The '20 minute tempo run'

"LT pace is highly efficient at stimulating a shift in the metabolic mix towards glycolysis at a given pace. The benefits of which should be obvious."

This is the part I'm wondering if you are sure about.

SlowFatMaster wrote:

"LT pace is highly efficient at stimulating a shift in the metabolic mix towards glycolysis at a given pace. The benefits of which should be obvious."

This is the part I'm wondering if you are sure about.

Pretty sure. Correct me if I'm wrong. I'm basing this on my own reading and research. The literature I've read says that A) Skeletal muscle is highly adaptable to shifting energy sources to supply demanded ATP, and B) Exercise at the point where the byproducts of anaerobic respiration begin to accumulate in the cells provides the needed stimulus.

If anyone wants some light reading about lactate, here's a decent article.

Ok sage how about the statement that people running 50 miles a week haven't realized their efficiency.......

And your quote on mmols,

Pretty sure your degree just isn't in ex phys.

Just a guy who reads 'stuff'.

Darth Pariah wrote:

SlowFatMaster wrote:

"LT pace is highly efficient at stimulating a shift in the metabolic mix towards glycolysis at a given pace. The benefits of which should be obvious."

This is the part I'm wondering if you are sure about.

Pretty sure. Correct me if I'm wrong. I'm basing this on my own reading and research. The literature I've read says that A) Skeletal muscle is highly adaptable to shifting energy sources to supply demanded ATP, and B) Exercise at the point where the byproducts of anaerobic respiration begin to accumulate in the cells provides the needed stimulus.

If anyone wants some light reading about lactate, here's a decent article.

http://jeb.biologists.org/content/208/24/4561.long

Are there any training implications of this, specifically related to tempo runs? Genuinely curious.

Darth Pariah wrote, in part:

"Yes, though I may have worded it poorly. I'm certain that stimulating adaptation towards aerobic respiration at a given pace is the #1 goal of LT training. My comment that it has "little to do" with FT/ST recruitment may have gone too far."

Darth Pariah also wrote, in part:

"LT pace is highly efficient at stimulating a shift in the metabolic mix towards glycolysis at a given pace. The benefits of which should be obvious."

OK, are you saying LT pace stimulates aerobic respiration at a given pace, glycolysis at a given pace, or both at a given pace?

I didn't know I had to have a degree in ex phys to be qualified to talk about this? Do we even have to have college degrees? No. In my defense I did take some chem and bio in college (where I did get a BS)...but so did most people on here probably. I do consider myself to be fairly well read and have years of experience in the sport beyond the NCAA DI level (from both an athlete and coaching standpoint). How old are you even? Finally I will stand by my statements (on this thread): If someone has only been running up to 50mpw then they probably have not realized their full potential in the sport of distance running for events 5km and longer because they have not maximized their Running Economy. Running Economy builds over time (think a decade or more), higher mileage, and consistency. It's a big reason people can still improve after age 25+ even though their Vo2max is dropping. High mileage certainly helps distance running performance and gains in Running Economy are key with that. 4 mmol of lactate is a general concentration level. Of course I know most people don't get measured and may have no idea what that feels like, but in lab studies it can be used as an effective number for an intensity around the Lactate Threshold. It is certainly not an end-all number, but pertinent enough to this thread/discussion. I'm more into having athletes "feel" their LT rather than looking at some canned number (or max. HR %). If you know what 4mmol feels like (and I do), then you have a pretty good sense of intensity around Threshold. Use that data along with running velocity/pace and recent race performances in the 5km-marathon range and you can pin it down pretty well...as well as see adaptations/progression in training.

It's Egun wrote:

Ok sage how about the statement that people running 50 miles a week haven't realized their efficiency.......

And your quote on mmols,

Pretty sure your degree just isn't in ex phys.

Just a guy who reads 'stuff'.

As someone who has only been over 50pw twice - I can agree that this point is valid.

"The primary goal of LT pace training" ???

There is no primary goal. There is nothing special about the supposed LT, it's just another training pace. It has been over stated since 1984 when it was hyped up as the big thing in training by Professor Conconi. JD latched onto this to sell books.

But we do have to learn how to use muscle recruitment patterns at a given pace. I think that every pace is equally important in training in different ways. Perhaps the 'tempo run' gets too much attention?

Yes ATP hydolysis is the source of H+, but pyruvic acid and lactic acid don't exist in the body, because the steps of glycolysis and glycogenolysis don't have an H+ to give up, they don't dissociate.

Darth Pariah wrote:

SlowFatMaster wrote:

Darth:

You sure about 4) ?

Yes, though I may have worded it poorly. I'm certain that stimulating adaptation towards aerobic respiration at a given pace is the #1 goal of LT training. My comment that it has "little to do" with FT/ST recruitment may have gone too far.

SlowFatMaster wrote:

"LT pace is highly efficient at stimulating a shift in the metabolic mix towards glycolysis at a given pace. The benefits of which should be obvious."

This is the part I'm wondering if you are sure about.

Pretty sure. Correct me if I'm wrong. I'm basing this on my own reading and research. The literature I've read says that A) Skeletal muscle is highly adaptable to shifting energy sources to supply demanded ATP, and B) Exercise at the point where the byproducts of anaerobic respiration begin to accumulate in the cells provides the needed stimulus.

[/quote]

Sorry Darth but you're contradicting yourself there. "Shifting the metabolic mix towards glycolysis" is the opposite of "stimulating the adpation towards aerobic respiration."

Whatever you meant, I don't believe' metabolic adaptions' are relevant. We already have those adaptions, they are basic physiological funtions. What we are looking for is learning how to run faster for the same effort i.e. neural adaptions.

dril wrote:

My bad. I'm pro train don't strain and anti calculators, formulas, and people who can't run tempo pace for 20 minutes but haven't tried running slower. Maybe "Add on" you aren't as fit as you think? And that's why you have to substitute a continuous 20-40 minute run for 2-3 minute repeats at the same pace.

The communal letsrun training knowledge has regressed to a sad level. You're now considered a troll if you suggest people run workouts at current fitness, not follow daniels paces blindly, and not use tempo runs for developing mental toughness.

Agreed, mostly. There is always going to be arguments about pretty much everything.

For what it's worth, I am on team Darth and Sage.

Sage, don't lower yourself to defending yourself against the nonsense. There aren't tons of guys on here who have managed to combine quality DI/OTQ talent with an ability to explain the basic principles underlying training philosophy with the kind of name recognition that you have. Some maybdo one or two of those things, but few donall three. Those three things together add a ton of value to the board, and are appreciated by the newer runners who need the advice and by more mature runners like me who like to see concepts explained well to others. (And, personally, I also like seeing that the training philosophy employed by quality coaches and runners often overlaps with my preferred Daniels approach to a great extent - as happy as I am with my approach, that is always affirming).

Trolls will troll.

S. Canaday wrote:

Running Economy builds over time (think a decade or more), higher mileage, and consistency. It's a big reason people can still improve after age 25+ even though their Vo2max is dropping. High mileage certainly helps distance running performance and gains in Running Economy are key with that.

Agreed on the training volume/running economy issue. But VO2 dropping after 25?

Maybe 45? or even later? Jack Daniels himself has noted this. His work on de-mystifying the 'aerobic development' dogma has been largely overlooked. If I outlive him, I will continuously point this out.

I'm 55 and I feel that if my VO2 has dropped, it's not noticeable. I test myself on a hill I used from my teens ownwards and my times in cycling are the same as in my early 30s and faster than my teens and early 20s, using the same old bike.

I don't feel like I'm a genetic freak and I don't believe in that concept in athletic terms anyway. I don't follow any special diet. I don't do and special training. But yes, my consistency over the last few years has matched my previous consistency in running. I feel the big development in early years and the big loss in later years is movement pattern adaptions. I'm glad this area is being investigated by some researchers. I hope we can eventually move out of the dark ages of misinfomation about exercise physiology, but it's going to take a long time.

Okay, some interesting and worthwhile points being made here.

If vo2max doesn't drop until your late 40s (my guess would be mid to late 30s, but I guess vo2max could drop earlier but cumulative miles could improve other limiting factors enough from that point to the late 30s such that performance improves despite small but steady drops in vo2max), what do you think accounts for the drop in performance when folks get to their late 30s?

I am honestly not being argumentative here. As a 46 year old who is running right in line with his historical PRs from college based on age grade adjustments, it is a genuinely interesting issue to me.

My hairy eared coach thought it could be related to the elasticity of tendons and their ability to store and return energy. Generally perhaps its related to muscular-skeletal changes rather than aerobic engine. I'm just a layman but its hard to imagine why your bodies maximum amount of oxygen utilization would change with age. On the other hand when I get out of bed each morning I can practically feel my tendons and ligaments weakening with each passing day. This could also explain why recovery periods often increase with age.

http://eknygos.lsmuni.lt/springer/442/25-31.pdf

Me too smoove. Good question, one which I have spent a huge amount of time pondering.

My best running year was age 45. My best competitive years from 1997 to 2009

I think we just get lazy in our sport. We do other things. The obsession that we had diminishes to be replaced by other things we always wanted to do, but were too tired from all the running.

Perhaps some athletes also get less selfish and more responsible towards family commitments? Or the need to commit more to work or whatever, but how long can one sustain a serious running commitment? How many years? For me it was quite a few years. Should I make a comeback? Well the obsession has to come back first and right now I'm having fun learning other skills.

What causes a decline in VO2? I don't think a healthy heart is going to decline much between 25 and 50. Why would it? A healthy cardiovascular system means new capillaries are forming all the time until we die. Can we have too much plumbing? I don't know.

heyyo wrote:

My hairy eared coach thought it could be related to the elasticity of tendons and their ability to store and return energy. Generally perhaps its related to muscular-skeletal changes rather than aerobic engine. I'm just a layman but its hard to imagine why your bodies maximum amount of oxygen utilization would change with age. On the other hand when I get out of bed each morning I can practically feel my tendons and ligaments weakening with each passing day. This could also explain why recovery periods often increase with age.

http://eknygos.lsmuni.lt/springer/442/25-31.pdf

I think elite young distance runners probably feel stiff in the morning too. The muscles relax during sleep and have to regain their stiffness during training. If you were awoken by something very frightening like a fire or a very loud noise or disturbance, the adrenaline would make you jump out of bed and be ready for some fast efficient running.

I try to avoid the age related decline mentioned above by ensuring my range of movement is the same as it was, with regular strides and sprints. If I was to try re-build my mileage to previous levels it would take some time and care not to over-do it, just as it did when I was in my early 30s and it took me several years to build to decent mileage.

Smoove wrote:

I wasn't struggling at all, I just didn't think an adult would be as dogmatically literal as my 9 year old; I expected a higher degree of nuance.

Darth, if you would handle this one next, that would be great.

http://www.letsrun.com/forum/flat_read.php?thread=8651585

I'm more familiar with the biochemistry than the physiology, but this one is easy. Unequivocal proof of pariah's trolliness. Your answer was essentially, "It increases VO2max," which is correct and supported by literature. Please consider pariah to be what his name suggests: outcast.

At maximal exercise, the majority of evidence points to a VO2max that is limited by oxygen supply, and cardiac output (Q) seems to be the major factor in determining oxygen delivery (28).

It's anecdotal, but those reasons definitely don't explain my scenario.

I walked on to my college team in college with no prior running experience (yay D3!). Got down to just under 14:20 my senior year. That was off of 40 mpw as a freshman, nonsummer running the following summer, maybe 45-50 mpw sophomore and junior years, them 55 mpw as a senior. I had a horrible diet, I drank a ton, and was always fighting off illness. The only extra I did right was to sleep a ton. think it is fair to say I was probably still underdeveloped because of my relative inexperience and low volume.

Life got in the way and I never ran consistently enough beyond my first year of grad school and didn't get appreciable better.

Fast forward to age 40 when I started training harder again. Decided to run my first marathon at age 42 and got up to 70 mpw pretty consistently, topping out at 75. Ran 2 more marathons at age 43 and 45 getting up to 80 mpw for extended streaks and topping out around 90 a few times, hittting 100 once. I drank a lot less and ate a lot better. Weight was about 145 compared to my college weight of 140 when setting PRs. The only intangible that is worse is sleep - a function of three kids and a career. If you take my better 5k through marathon performances during those stretches and convert them with an age calculator, they mostly line up with my 14:19 PR - all within :10 of that.

So if you look at that history, I think it is hard to say that it is a motivation or psychological issue that limited my absolute performance. I train more than ever and train as intensely as I did when I was in college. I've got more years of consistent volume than I ever did in college. Yet my performances slowed down by :63 (track) to :69 (road) as compared to college, with those times being in line when adjusted. It seems prettt clear that there is a change in physiology somewhere, and it is in line with the norms established by other performances. Muscle tone is a bit lower than in college, but I'm still at or near a single digit body fat percentage, so that could explain part of it, but not a full minute. It strikes me as a function of decreased cardiovascular capacity.

This thread is getting fairly painful to read. I find Steve Magness's podcast to be similar. You can question everthing and look into every molecule being broken down and resynthesized, but at the end of the day, you just want to be able to run faster.

ATP hydolysis is the source of H+, but pyruvic acid and lactic acid don't exist in the body, because the steps of glycolysis and glycogenolysis don't have an H+ to give up, they don't dissociate.

How does that help a runner get faster? 20 minute tempo runs help people get faster. If the mechanism by which tempo runs get people faster is useful and can be optimized, then great, but discussing which molecule gives up a proton isn't important for runners.