Just as a basic example, does running 3 miles in the morning and then 3 miles after work equal the ability to run for 6 miles? Or, is it always less than that?
Just as a basic example, does running 3 miles in the morning and then 3 miles after work equal the ability to run for 6 miles? Or, is it always less than that?
There's certain benefit you get from running longer in one run rather then breaking it up. I would not recommend doubling unless you run far enough each day that all runs would be excessively long and thus become anti productive or time constraints force you to double.
Each has their advantages. The big thing with doubles is they help with recovery and injury prevention.
Steve Magness talks a bit about doubles vs singles in three articles here:
http://www.scienceofrunning.com/2009/10/is-9mi-once-better-than-45mi-twice.html
Seems like he thinks breaking a run into two shorter ones doesn't hurt you as long as your'e doing aerobic workouts and a long run. This is in-season once an aerobic base has already been built.
Personally, I've always done at least an 8-5 if I'm going to double (my standard is a 10 and a 5). So if I was doing less than 13 I'd almost always single. As of late, I don't double very often even when my mileage is in the 90s, so I'll have non-long run days at 13-miles.
I've moved towards this I think due to a combination of a night-owl sleeping schedule and it just being mentally easier to get it all in once I'm out there. (I often do a similar thing in the winter when there's hardly light and it's better to run all my miles mid-day when it's warmest.) I need to start adding back in doubles though. I think I feel better when I'm doing them consistently and if I want to get mileage back over 100 I need to double.
Background: I "ran" in high school w/o much of a coach and didn't really start training till so. year of college. I ran at a strong DII program and had some success in XC and on the track by the end of my career.
When I tried bumping up my mileage from~65 to 75-80 through incorporating 3-4 doubles per wk (in season w/ workouts) I actually gained weight and didn't feel as fit through workouts. Through the rest of my collegiate career, I found that I really had to get about 70 through singles before I really felt like I was gaining anything by doubling. Injury is a different story.
I would say the sum of runs doesn't give you the benefit of a single run till you hit a "threshold" which I'm sure differs both by person and fitness level.
Each workout has a benefit. Think of doubling vs singling as choosing what benefits you want to get from the day's running. This decision doesn't happen in a vacuum, though, and you pick workouts based on how you feel from the last few days and how you want to feel/plan for the next few days. You want to be doing a variety of workouts. Singling vs doubling is not some kind of borderline choice between similar workouts once you understand how each run stresses your body and asks it to recover/adapt. I'm going to oversimplify (and somewhat ignore, too, that there is a lot of variance within workouts due to duration, effort, terrain, fueling, etc.) and give you an idea of what happens during aerobic runs of various durations.
30-45 minute run: Basic aerobic run. It's long enough to get you warmed up and into a steady aerobic heart rate zone. Hydration and fueling should never become an issue in this run. You should finish before any part of you really has an opportunity to deplete and injury risk should be minimal. You will have increased blood flow and should enjoy the benefits of many natural boosts to your body, including natural human growth hormone production. This is an ideal run for basic aerobic fitness or recovery. It's hard to go wrong here.
75 minute run: This is about as long as you can run aerobically before hydration and fueling become an issue; much longer and you begin to deplete and repetitive impact stresses start to add up. You would have already gotten many basic exercise benefits at the 30 minute mark, so after that you are trending toward the area where your run starts to become endurance-specific. Stopping around 75 minutes means you get some true endurance training and should recover from any fatigue by your next run so long as you rest and refuel properly.
120 minute run: This is clearly a long run. Hydration and fueling will become an issue. You may even approach your fueling limit (the wall) depending on your glycogen/calorie storage and recent physiology. Repetitive impact stresses will add up. Recovery from a run this duration or more requires good rest and refueling. By doing a run like this you should recognize that you are trying for significant endurance adaptations when you recover, but this is a stress to your body that will only be absorbed in a healthy way if you emphasize correct recovery after it, both through refueling energy stores and allowing muscoskeletal systems to repair.
On both extremes of the spectrum you should recognize that going less than 20 minutes means barely scratching at aerobic benefit and only preliminarily getting the blood flowing. Running over 120 minutes means small additional aerobic benefit and large risk to depletion and energy.
What does it all mean and what does this have to do with doubling? Look at your schedule and your goals. If you come up to me as a veteran runner and say, "How can I become an aerobic monster?" I'm going to tell you that your bread and butter day is to run 75 minutes twice a day and make sure between the two runs you eat a solid meal and take a huge nap. But I'm still going to tell you to squeeze in one long run one day that week and that's going to require two really easy days after it. I'm still going to tell you to do a faster workout that may require an easy day before it and after it so you aren't flirting with injury.
Why does this get confusing for people? Typically because the runner is trying to do something like 1 to 1.5 hours of running and this would give them a solid day. You need to make a decision. Go run 75 minutes and get a real aerobic benefit OR go run 20-45 minutes twice and get some very basic aerobic benefit along with some recovery.
Have more time and energy? Go run 75 minutes twice, but if you go any longer you're going to need real recovery. Pretend you have 2 hours to run every day. Don't run a 2 hour run every day (Ed Whitlock might differ). You're better off running 75 minutes and then 45 minutes or vice versa. That actual 2 hour run should be a once a week kind of deal on a day where you single. Some coaches like Joe Rubio will let you do a medium long run each week, too, that's more like 90 minutes.
If these durations seem easy to you, then run faster. If these durations seem hard to you, then run slower. You may be doing it wrong.
Primo Numero Uno wrote:
There's certain benefit you get from running longer in one run rather then breaking it up. I would not recommend doubling unless you run far enough each day that all runs would be excessively long and thus become anti productive or time constraints force you to double.
Wrong, terribly wrong. Doubles have benefits that you can claim even if you are not a high mileage guy.
Two 30 minute runs are more efficient than 1x1h run in some aspects. Lots of 'good things' happen in the first 30 minutes of any run, and then it slowly diminishes. It doesn't replace the role of medium and long runs in any full capacity, but it sure has its place.
OP, Here is a good thread from a few years back about doubles vs singles.
100 mpw in singles or doubles?
As Soprano stated- in base phase make sure your first run is always longer. 8 > 4 + 4
Why do you think you long run? It builds strength. The longer you are out there the more time that physiological processes are occurring. For example, you are going to build more capillary beds on a 9 mile run than a 6 mile run.
It goes get to the point though that you just can't run everything in singles due to energy, injury, or time.
Doubles in season are a different story. More a means of injury prevention. I like doubling with just a very light 15-20 minutes in the evening if I did a workout that morning to help get some blood flow back into the legs and shake things out a bit. I'm not out there for the aerobic benefit.
I usually find I get to 70-75 (long run accounting for 15-16) in singles then will like to start adding doubles.
As noted in other's posts, it depends. For me it largely depends on weekly schedule, time constraints, and recovery levels.
Monday 60 – 70 min
Tuesday 6xmile tempo 6x200m R
Wednesday 60 min – 70 min
Thursday 3*(1200-1000-800) Equal time jog
Friday 60 - 70 min
Saturday 120 min Progression run
Sunday 60 – 70 min
Using this weekly context on Friday or Sunday your legs can feel dead and need to split your runs 40 min Am and 30 min pm to get the mileage in.
Conversely, something that not everyone addresses is the time between runs. When running singles individuals typically run the same time every day in and day out. Let’s say that the athlete runs Thursday’s workout at 7pm and follow up with split runs Friday 40 min at 7 am and 30 min at 6 pm. The workout Saturday may suffer if it is in the morning.
So to tie everything together, write out your training schedule in pencil, listen to your body, know your schedule outside of running, and be willing to change.
OP:
Everybody is so anxious to jump into the typical singles-vs-doubles debate that your pretty simple question didn't get answered.
No, two smaller runs do not equal the ability to run the sum of those runs. You might be equally "fit" from either, but your body will only adapt very specifically to only what you expose it to.
What is your pace for your shake-out runs compared to your routine easy runs?
The benefits of doubles are similar to the benefits of intervals vs single hard efforts:
1) They make an equal workload easier.
2) They allow you to increase the workload without increasing (or with a smaller increase in) injury risk.
It is possible that doubling results in bigger increases in some systems (like mitochondria development, for example) relative to the increase in stress on other systems (like the musulo-skeletal system, which might come under a larger amount of stress at the end of longer runs when you are fatigued). That is just conjecture though.
Other possibilities are that doubling helps with body weight control or that it is simply correlated with more serious training.
This is an interesting thread and the thread starter is our LetsRun.com tshirt winner for Thursday. (We're giving out LRC tshirts to starters of interesting threads).
Email me at
However, the title needs to be changed. Clearly people who have found this thread like it, but I never would have clicked on it , not knowing what it was about.
Anyone have a suggestion for a new title?
Wejo,
My proposed title: "Are there congruent physiological adaptions in 2 shorter runs vs 1 longer run?
Drew
jimmyjonny wrote:
Wejo,
My proposed title: "Are there congruent physiological adaptions in 2 shorter runs vs 1 longer run?
Drew
let's play the fancy title game
"On the observed benefits and stimuli of doubles: half the workload twofolded versus a single session?"
value of doing two training runs per day- discus
I think the question the OP is asking is quite specific. Perhaps the thread title reflecting that question would be "do doubles confer the same endurance benefits as singles?"
What's old is new again. Numerous threads on Letsrun on this topic. The reason why you double isn't to "break up miles". You do doubles to give you two stimuli each day.
wejo wrote:
This is an interesting thread and the thread starter is our LetsRun.com tshirt winner for Thursday. (We're giving out LRC tshirts to starters of interesting threads).
Email me at
wejo@letsrun.comHowever, the title needs to be changed. Clearly people who have found this thread like it, but I never would have clicked on it , not knowing what it was about.
Anyone have a suggestion for a new title?
"Do two runs in a day have the same physiological effects as a single run of the distance that equals the sum?"
malmo wrote:
What's old is new again. Numerous threads on Letsrun on this topic. The reason why you double isn't to "break up miles". You do doubles to give you two stimuli each day.
http://www.letsrun.com/forum/flat_read.php?thread=2372073
+1
Maybe a good way for the OP to think about it is:
Your body does not necessarily know when one calendar day ends and the next begins. We all recover at different rates, so it cannot be universally said that once someone get a full night's sleep, he is in a new 24-hour day and ready for another run. Some runners might need 2 or 3 days before another stimulus, other may only need 6-8 hours between runs.
Is 100 MPW in 12 runs equal to 100 MPW in 7 runs? No.
In the first scenario, the average run is 8.3 miles run with a frequency of approximately every 14 hours.
In the second scenario, the average run is 14.3 miles run with a frequency of approximately every 24 hours.
If you lined up those two hypothetical runners against one another for a 5K, and then for a marathon, you'd probably get two different results.
A very deep discussion. You could literally write a book about MPW and how it is a quite meaningless reduction of what makes up someone's training.
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