spreading mileage out over a day

[Tamy]

This site taught me the value of spreading miles out over a week by running daily rather than every other day to give less recovery time and improve endurance.  I keep asking myself if I could spread my mileage even more by running twice a day using less time for each chunk.  I'm not asking because I think it's such a great idea but because it would fit my busy schedule better.

My questions are:  Is there any benefit to running 5 miles twice a day every day instead of doing 10 miles once a day?  Is there any drawback to the twice a day approach?  These scenarios are for a person trying to qualify for Boston.

 

[Bonnie]

Tough question.  The short answer is you need to run, consistently, to improve.  The long answer is that two 5 mile runs do not equal the training effect of a 10 mile run.  Running twice a day is a great way to increase mileage when you have max'd out what you can run in singles (often because of time constraints, but also injury) -- it doesn't replace the need to be able to run for a long time - at once - easily.  BUT -- running the miles is ultimately the most important thing and it is always best to run as much as you can - if this means two 5 miles runs or no run -- then two 5 mile runs are better than none at all.

Especially for marathon training, being able to run a couple of days a week for 1 1/2 hours [in addition to one weekly long run of 2 - 3+ hours) is probably the most important aspect of training [personally, I am a strong advocate of NOT running the same distance/time every day, I think it can actually do more harm than good.  Instead, I believe you need to mix up your training a little: long run +short run /off+ 1 - 1.5 hour + short run + 1 - 1.5 hour (something fast is good) + short run+ short run, repeat].

[Jon Allen]

Previous posts on this:
http://fastrunningblog.com/forum/index.php/topic,228.0.html
http://fastrunningblog.com/forum/index.php/topic,793.0.html
http://fastrunningblog.com/forum/index.php/topic,1094.0.html

[Tamy]

Thank you both. 

[Sasha Pachev]

As long as you make sure that sometimes you do full 10 (maybe three times a week), then 5+5 on the other three days is a good idea to get aerobic benefits while reducing the stress.

There are two types of benefits. Benefits from running in the "zone" vs base mileage benefits. I would imagine fuel storage is better trained by running all of the miles at once. However, aerobic and neurological (learning how to run) benefits come about the same regardless of whether you split a 10 mile run in two. I would question the aerobic component if you split the 2 mile run in two, though.

[Bonnie]

I have to chime in for a moment -- I have been thinking a lot about this "10 miles/day" stuff.  I really don't think that 10 miles a day is what you mean here Sasha.  It really is about "time on your feet".  For me, 10 miles easy pace takes me 90` (9 min/mile pace -- maybe 8:45).  There is no way I should be running 90`/day.    Perhaps this makes sense for people who can run 10 miles in 70 mins or so ... but personally, I believe a recovery/easy day for a well-conditioned runner should rarely be more than 70-75 mins.  90 - 105` of running starts to get into a "medium-hard" run for just about everyone, and shouldn't be done every day.  I think that 10 miles/day as a target from people as slow as me is just a recipe for disaster.

[Sasha Pachev]

Bonnie:

I think the whole "time on the feet" concept is rather overrated. E.g. I can race 10 miles here at altitude on a flat course in about 55 minutes. So in that context let's compare 10 miles for me in 1:10 vs 1:20. 1:20 is more time on the feet, but is a very relaxing experience. 1:10 is 10 minutes less on the feet but it is not something I would do too often. If I run too many 10 mile runs in 1:10 I start feeling stale. I can do 13 in 1:40 day after day without feeling stale. However, if I do those in 1:25 (thus cutting 15 minutes out of the run) my performance in speed workouts and races does suffer.

"Time on the feet at intensity" would be a different story. But on a given terrain and under given conditions for a given runner this rather directly translates into mileage.

As far as how this applies to a slower runner. If the slower runner was racing shorter distances, I think optimal training for those shorter distances could be accomplished by running shorter distances. But, unfortunately, regardless of how fast you are you still have to run the same distance. So a 10 mile run for somebody who takes 1:30-1:40  to do it is more like a medium long run from the metabolic point of view. But at the same time he is essentially training for an ultra marathon, his marathon metabolically is really an ultra. So I believe possibly with some fine adjustments, the same distances apply to all speed ranges.

[David S]

Here is Pfitzinger's take on doing doubles -

http://www.pfitzinger.com/labreports/twoadays.shtml