vo2max question serious answers only

Something i've wondered about this type of scenario...

Is it possible to have a "hummer" type of engine ' i.e. high Vo2 but a "yugo" body type i.e weak muscular structure. Therefore, you won't be able to reach your max potential because your muscles can't withstand the intensity your heart and lungs can output so you get injured. On the opposite end, there are people with a 4-cylinder engine meaning a low VO2 but a strong body type like a hummer and also not be able to reach potential because they can't push their muscles to their capacity.

It just seems like the people i know who have higher VO2s to get injured whereas people with lower VO2s are not as fast but rather than getting hurt, the tend to overtrain.

is there anything legit about this theory?

To a couple questions: When running pretty hard yuo actually move about 2/3 of your vital capacity with each breath. If you have a 5-liter VC and another liter of residual volume, 2/3 of the 5 is 3.33 liters which is still over half of your (6-liter) total lung volume, per breath. Healthy people aren't limited by how much air they ventilate. You usually get as much oxygen into the blood passing through the lungs as you can get> For example, taking a stress test using a rather restrictive breathing valve will reduce the amount of air you ventilate per minute but may not lower VO2 any -- you will just use more of the oxygen you breathe in. The discomfort you experience when you feel you need more air is a build up of Carbon dioxide, not a lack of oxygen.

Jim: Increasing upper body mass will probably reduce relative VO2 (both max and submax -- one not good the other good, because we are just talking about math here). Remember, a lower relative submax VO2 says better economy, in fact overweight people often look more economical than are lean people because you are dividing absolute max by body mass. Of course this is the reason vVO2max is so important (as Tom Schwartz has pointed out). If increased strength in upper body improves running mechanics then you may be more economical. Often orthotics bring on better economy (through better mechanics) even though they increase the weight of the shoes (which tends to negatively affect economy)

I often wonder about economy. Substrate utilization may indeed be a part of sub-L.T. economy. That is, using more fat or more CHO can affect economy. Fat requires more O2 to burn than Carbohydrate.

It seems counter-intuitive that more fat is being used at speeds below lactate threshold when an athlete tested reveals a lower oxygen cost (economy) after training. The exact opposite should be occuring: more carbs being burned. More carbs = less oxygen used. More fat = more oxygen used.

So, if less oxygen is being consumed after a training period, then is there another reason for the improved economy? Are more carbs being burned? Are there neural-mechanical improvements that reduce oxygen cost? Tom

start cycling or any other endurance sport

I'm thinking a lot is related to minimizing the amount of muscle used while running -- eliminating unnecessary movement or stabilizing muscle. I've seen no indication of a change in substrate with better fitness. It's important to recognize the effect test-day weight has on economy. When we ran marathoners for 20 miles on a TM, we tested economy every 30 minutes and then got a quick body weight (with a 15-second pause from running). We found a steady increase in VO2 per kg (but only due to weight loss), but identical absolute VO2 throughout the run. Obviously a per kg value will go up (as would VO2max per kg). It is important to look at absolute VO2 rahter than relative VO2 when looking at the same subject at different weights that are the relsut of fluid loss.

JT,

It seems to me that economy improvements slow as a runners improves over the months and years. Have you seen any indications that economy could improve rapidly in experienced runners with certain types of training? I understand, of course, that economy has a wide range including very slow to very fast, so improvements with training might be specific and limited to paces close to those trained at in practice. TS

slow day...

1) (this for jtupper) why tell distance runners to do 400m repeats at 1500m pace with 5 mins recovery to improve economy when distance runners are often more economical at distance paces than 1500m runners?

2) any thoughts on the published science saying that less flexible distance runners are more economical?

3) what possible mechanism would make those with low VO2max "compensate" with good economy, and those with high VO2max struggle with poor(er) economy? It's like somebody somewhere wants competition between the two to be "fair" somehow. which is ridiculous.

I've seen several % improvement in economy in only a few months, but that was a guy who was out of shape during the early test and getting back into it in the later test. So many factors to control for when trying to evaluate improvements in economy, because the shoes you wear for testing can affect results, as can current weight, etc. Want to look good in economy test? just show up with a couple extra pounds of fluid in your body.

Regarding the less flexible being more economical, that doesn't jive too well with older people getting less economical, but in this case it could also be a matter of what is being flexible or less flexible.

Why those with poorer economy tend ot have higher max, good question. It needs good controlled study. Maybe the types of muscle fibers that have the cahracteristics for good economy are limited in their ability for high aerobic power -- needs looking at.

Why run faster than race pace (if you are a long-distance runner)to try to improve economy? So far I see the longer-distance specialists being more economical at slower than their race pace, paces that they don't compete at, and if the shorter-distance racers are more economical as the velocity gets faster, it would seem these longer-distance runners could also benefit from improving economy at more rapid run velocities. Of course the proof is in how your training influences your racing. Whatever training makes you race better is the right training.

Jtupper,

Thanks for the replies. I thought I had read you saying somewhere that marathon runners were more economical at marathon pace than 1500m runners at marathon pace, (although 1500m runners became more economical as they got closer to their race pace, and marathon runners less so as the pace became faster than marathon pace). Guess it was some other guy. Will pigeon-hole it to check where I read it.

Odd, given your many years of interest in economy (have probably read all you published) that you haven't heard of the possible relationship with flexibility. These might be of interest on a slow day...

AM Jones. Running economy is negatively related to sit-and-reach test performance in international-standard distance runners. Int J Sports Med. 2002 Jan;23(1):40-3

"These results suggest that the least flexible runners are also the most economical. It is possible that stiffer musculotendinous structures reduce the aerobic demand of submaximal running by facilitating a greater elastic energy return during the shortening phase of the stretch-shortening cycle."

Craib MW, Mitchell VA, Fields KB, Cooper TR, Hopewell R, Morgan DW. The association between flexibility and running economy in sub-elite male distance runners. Med Sci Sports Exerc. 1996 Jun;28(6):737-43

"Although speculative, these results suggest that inflexibility in certain areas of the musculoskeletal system may enhance running economy in sub-elite male runners by increasing storage and return of elastic energy and minimizing the need for muscle-stabilizing activity."

Again, thanks for taking time to reply.

In relation to the two seperate methods used to describe Vo2max (absolute [L.min] & relative [ml.kg.min]), an area that is often missed is 'scaling'. The major problem with the relative value is that overly heavy or overly light subjects have mis-represented relative VO2max values. To get around this problem you scale your VO2max value to your body size (to the power of 2/3).

In relation to a seperate reply...

It is documented that inflexibility benifits running economy due to the biomechanics of the event. inflexible joints / muscles will provide a far more rigid structure - and therefore less energy is lost in the gait cycle

Hope this helps

On the flexibility issue. Isn't basic speed at least a little bit related to range of motion? If this is so, inflexibility might reduce a persons basic speed and possibly limiting stride length. Then again, good basic speed correlates somewhat to higher racing speeds across all distances, if endurance is held a constant.

Which is better for a distance runner, economy through basic speed or through inflexibility?

What are some good workouts to improve running economy for a 10k-Mar type runner?

I've always liked 20x400 with 1min rest@3-5k speed for improving a range of running factors. Fast enough to improve power/strength, fast enough to require good biomechanics(mechanical economy), long enough/volumous enough to improve metabolic economy/fitness.

The idea of training the respiratory muscles to improve performance has been around for a while. A researcher in Europe (his name escapes me) has published several papers showing an improvement benefit, but when others have tried to replicate the studies, the results have not supported the European's findings.

Jim Williams is a US researcher who has been looking at this and not found any performance enhancement in several studies using collegiate XC and track athletes. You can find abstracts with a PubMed search.

One potential area where improvement could come is that if the respiratory muscles become more "fit", they would take less O2 at high end exercise which of course would free up more O2 for muscles that are providing propulsion. In the studies published, such findings have been found, but there is no concurrent performance improvement.

As noted elsewhere, for a healthy person, ventilation is not a limiting factor in exercise although at very high volume flows Dave Martin has shown some disturbances in otherwise healthy individuals.

Tschwartz wrote:

JT,

It seems to me that economy improvements slow as a runners improves over the months and years. Have you seen any indications that economy could improve rapidly in experienced runners with certain types of training? I understand, of course, that economy has a wide range including very slow to very fast, so improvements with training might be specific and limited to paces close to those trained at in practice. TS

It would make sense that improvement slows as one gets better. You are approaching the ceiling of ability.

There is some literature on explosive weight training improving running economy although little of it has been done on elite athletes. It could be that the muscles are developing more power (force x distance/time) through reducing ground contact time.

I have theorized based on some cycling studies that years of aerobic training make a difference in economy as the same of the slow oxidative glycolytic (SOG) muscle fibers become more aerobic and that the shift aids in running economy. Ed Coyle and Andy Coggan have published papers on cyclists showing how years of training related to economy. I am not familiar with anything similar in running (I really should check).

Just a note: This is one of the better threads on this site since the time I have been here. Thanks to everyone for their adult behavior here!