Time vs distance question

def runner b

I'd say runner A. I was taught that more time running was better than less for building aerobic system. Run a bit slower so you don't beat the crap out of your legs. If runner B ran with A he might be faster than 9:30 for 3200m.

7:30 down to 7:00 is basically garbage time for a 9:30 3200 runner. I mean it's fine for a gradual warmup the first few miles of a long run, absolutely, but the entire run?

Even 6:40 down to 6:20 is very easy for a 9:30 3200 runner.

B for sure. What possible value is A going to get out of running way slower for only 7 more minutes than B did?

Runner A. You max out aerobic benefit at around 60-65% max HR. This is because your stroke volume, (the amount of blood you pump with one beat) plateaus at around this point. So while running harder/faster will increase your heart rate, the number of beats per minute, it will not increase the force of contractions beyond the force at 60%.

So every minute that elapses Runner A and B are gaining the exact aerobic benefit. (Since there force of contraction is the same, just HR is different). Since runner A is running longer, they now also gain 7 additional minutes of benefit.

For a 9:30 runner, 6:20-6:40 pace is too slow to benefit any of the other systems, so you are not getting any additional benefits besides the aerobic benefit. You are however leaving yourself with less energy for upcoming workouts where you do benefit the other systems.

People respond differently to training. It's possible that each runner is doing the right run for him at this point. And you have to consider the context in which these runs were done.

So running aerobically is about nothing but stroke volume, huh?

There is a lot more to aerobic running than stroke volume. However, on non workout days, when you are just running mileage that is the emphasis. Other pieces of the aerobic puzzle come from different training intensities. If a runner were to do a tempo run, that would be a greater aerobic benefit than the 7:00 - 7:30 run. In the example provided, the alternative is 6:20-6:40 pace. This is a gray zone for a 9:30 runner because they have not yet reached the intensity that triggers different adaptations from the adaptations they get at 7:00 - 7:30. If they were to run tempo pace, which I would suspect would be around 5:30-5:45, they would "unlock" a whole new set of benefits unrelated to stroke volume.

Benefits such as lactate clearance, increased efficiency at pumping blood and oxygen circulation.

Since these benefits aren't really being effectively touched at 6:20 - 6:40 pace we can only compare the adaptations that are happening. The adaptations at these paces, you guessed it, are based on stroke volume.

Unfortunately it is not that simple

ncbi.nlm.nih.gov

Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review

Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly w...

Open link

Runner A will receive more of a pure aerobic benefit

Runner B will receive more of an aerobic threshold and maybe lactate threshold benefit.

Both types of long runs have their place in training. I tend to switch between a true easy long run (7:00-7:30 pace with the last few miles maybe 6:30-6:50) and a more progress to tempo long run where I’ll go 6:40s/6:50s and try to dip to 5:30s/5:40s by the end.

I’ve posted my experience before, but I essentially just did 8-13 mile runs every day ranging 6:30-7:30 pace average for about half a year and dropped a 4:30something mile in a random middle of the week time trial. My PB was in the 4:40s before that.

Don’t sleep on the aerobic long run!

Agree and disagree as someone who’s ran about a 9:15 equivalent.

Is that a super easy pace for a 9:30 guy? Yes. I stay conversational until probably about 5:50 pace.

Is it garbage pace? Absolutely not. The way I got to my 3k ability was very consistent 7:00 +\- 20 second miles day in and day out. My teammate who has ran 8:1x for 3k swears by doing his easy running at 7:00+ per mile.

They are doing basically the same thing and there's no way to measure 'aerobic benefit' of one run in hard numbers anyway. We could measure HR (both during the run and rest), draw lactate samples, use power meters, study the terrain and other conditions, even do muscle biopsy to study fiber types and tbh I doubt the answer could be more precise, at least not in a significant way.

But if runner B is beat after such run and runner A is not, maybe it's worth for runner B to make his easy pace slower. On the other hand it's not likely that A should speed up this kind of run unless he wants to.

Wow that was a very interesting read. I didn’t know that. Thank you for sharing!

If I could go back in time, I think I would have loved to study the body more and conduct experiments like this. How are bodies respond to different stimuli is fascinating.

For everyone reading this that doesn’t have time to read the article - I stand corrected. According to this study there are levels of moderate intensity that can actually increase the Stroke Volume, beyond the originally thought plateau. These increases do not occur in everyone though. These increases seem to only be a response for well trained athletes. How this applies to our hypothetical runners? We can not say. I would assume 9:30 is “well trained” but I can not guarantee that they would have the additional increase in stroke volume occur

True, but Dr D was pointing out that slow runs are not a waste of time as you do indeed get benefits even at easy pace. Esp helpful to know for a brand new runner. But, that doesnt mean he was saying only easy runs benefit aerobic development. I would say running close to threshold pace is a quality session of enormous benefit. Or maybe Jacob and Henrik should switch to all 65% pace? You cant run Q all the time, but running easy all the time aint good either. I would say the answer to this question lies in the even they are training for-- the 3200. 10 Miles is plenty of miles for slow long term benefit. Running it at tempo-ish/ marathon pace is even better for a nice quality session (B). So the answer is both in the grand scheme. Maybe B for the spirit of the question.

Thanks for the information. Can you tell me why the additional beats from the fast heart rate aren't helpful to Runner B, though?

Shouldn't we be comparing the total number of beats that Runner A and Runner B perform at this maximum stroke volume?

- Runner A's heart beats slower, but he runs for a longer time.

- Meanwhile, Runner B's heart beats faster, but he runs for a shorter time.

Setting total beats equal, an easy paced run seems to make more sense. Same targeted effect, but with better recovery of other systems.

I agree with you 100%. Faster runs like tempos and thresholds definitely have way more aerobic benefits. If you want to build up your aerobic capacity you definitely need all of these things.

However, the question was running 7:00-7:30 vs 6:20-6:40. So we aren't comparing slow running, to threshold and beyond. We are comparing slow running, to slightly faster running that hasn't quite yet hit threshold.

Depends on the rest of the general training scheme. If each get 2 workouts per week with one being around threshold and the other being at 3200 and faster speed, I’d give the edge to Runner A. More time on feet and a slow enough effort to get recovered for the next workout. Runner B is at risk of burying themselves in my opinion. Exception would be in an off season with no races or workouts to be recovered for.

Your argument being since they are both sub threshold why not choose the one with less stress. I guess I'll buy that. But 6:20 seemed at least close to marathon or tempo. I have not looked up tables on this guy.

27 downvotes so far really shows a lot about the lack of knowledge on this board, but also confirms why i tend to bail for a year or two at a time, come back for a month then leave again. similar to renato really. like talking to a wall, or worse usually.

anyway, yeah i feel what you are saying about EASY runs at 7:00 per mile or whatever, for sure. if you need an easy day/s, running at any slow pace is honestly fine. just got to get the blood flowing and keep your body in a rhythm.

my point was/is that doing one's LONG RUN at or even slower than the low end of what would be considered "easy" is garbage time. i 100% stand by that. easy/recovery runs are the time to run easy.

a long run should not be wasted by turning it into a long slog at easy/recovery pace, though. and again, even 6:40 down to 6:20 pace for one's long run is not fully taking advantage of the situation, although it's much more acceptable than 7:00+ pace the entire time.