Where does the benefit of more miles cap out, does it? (Read 1674 times)

As I put in mile after mile of marathon training lately, I have been wondering about the limit of where "more miles" is still beneficial.  Adding miles to a training regiment generally will improve that person's speed, but I assume that this will follow some type of diminishing returns pattern, and that at some point X more miles will not provide any appreciable benefit. 

In looking at how many miles are beneficial, I assume the pace of the runner has to be considered, a 6:00 min/mile runner will cover X distance in half the time of a 12:00 min/mile runner.  I assume (again) the benefits of running is a result of Time * Intensity rather than Miles * Intensity, and so the time spent running is really more important than the distance covered.  (This post is full of assumptions, please pick them apart.)

I made a small chart (below) that looks at distance covered for a fixed 11 hours a week of training at various paces.  According to that, if training was a result of time and we assume similar intensities a 5:30 runner doing 120 MPW is about equal to a 7:30 min runner doing 88 MPW is about equal to a 10:00 min runner doing 66 MPW as far as training benefit goes.  I picked 11 hours because it puts a 5:30 runner at 120 miles which was my wild guess as to what an elite marathoner might be doing, I could be crazy wrong, I didn't know any to ask.

Since this forum is full of people way more knowledgeable than me I figured I would throw this thought process out there and see where I've gone wrong.  I don't know if there is really a take away message from all this other than I have always thought in terms of miles per week and this might not be the most meaningful data point.  At 70ish MPW and a little slower than 7:30 average pace I don't think I am at any cap, however, I wonder if I pushed toward 90 or 100 if I might not hit / cross it.

Thanks for your thoughts.

It is unlikely that a person running 60 miles per week would be running 11 m/m very long.

 Unless they are 60+ years old or so.

Also, most folks who can run super fast in races don't run the bulk of their miles at the same super fast pace.  A 15 minute 5k runner probably runs most of his or her miles ~6-7 m pace.  Or slower.

 Yeah, I used 5:30 as the bottom end comparison number because that was a the lower end of what McMilan's calculator gave for an easy run pace for a 2:10 marathoner, I have no idea if that is actually what they run at or not.  I just threw 5:00 on the chart for the heck of it.

One of the advantages of getting faster is that it allows you to pack more training into a given time.  Saying that a 5:30 runner doing 120 MPW is getting the same benefit as a 10min/mile runner doing 66 mpw is not reality IMHO.

As for when benefit caps out, this will be highly individual.  But if we want to generalize to the population, I would say that it is above what 99+% of runners do.  It is also beyond what many runners are capable of doing.

I raced against a guy in HS, I was a 17 flat 5k runner and he was low-16s.  He was a year behind me but we ended up at the same college as teammates.  I ended up 16-low for 5k and he was mid-15s on 40-50 mpw.

After college, I cranked up the mileage.  By chance he got a job close enough that we could run together a couple times a week.  I was already at 80-90mpw when he arrived and he tried to keep up....I'd kill him on the longer runs and workouts.  Over the next 2 years, I ended up 100+ mpw and he got up consistently in the 70s, any higher and he started getting injuries.  The problem was, upping the miles STILL WORKED for him, right up until he got an injury set-back.  I ended up sub-31 for 10K and he got 31:30 on 80-ish mpw.  But he only broke 32 once as this was the only time he got to that mileage for significant time without being injured (he was injured soon after the 31:30).  So he was clearly a more talented runner as evidenced by his performances being well superior to mine on similar training levels.  He could have surpassed me and kept improving had he been able to handle the volume without injury.

For me, benefits ended right at the point I could no longer recover, which was consistently running above 105-110 mpw.

Absolutely amazing to me that some people run 100mpw.

Despite the time or distance ran, I would suspect that at some point the intensity must increase in order to continue to excel from running longer/further.

What I think is important is moving up to 98, 99, or 99.6% of your potential. I mean there are a lot of guys in this country who run low 2:20s marathons and are thinking about 2:19. Around the world it seems a lot of the best marathoners get into 140s or 160s for at least a few weeks. However, like it was said before being able to complete the workouts is more important than the miles. 

If someone has the ability to recover from 140 miles per week and do a lot of quality workouts (Nate Jenkins, Brian Sell, Peter Gilmore) then that's worth the effort because they just would not get as much out of 110 miles a week. 

I also think it's a mental thing. Personally, I really like seeing triple digits in my running log. Wether 100 is really better than 90 for me I don't know. Mentally however it feels a lot better to get that much in in a week. 

Sorry if I'm incoherent I just ran hills.