Why marathon plans have speed workouts?

For marathon specifig training, there are no big benefits of faster running than threshold. Running economy is way more important than VO2 max for such this distance.

Only (small) benefit is better economy through really fast running, which can be done through strides. This is not so taxing for recovery since strides are to short to raise lactate levels to high.

Yeah the bulk of any marathon plan should be T & M workouts with good mileage & good long runs.

There's a place for a handful of speed workouts at 5k/10k but I wouldn't have them be true 5k predictor type workouts. Instead of 6-8 x 800 @ 5k on short recoveries, I'd rather see a bunch of 400s @ 8k/10k pace. A small number of sessions like that that focus on turnover are fine to include. Problem is that so many runners do something like 6 x 800 @ 5k once a week during their build & then try to race 26.2.

Strides a few times a week are prolly good enough for most to touch on some speed.

For the elite Marathon runners they do some speed workouts simply because they actually go fast.

2:05: pace is 72 seconds/400m . Whereas, 3h pace, is 1min42/400m pace.

While the 2:05 runner can sprint a 400m in probably like 50-52 secs. And most 3h runners can sprint a 400m in something like 57 seconds.

You see the difference ?

The 2:05 runner is going only 20-22 seconds slower than his 400m sprint, while the 3h runner is going a full 45 seconds slower than his 400m sprint.

Eliud Kipchoge runs a speed workout on the track every single week. Clearly it has a place in an elite training plan.

my two pennies wrote:

Eliud Kipchoge runs a speed workout on the track every single week. Clearly it has a place in an elite training plan.

That’s not a ‘speed’ workout. That is work faster than MP. I don’t think most distance runners have any idea about what speed training is.

MerkantilKreds wrote:

For the elite Marathon runners they do some speed workouts simply because they actually go fast.

2:05: pace is 72 seconds/400m . Whereas, 3h pace, is 1min42/400m pace.

While the 2:05 runner can sprint a 400m in probably like 50-52 secs. And most 3h runners can sprint a 400m in something like 57 seconds.

You see the difference ?

The 2:05 runner is going only 20-22 seconds slower than his 400m sprint, while the 3h runner is going a full 45 seconds slower than his 400m sprint.

This is right, though it's not just about the biomechanics of top sprint speed. Top marathoners are operating at a fairly high percentage of VO2max, but it's likely impossible to get much higher than the low 80s in terms of percentile. If you're there, then your aerobic headroom is really important, which means you need to be doing higher intensity training (3k/5k pace). Of course, you're not likely to improve your VO2max at that stage of your career, but you want to at least top it off before embarking on a specific training phase.

MerkantilKreds wrote:

most 3h runners can sprint a 400m in something like 57 seconds.

I think some aspects of your full post are valid, but do you really think the above is true—that most marathoners with PRs of, let’s say, 2:58-3:00 could run a 57 second 400? I would set the over-under substantially slower than that—just a guess, but 66, maybe? There are plenty of younger, speedier guys who might have the marathon as their weakest PR, but for every one of them I feel like there’s at least one old guy who hasn’t gone sub-18:20 for a 5k in years, or a woman with a 5:16 1600m PR from high school who has always been better at the longer stuff. And those folks aren’t sniffing a sub-60, let alone a 57.

My marathon PR is 2:59 and I haven’t broken 19 in a 5k. Or 75 in 400. I’m slow. But I did do speedwork kinda. My long runs were 14 slow plus 4 at barf-your-spleen pace for a total of 18. Last 4 way faster than marathon pace, like 6:20ish. And basically 10k race once a week. Made 6:51 feel manageable

I’m female. In case that matters

MerkantilKreds wrote:

For the elite Marathon runners they do some speed workouts simply because they actually go fast.

2:05: pace is 72 seconds/400m . Whereas, 3h pace, is 1min42/400m pace.

While the 2:05 runner can sprint a 400m in probably like 50-52 secs. And most 3h runners can sprint a 400m in something like 57 seconds.

You see the difference ?

The 2:05 runner is going only 20-22 seconds slower than his 400m sprint, while the 3h runner is going a full 45 seconds slower than his 400m sprint.

Wrong, most 3h runners cannot sprint a 400m in 57. I never ran 57 and are far below 3h :)

And most 3h runners can sprint a 400m in something like 57 seconds. [/quote]

What?

You're high if you think most 2:05 guys can run a 52, or most 3:00 guys can do a 57

justanEDnurse wrote:

My marathon PR is 2:59 and I haven’t broken 19 in a 5k. Or 75 in 400. I’m slow. But I did do speedwork kinda. My long runs were 14 slow plus 4 at barf-your-spleen pace for a total of 18. Last 4 way faster than marathon pace, like 6:20ish. And basically 10k race once a week. Made 6:51 feel manageable

That’s not speedwork, by definition.

To answer OP question, doing some speedwork early in a plan will support your more specific paces later when you get more specific. Think: get faster so that my LT and MP pace are faster when you work in them. Then, you might do some maintenance work on speed during your more specific phase but the primary emphasis will be what you describe.

It's a very boring schedule if it's just Tempo and Marathon Pace every week. Slow Marathoners don't really need anything fast but they also need things to help them stay engaged.

Marathon training plans have speed workouts so marathon pace feels easy on race day. It's also so you don't totally lose your speed when you (eventually) want to race shorter distances again, at some point. In most high level marathon plans, the percentage of mileage of the very fast speed work, is small, so it's not something you need to worry about being a "waste" of a large amount of your training time, since it's not. Also, since the percentage is small, it shouldn't leave you devoid of energy for your other more marathon-specific workouts.

It all depends on your goals. If you simply want to finish then do just mileage. If you want to improve your time & you are fairly maxed out on the amount of volume you can do then add quality.

I got about 15 minutes under those marathon times, but I couldn't run a 57 quarter for love or money!