Cottonshirt. your percentage attributions might be off. At speeds in excess of MLSS, you are not necessarily working 100% anarebocially. Just think of the mile and 5K, obvious examples of events that are mostly aerobic in nature
Cottonshirt. your percentage attributions might be off. At speeds in excess of MLSS, you are not necessarily working 100% anarebocially. Just think of the mile and 5K, obvious examples of events that are mostly aerobic in nature
wait a minute wrote:
Cottonshirt. your percentage attributions might be off. At speeds in excess of MLSS, you are not necessarily working 100% anarebocially. Just think of the mile and 5K, obvious examples of events that are mostly aerobic in nature
I took that to mean 100% of available anaerobic metabolism. Aerobic metabolism would be at 100% as well, of course. Correct me if I'm wrong.
Cottonshirt wrote:
Thank you for the detailed response. This is what I was looking for.
byteherder wrote:
Lack Tate wrote:
I think the answer lies in your concept of LT pace. It's not a constant as most people think. Typically, a runners LT pace will drift to a slower pace as a run progresses, but most runners start LT runs below their LT current pace to compensate. For example, a 6:00 pace may be an 85% max HR effort for the first mile, but by mile 5 that same pace is now 91% effort. We end the run and call it a day.
If, however, you ran indefinitely at say 90% max HR (this is roughly where LT occurs in most people) you might be running 5:50 for mile 1, 5:55 for mile 2, 6:00 for mile 3 and so forth. Eventually your LT will be rather slow due to fatigue, energy, dehydration, etc.
Dors that shed some light on your question?
It literally does not work like you describe. Your LT does not change every mile you run. If your LT pace was 6:00/mile you reach your steady state lactate level after about 5 minutes and for the next 50-70 mins you can hold that pace without lactate accumulation.
The question is why after about 60 min, the lactate levels begin to rise again?
Actually, if you monitor a run with a heart rate monitor, it does work this way. However, this is based off of max heart rate percentage, not a finger prick test. Obviously heart rate is not a precise measure of LT, so while what you describe may be what is truly happening, the average runner using a heart rate strap percieves and interprets the data differently, thus my description of pace change with constant heart rate.
The conclution I gave, however, is the correct answer to the OPs question: eventually your LT will be rather slow due to fatigue, energy, dehydration, etc.
I still don't believe you understand the question you're asking. Lol
Donut Dan wrote:
I still don't believe you understand the question you're asking. Lol
Possibly! I think my understanding of lactate threshold needs help, which Cottonshirt at least got me started on. Though Cottonshirt's comments on fatigue are specifically what I was looking for.
The key factor in race pace slowdown is the non-availability of Dill Pickles. Get enough of the fabled Dill Pickle and the pace will stay up.
dad bod wrote:
Let me rephrase the question...
At distances run faster than anaerobic threshold, the accumulation of lactate is the primary limiting factor. Correct? Say your maximum lactate tolerance is 10 mmol (just a hypothetical figure, no idea what it typically is), the pace you can hold for mile/5k/10k/HM is whatever brings you to that lactate level by the end of the race.
But for distances run slower than anaerobic threshold, you never come close to that lactate limit. So what is the pace-limiting factor?
Accumulation of lactate is not the primary limiting factor in faster races. It is a factor in so much as glycogen depletion in the most powerful fibers affects every race distance which is felt near the end of the race, but this happens regardless of lactate accumulation.
In all races, you have a skill level of learned neuromuscular control and an output of nervous energy which has to be optimal for ideal pace matched to that skill level. Our muscles are controlled by our nervous system before they actually use metabolic energy sources, so your efficiency of movement has to be practised with millions of repetition of movement, just like any other skill.