond VO2 requirement?

If you feel like answering them: (I have to milk this opportunity! Haha):

Is there an "aerobic threshold"? What is it? Maybe it's the same as the "anaerobic threshold". You don't have to go super in depth, a sentence-long definition would be fine.

A more general, and perhaps heavier, question:

When I think back to your book (I read it when I was first getting into running), you seemed like more of a low volume, higher quality kind of guy. I remember you showing a chart which basically stated that the benefits of more mpw begin to level off, the more mpw you're talking about (for instance, the benefits of going from 100 to 120 are lesser than from 80 to 100). Would you call yourself a low miles guy (as far as what you believe is best)? If so, what is your stance based off (from a physiological standpoint)? Is it true that the aerobic system can be adequately stimulated without big miles, but instead "special" (perhaps VO2 max type) workouts? How much of your low volume stance is based off of the fear of injury/illness? In your opinion, what are the physiological benefits of big miles?

I'm simply curious as to why- assuming that you are- you're a low volume guy. Hopefully you can answer from more of a physiological perspective; I already understand the more general, non-physiological reasoning behind low volume. And I'm not insinuating that you think everyone should be doing 30 mpw, but I do know that you're not a big miles-fanatic.

To be able to question Jack Daniels on the physiological ins and outs of low miles vs big miles is simply awesome.

A more general, and perhaps heavier, question:

When I think back to your book (I read it when I was first getting into running), you seemed like more of a low volume, higher quality kind of guy. I remember you showing a chart which basically stated that the benefits of more mpw begin to level off, the more mpw you're talking about (for instance, the benefits of going from 100 to 120 are lesser than from 80 to 100). Would you call yourself a low miles guy (as far as what you believe is best)? If so, what is your stance based off (from a physiological standpoint)? Is it true that the aerobic system can be adequately stimulated without big miles, but instead "special" (perhaps VO2 max type) workouts? How much of your low volume stance is based off of the fear of injury/illness? In your opinion, what are the physiological benefits of big miles?

I'm simply curious as to why- assuming that you are- you're a low volume guy. Hopefully you can answer from more of a physiological perspective; I already understand the more general, non-physiological reasoning behind low volume. And I'm not insinuating that you think everyone should be doing 30 mpw, but I do know that you're not a big miles-fanatic.

To be able to question Jack Daniels on the physiological ins and outs of low miles vs big miles is simply awesome.[/quote]

Now there's a good question. I'd love to see it answered. I hadn't even realized that this was Jack Daniels.

jtupper-ware, your information on the slow component of oxygen uptake is helpful, but you are overthinking the aerobic/anaerobic stimulus, and underestimating the neural stimulus of each workout. Running is much more about developing motor control skills in the long term than metabolic developments. Speed and endurance are fundamentally dependent on nervous system control to deliver energy as efficiently as possible.

Obviously as your name jtupper-ware suggests, you are never going to think outside your tunnel vision of oxygen uptake, but really you should if you want to really get to grips with training methodology. Jack Daniels can't or won't address these issues and for that reason his vision is extremeley lacking in real substance, however much it may interest those who are easily impressionable.

Also you should learn a bit more about energy systems. Glycogenolysis and glycolysis are always supplying energy anaerobically no matter how slow the pace and regardless of the oxygen deficit. Glycogenolysis provides 6 times as much ATP as glycolysis and the two systems are always used whenever glycogen and glucose are used.

12x400 with 45 seconds rest will be run at about 3000m pace maybe slightly faster.

3 minutes is too long for 12x400 at mile pace/1500 pace, but obviously with longer recoveries a faster pace will be more anaerobic.

But as I alluded in my previous post, trying to think about training in terms of aerobic/anaerobic is just the wrong way to go about training. The right way is just to think about it in terms of practicing race pace, then you won't overthink it, you will just do it and be a better runner for it.

Please don't take my discussion on oxygen uptake as me disregarding the neural (or any other) component of training. I'm simply answering the question "which workout is more aerobic". Not necessarily "which workout will make me faster over 'X' meters". If you must know, I am very much a "neural guy" as I think much of what we know about exercise physiology can be explained by progressive recruitment of motor units. So no, I'm not disregarding the neural component at all simply trying to answer the question(s) that are asked. If you want to discuss neural stimuli, that's a topic for another thread.

For those who might be "easily impressionable", I can understand that argument completely. Nothing in exercise physiology is "black and white", as you'll probably notice in most of my replies, that I'm trying to offer the simple side of the story, without going into a long-winded response on, for example, definitions of the anaerobic threshold or the slow-component of oxygen uptake.

Lastly, as it relates to energy systems, if you refer to my post above, I did in fact mention that there is always some non-aerobic energy being provided, even at rest. This is one of many reasons why your blood lactate at rest is never 0 mM. Could a given intensity be sustained nearly 100% aerobically? Absolutely it can! If it couldn't then what is the point of measuring VO2???

long dong silver wrote:

"If you run slightly faster than 10 mph[AnT], your VO2 will NOT reach a steady-state level. It will slowly continue to creep up and continues to creep up until you hit VO2max." Does it creep beyond VO2 requirement? It would have to, unless VO2 requirement was VO2 max, but the VO2 requirement at AnT ISNT VO2 max, if I'm not mistaken... So, why does it creep beyond VO2 requirement?

There are 2 generally accepted theories for the VO2 slow component at intensities above the AnT.

1) At intensities above AnT, you will begin to fatigue slow motor units. In order to sustain that pace, you will need to recruit more and more motor units as the already recruited motor units begin to fatigue. These additional motor units will be progressively more of the Type II (fast twitch) motor units. These newly-recruited motor units require energy, and as such, the VO2 begins to rise.

One caveat to that is this: if your muscles contract at the same velocity, for example if your stride frequency doesn't change, then these newly-recruited motor units are contracting at a velocity that is below their optimal efficiency. As a result, to sustain the same workload with a lower efficiency means VO2 has to increase. You can minimize, or maybe even eliminate the slow component if you could get your muscles to contract at a velocity that is now the "new optimal" velocity of shortening. In human muscle, this shortening velocity is about 0.1 fiber lengths/second for slow twitch fibers and about 0.2 Fl/s for fast fibers.

2) Receent evidence from Grassi and Rossiter's labs have shown that even if you stimulate all the motor units right from the start of exercise, then you can eliminate the "progressive recruitment" problem as I described above. These authors have shown that when maximally stimulated, you still get a slow component, suggesting the VO2 demand for that given maximal workload also increases.

So, my opinion is it's probably a combination of both 1 and 2.

jT

Well thaks for not taking my post too personally, you see I do get frustrated that exercize physiology is misrepresented by tunnel visionary scientists who don't see the big picture and don't work with information from other fields of research.

I disagree with your comment about 100% aerobic intensity though, this is impossible, as it would require zero carbohydrate metabolism which is not metabolically possible, and is the reason why starving people have to convert muscle tissue into glucose/glycogen.

One contentious issue which researchers are afraid to say out loud is that all stored carbohydrate in involved in lactate producion. There is no pyruvate to mitochondria metabolic pathway without converion to lactate first.

J.O. wrote:

12x400 with 45 seconds rest will be run at about 3000m pace maybe slightly faster.

To think that 12X400m 3000m pace or may be slightly faster with 45seconds recovery it´s to ignore and misunderstand the motor units precisely, something you say it´s important to consider.

To run this workout at 12X400m 3000m pace all depends if the runner is a FT or a ST runner and it depends what´s the runner best distance event.

I followed very closely one 3:30 1500m pb, olympic bronze that is the portuguese Rui Silva. You can trust me that IF THE REST IS JUST 45secs he can´t run 12X400m at 60secs intervals that is 7:30 3000m slighly faster than his 3000m pb. Besides when he did fast 400s intervals he can´t stand shorter recovery than 60s-70secs stand.

I imagine that you your experience with the kind of Rui 1:44/3:30/7:36 of world class is limited. Therefore you suggest of 12X400m at 3000m pace, i imagine that the runners that you have seen doing might be they are poor runners, weak performers, or they don´t.

[quote]jtupper-ware wrote:

If you want to discuss neural stimuli, that's a topic for another thread.[quote]

This may very well be the last intensive physiology/training thread on LR, ever. Okay, maybe not the last, but close to. This place is overrun with more casual topics now... So by all means discuss neural stimuli here. We already have Cabral (who I thought had left LR) and Daniels (who I thought had left LR) here, so if there ever was a better time...

FT ST dogma Antonio?

Rui Silva's fast twitch fibers are mostly oxidative.

For the session, start at slightly slower than race pace and gradually speed up.

You know, the way Rui Silva liked to train?

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The oxygen cost depends very much on muscle tone, when the tone is optimal then the cost of oxygen is much lower, if this can be sustained, performance is greatly enhanced.

The problem of heat production can make the workload progressively harder, which in turn increases heat production and so on.