Ah ok, my apologies, I misread your tone 
I was going to do a similar workout today anyway. So don’t judge before you have all the information. A few lactate strips, a couple drops of blood, and now we have something to discuss. Since you apparently know everything already, maybe sit this one out. Thanks buddy!
Easy to do on the internet. No worries, mate.
But if I “sit this one out”, who is going to point people towards studies like this one?
I said I might have not gone hard enough to make it hurt. (…and I don’t have a >2k max sprint!)
Regarding the metabolism…in my very poor understanding, the first sprint might be fuelled with purely anaerobic energy, but while this is fast, it isn’t enough to go max again, and then the glycolitic pathway kicks in to restore the rest of the energy. But then, while that is happening, you try to sprint again, depleting it more, and needing to restore more…
(This is probably wrong, hah. I might need to find a book)
We were taught in ex fizz that the glycolytic pathway shuts down as soon as you stop exercise, and it is the job of the aerobic system to restore phosphagen levels.
This is somewhat correct, but better to name the pathways themselves. PCr pathway can cover the over but it’s actually the metabolites from ATP hydrolysis (H+ and Pi), calcium presence, and ATP/ADP/AMP balance, etc etc, activate glycolysis and aerobic respiration both.
Aerobic recovery of the cell’s state and PCr is mostly done with glucose and lactate to supply reducing equivalents, but glycolytic flux makes some ATP as well.
So just because PCr is being used doesn’t mean glycolysis is not happening. And if the cell state is not entirely reset to near normal levels, the aforementioned stuff will additionally mean more reliance on glycolysis. One of the articles above mentioned that glycolysis is messy and has lots of byproducts, etc… but that’s nearly every metabolic process. And if you ask me, the only real detriment to it is when people do too much too often, it leads to overtraining. However! There are really fun and interesting reasons to do training like this that’ll be the subject of an upcoming podcast.
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For starters I think the Strong First kettlebell articles took more than a little liberty with the use of the term anti-glycolytic. They aren’t talking to endurance athletes, and used exaggeration with the term anti-glycolytic to drive home a point. The original research on this training method is in Russian if I’m not mistaken.
Ok with that said I’ll take a shot. My background is engineering and general science, never took any biology or physiology classes in high school or college, and so this is a 50,000 foot view based on trying to pick up the fundamentals of exercise physiology over the last year or two. What I understand is that:
- PCr energy system rapidly fires and generates a large amount of energy for the first ~10 seconds. It then takes about ~2 minutes to recharge (aerobically) and about 6-8 minutes to fully recharge (aerobically)
- the Glycolytic energy system ramps up and takes over to cover energy demands for roughly 30-45 seconds
- then the Aerobic energy system takes over
and all of those times are approximate and can vary by individual, training, etc.
So for your 4x10-sec (20-sec recovery) sprints, my guess is that the first sprint is dominated by PCr and Glycolytic energy production, and sprints 2/3/4 become more and more dominated by Glycolytic energy production. The max sprints demand more energy vs 250% sprints, which placed a larger demand on the Glycolytic system, and so you saw a stronger spike in blood lactate.
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PCr takes varying time to get back to normal, 7-10 minutes in fast twitch fibers with low oxidative capacity. There’s also neural feedback inhibition that prevents motor unit recruitment that was a big factor in not being able to produce power in the later efforts. What really happens with later efforts is that all energy pathway activity is reduced because there’s less ATP use from the inhibition.
For reference, a normal 10 second max effort will usually raise my blood lactate 8-12 mmol, or about half of total seen here. Purposefully did no pedaling between efforts to not actually use the lactate. So it’s a diminishing return here, probably 8mmol for the first effort, 4 for the second, and 2 for the third and fourth. Goes along nicely with the decrease in kJ for each effort.
KB training fascinates me in that it doesn’t take into account how strong someone is. I’ll never be able to recruit maximal motor units with 50lbs because the force isn’t high enough, or even 100lbs. So take a stab at how this type of training might affect different motor units.
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I wonder about the difference between the 4x 10s sprints vs one 40s sprint. Does the tiny bit of recovery in the 4x make a difference? You mentioned your lactate was higher than from a normal 40s effort. Does it mean more moter units are getting recruited?
Isn’t the half-life of PCr resynthesis about 30 seconds? Seems like only in a really, really, REALLY sick person would it take 7-10 minutes.
ETA: Even in older peripheral arterial disease patients, who have problems delivering O2 to their muscles, the half-life of post-exercise PCr resynthesis is around 30 seconds. (Although the paper says milliseconds, that is obviously wrong).
Activation of phosphorylase at the onset of exercise is quickly reversed during continued muscle contractions. Perhaps breaking it up into 4 x 10 seconds instead of 1 x 40 seconds helped overcome this refractoriness?
Thanks, so if you have fast twitch with good oxidative capacity I’d guess it would be a little faster. Would be interested in your opinion of Tuesday’s workout (4 sets 4x15-sec ON 90-sec OFF, with 5min RBI) in the context of this conversation. Those were max efforts on the trainer (level/standard mode on Kickr direct-drive), its a little awkward sprinting on trainer but those were seated (makes it easier) and I focused on standing start cadence (actually pedals slowly turning, accelerate hard to >120rpm and the power just happened).
re: kettlebell indeed I find them interesting too. The short version is I credit kettlebell swings with overcoming posterior chain weakness and for the first time in 30 years I’ve been able to do goblet squats (dumbbells then kettlebells) and deadlifts (two kettlebells). Now capable of going to the gym and start using trap bar and barbell, they moved everything outside but I’m at the end of a 10-week resistance program and a little uneasy lifting in the gym with a mask (I don’t like how it restricts breathing a bit).
A 40 second effort actually has about the same lactate appearance for me. In someone more aerobic I would expect a bit less for the intermittent efforts.
@bbarrera your tuesday workout is a good example of repeated efforts I have people do. It does help build buffering capacity which, maybe counter-intuitively, enhances someone’s ability for glycolytic flux and make lactate. But it also helps expose larger motor units to oxidative stress, which is great for crits. A lot of folks don’t seem to need much of it, but some need it most of the year.
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Absolutely makes sense, to paraphrase in the context of this convo it burns off PCr quickly and a) forces the Glycolytic system to adapt and produce more lactate, while b) also creating an opportunity to make fast oxidative glycolytic fibers better at using oxygen. Fair interpretation?
Ok I think this is going to be like throwing you a softball, what about somebody with low glycolytic flux? My last INSCYD VLAmax is pretty low:
I’ve just ordered this book. I’m not sure I will be able to achieve many of the excersises, but I have zero sprint, couldn’t possibly ride at 250% FTP even for a nano second, but I believe, listening to Chad ,that even the most fast twitched challenged of us will improve our embarrasing attempt at a sprint 
Hi Lydia,
I recommend that the you listen to the author. He’s done a number of training podcasts and you can watch him on youtube. I found listening to a synopsis of the book in a one hour podcast and watching some videos very helpful.
The chief complaint about this book is rambling style of the writing which can make it sound more confusing than it really is.
In the end it’s very simple. You start with the dynamic warmup. You might want to do this for 1-4 weeks to build fitness before heavier work. After you achieve some level of general conditioning you start to add in the harder exercises like bulgarian squats, step ups, and walking lunges. The first time I did the walking lunges, my legs were ripped to shreds with DOMS for 3 days!
So, are y’all trying to be faster on the bike, or what? The only fast guys (and gals) I know slingin’ kettlebells around are track sprinters!
I feel personally attacked.
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Welcome to the Glyco club 
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