From the books and articles I’ve read for general heath and fitness more frequency/less mileage is better than less frequency/high mileage. But this is more about injury prevention than any other benefit.
Keep most of your runs at conversational pace. Also include one or two sessions of intervals per week (on your shorter days and never back to back). This will also improve your cardiovascular fitness
I remember reading something about growth hormone peaking around 45 minutes of running?
Many, many, moons ago, when Runner's World was still sort of interested in racing and running fast, they had an article more or less exploring this. The article referenced a study done on British female marathon runners looking to identify the variable most common to running a good marathon. It turned out to be the number of runs taken during the prep period. It was not overall mileage. That was the second most common variable. The article also said that an hour run improved endurance, I think that was the word, this was from a long time ago, by only 20% more than a half hour run. Based on that if you're going to spend an hour each day running the best way to do it would be in two half hour installments.
Of course you don't need to limit yourself to an hour a day but the Law of Diminishing is a real thing and I know there have been studies showing that in any run most of the benefits you accrue come in the early part of your run. Going back even further in time there was a guy from my club in DC who was in the AAU Six Mile championship where Gerry Lindgren and Billy Mills got the Six Mile World Record. He'd been doing 120-130 miles a week in one run a day. Lindgren told him to do the same mileage but to do it in two runs a day. He told me he ran much better once he made that switch. There's a reason that nearly all national and world class runners run twice on most if not all days.
If I decided to get serious again about racing as fast as I could and was going to run for an hour and a half on most days I would do it with a couple 45 minute runs or some close variation, maybe 60-30. But there is also value in long runs so I'd still get in one or two a week of at least 90 minutes. This question is usually treated as an either/or thing and it's not.
It just depends. Recreational runners doing 1/2 (or even > half) of their weekly mileage in their long runs would probably be better off shortening that & adding a couple miles to their other days. Frequency would be beneficial in that instance.
For runners with big goals at the longer distances, specificity matters. You're probably not even answering this question because you're probably running most days & getting in the miles.
Doubles always worked better for me. Admittedly, 3K/5K were always my best distances, so it could just be my body type. I'm definitely not your typical skinny distance runner. But trying to get in decent mileage in singles always just wrecked me. Even back when I was doing "high mileage" (for me anyway), I could handle an 8/4 double no problem, but a single run of 10 miles would feel too much for an easy day.
I remember reading something about growth hormone peaking around 45 minutes of running?
Yes, you can keep breaking every run into at least two smaller runs until you hit the Plank length at which point our current theories of spacetime and Lydiaard break down and we probably have to reckon with quantization of space and motion through it and by consequence training benefits.
100% of the top 1,000 runners in the world double. So if you didn't want to think about it and only followed examples of success, than double.
If you want to understand hormones, muscle development, recovery, aerobic and anaerobic development, etc., before making a decision—Andy Galpin has a 4 hour explanation of the science of endurance on YouTube (it is a dense listen). The takeaway? Doubling (or more) is far better in almost every conceivable way.
If you're just building volume and you don't plan to run a race longer in duration than any of the (shorter) runs, then yes doubling with shorter runs is generally fine.
Your body adapts far better to a greater frequency of signalling events.
Not only that, you'll likely need a much longer recovery time after the long run (which may defeat its purpose).
However, It does depend on what you're training for, and how the run fits into your training week. If you're specifically training your endurance for a long race (such as a marathon), then a longer run will likely provide a better stimulus for the specifics of that event. However, it comes with the cost of greater recovery time.
If the purpose of the run is to build general fitness/mileage between harder workouts, then multiple short runs would be the better option.
Your body adapts far better to a greater frequency of signalling events.
Not only that, you'll likely need a much longer recovery time after the long run (which may defeat its purpose).
However, It does depend on what you're training for, and how the run fits into your training week. If you're specifically training your endurance for a long race (such as a marathon), then a longer run will likely provide a better stimulus for the specifics of that event. However, it comes with the cost of greater recovery time.
If the purpose of the run is to build general fitness/mileage between harder workouts, then multiple short runs would be the better option.
Great post.
The correct answer to the OP is "it depends."
For general aerobic development, two signaling events per day are better than one. (The Magness and Marcus on Coaching podcast has a lot to say about this.) Also better for recover if we are talking about your approach to days between workouts.
For muscular and mechanical preparation for longer events, certainly for a HM/marathon, longer daily runs are important (although most elite marathoners are doubling, for your 2:50-something 60mpw type I think there is an argument for doing that as much as possible in singles.)
—Andy Galpin has a 4 hour explanation of the science of endurance on YouTube (it is a dense listen). The takeaway? Doubling (or more) is far better in almost every conceivable way.
Do you have the name of the YouTube video or a link? I’d love to listen to this.
100% of the top 1,000 runners in the world double. So if you didn't want to think about it and only followed examples of success, than double.
If you want to understand hormones, muscle development, recovery, aerobic and anaerobic development, etc., before making a decision—Andy Galpin has a 4 hour explanation of the science of endurance on YouTube (it is a dense listen). The takeaway? Doubling (or more) is far better in almost every conceivable way.
I think you are right, but you are using people who run 80+ miles per week as an example? For 90% of us we are running 20,30,40,50 MPW. Im coming at it from a 12-18 y/o runner standpoint so they are running 10-40ish MPW. So the question is do you need to run doubles if the mileage is manageable enough to do it in singles? Which i guess is what the whole thread is about. But I don't know the answer. I do know the young folks (teens) use the doubles to essentially double their mileage, rather than split it, which aint good. I don't think they look at it like we are here. Do you gain injury risk disproportionately to aerobic benefit? Recovery is a multi day event, not 8 hours. (I see these few HS kids that come to me at 630pm having already run in the morning and im impressed, but they look like death warmed over.)
What a great study that needs to be done...find the break point of splitting up 4 miles a day, 6,8,10 and where the benefit kicks in. Seems like a good fit for Seiler's group.
Short doubles are better but most of us are limited by time. Even if you can head straight out the door to run you've still got to get dressed, wait to stop sweating, shower and change, and you've got to fit it around eating, sleeping, work, family etc. Hard to justify if you're running less than 10 miles a day despite probably being more effective at almost any level of mileage.
I remember reading something about growth hormone peaking around 45 minutes of running?
Many, many, moons ago, when Runner's World was still sort of interested in racing and running fast, they had an article more or less exploring this. The article referenced a study done on British female marathon runners looking to identify the variable most common to running a good marathon. It turned out to be the number of runs taken during the prep period. It was not overall mileage. That was the second most common variable. The article also said that an hour run improved endurance, I think that was the word, this was from a long time ago, by only 20% more than a half hour run. Based on that if you're going to spend an hour each day running the best way to do it would be in two half hour installments.
Don't suppose you've got a link to this or the study? Would be interested to read it.
Many, many, moons ago, when Runner's World was still sort of interested in racing and running fast, they had an article more or less exploring this. The article referenced a study done on British female marathon runners looking to identify the variable most common to running a good marathon. It turned out to be the number of runs taken during the prep period. It was not overall mileage. That was the second most common variable. The article also said that an hour run improved endurance, I think that was the word, this was from a long time ago, by only 20% more than a half hour run. Based on that if you're going to spend an hour each day running the best way to do it would be in two half hour installments.
Don't suppose you've got a link to this or the study? Would be interested to read it.
Sorry. No. I think RW published it in 1977 or so. I'd need to find the actual magazine it was in and then see if it had actually gotten online anywhere. Maybe someone who's way better than me at searches could find it but doing that is way beyond me,