is 3 x 5k tempo at 6:40 pace a decent predictor of sub-3 marathon potential?

No. Would need to be low 6:30's pace to be ready for a sub 3. This indicates you are in the 3:04-3:05 shape range. Any honest coach SHOULD be able to tell you that.

honest_questions123 wrote:

Assume about 70 mpw, little talent (hobby jogger), 3:08 PR, 5 minute rest on the intervals, and while tired, the workout did not leave me completely trashed.

This is confusing. You are saying 6.40 is your 3.1 mile pace but expect to hold 6.50 for 26.2 miles? Your 5k pace needs to be closer to 6.00!

Oh, my bad, sorry. I misunderstood the title of your post.

The above poster is correct - 3.05ish - but if you factor in a bit more training, decent taper, and better weather then you might come close.

How far out from your race are you? If it is a month or more then try a 13 or 14 mile MP effort. Whatever pace you manage in that will be roughly what you can manage on race day.

Run 14-16 miles as a race-day simulator. If your HR goes past 80% of you max at any moment, that isn't your race day pace and you're not fit enough to handle that pace.

Some Honest Coach wrote:

No. Would need to be low 6:30's pace to be ready for a sub 3. This indicates you are in the 3:04-3:05 shape range. Any honest coach SHOULD be able to tell you that.

^

This is correct.

3x 5 miles at 6:35 would be a better indicator of sub 3. Also, shorten the rest to 3 min.

No.

There's no predictor for the struggle of miles 23-26.

honest_questions123 wrote:

Assume about 70 mpw, little talent (hobby jogger), 3:08 PR, 5 minute rest on the intervals, and while tired, the workout did not leave me completely trashed.

It's too short to predict anything. It's hard to predict marathon performance because people's bodies react differently to glycogen depletion.

It's easier to predict your 18-22mi time and then pat you on the back and say "good luck".

With this workout....3-5 x 5k.....it needs to be in the context of a long run to really mean anything for a marathoner. So go run 10mi, fuel up, then start the workout.

Then longer marathon pace runs building up to 15-18mi. If you can run a 30k, 4 weeks out from marathon day, and you're not struggling to hold pace, you will be good.

Alan

That's not a great predictor, I think.

If you can do a 13.1 at 6:30 pace and not be trashed then you are sub-3, maybe. A better predictor anyhow.

Or, if you want to get weird - go no carb for about a day and then do your 2 x 5K tempo at 6:40. See how that feels.

I never understood long interval workouts for marathons.

If you have issues with mechanical efficiency-basic speed then 20 x400 or 10 x800 with jog recovery seems the way to go and a lot more scaleable-manageable for an inexperienced runner, particularly if workout is done solo.

To build true endurance you need to run often and run long occasionally. Easy start fast finish runs in the 12 to 16 mile range are the best for developing pace control under fatigue.

You first marathon is not so much a race as it is a fitness/concentration test.

IMHO, weekly training cycles for marathons in the 2:40-3:10 range need nothing more than

Three 5-7 mile runs at or just over MP,

One interval workout at 5k-10k pace,

One long run alternating between slightly shorter fast finish runs where fast finish is 3-5 miles done app. 15 secs faster than MP, and longer traditional long runs at conversational pace slightly slower than MP.

Short 2-4 mile runs done to injury tolerance as desired

After two months general training, do a flat 5k race to get an idea of your aerobic fitness, a month later do a half marathon to get used to racing long, then one month before your marathon do a race between 5k and ten miles to see how you are progressing. Be sure to get one true long run in 2-3 weeks before the marathon but don't over do your cumulative mileage.

Stay loose, go out slow, stay hydrated, find someone running your pace and you'll be fine.

Long interval workouts help with pace acquisition and running that pace when slightly fatigued. But to be effective you either need to run a bit before to extend the workout or do it the day after another workout. Do a shorter faster tempo one day then the next day do marathon pace tempo or long intervals. The pace of a marathon is easy. The issue is sustaining the pace when tired.

Alan

Sub3Pro wrote:

I never understood long interval workouts for marathons.

Isn't the whole idea of this type of workout to lower the lactate threshold? I would think that 6:40 or slightly faster would be pretty close to LT for someone who is in 3:09 shape trying to run sub 3.

honest_questions123 wrote:

Assume about 70 mpw, little talent (hobby jogger), 3:08 PR, 5 minute rest on the intervals, and while tired, the workout did not leave me completely trashed.

Well, you've got a lot of responses--most saying no. In my opinion, it depends.

My marathon PR is 2:55:xx which was run on a fast course (Chicago) off of 70 mpw. Those 70 miles had very few workouts in them (mainly just steady runs, long runs of 18-23 miles, and strides) and I highly doubt I could have ever run the workout you describe. A prior poster mention the oft referenced 1:25 half (6:30 pace) benchmark as an indicator of sub-3 ability. Well, my half PR (also on a fast course) when I ran 2:55 was just over 1:26. I've never run a sub 1:26 half.

So OP, I think the answer is that it depends. Is your sub-3 marathon attempt going to be on a fast course? I think you have a shot--especially if your mileage has been at 50-70 mpw for a while (like a year +).

Good luck.

I always do 3x5k in my marathon build up, but I keep the rest at 1:30 active (probably 8:30 pace), which makes the workout a better predictor for me. I have run multiple sub-3s with a low 2:50s PR and I usually hit 6:20-6:30 on this workout. 6:40s, especially with that much rest would confirm to me that I was not ready at all to run sub-3. If you can hit 6:40s on a shorter, active rest, maybe.

Alan, I wouldn't suggest the back to back workouts for a 3hr marathoner. Heck, I wouldn't suggest it for any marathoner.

And to the guy who ran 2:55 off a 1:26 who couldn't run 3x5k at marathon pace, has it ever occurred to you that you're the exception, not the rule? Most first time sub-3 marathoners need to have run 1:21-1:24 for the half.

OP, you may not be in 2:59 shape but we all know that it's hard to only shoot for 3:02. The fact is that 3:02 is much different than 2:59. Be realistic with your expectations. 3x5k at 6:40 pace is nowhere near a sub 3 indicator. But get out there and keep putting in consistent workouts and mileage, and someday, sooner or later, you will easily break 3.

reed wrote:

Alan, I wouldn't suggest the back to back workouts for a 3hr marathoner. Heck, I wouldn't suggest it for any marathoner.

And to the guy who ran 2:55 off a 1:26 who couldn't run 3x5k at marathon pace, has it ever occurred to you that you're the exception, not the rule? Most first time sub-3 marathoners need to have run 1:21-1:24 for the half.

OP, you may not be in 2:59 shape but we all know that it's hard to only shoot for 3:02. The fact is that 3:02 is much different than 2:59. Be realistic with your expectations. 3x5k at 6:40 pace is nowhere near a sub 3 indicator. But get out there and keep putting in consistent workouts and mileage, and someday, sooner or later, you will easily break 3.

Yes, that has occurred to me...hence my handle.

Long tempo paced intervals are the basis on my marathon training cycles. I tweak Daniels' Plan a bit and go with that.

The idea behind a heavy tempo emphasis is that the marathon should be a purely aerobic endeavor. The more you work on your aerobic/lactic acid threshold, the faster you can run while remaining aerobic.

Thus the emphasis by Daniels (and thus me) on tempo efforts.

If I were trying to actually race these races - you know, surge and be able to respond to surges - I might include more vo2max work (as Daniels does in his elite plan). But for those of us who are simply trying to get as fit as possible to run as fast as possible with a constatnt steady pace and effort, then there is good reason to emphasize long tempo interval efforts.

sdfasdfasdfdf wrote:

Sub3Pro wrote:

I never understood long interval workouts for marathons.

Isn't the whole idea of this type of workout to lower the lactate threshold? I would think that 6:40 or slightly faster would be pretty close to LT for someone who is in 3:09 shape trying to run sub 3.

LONG REPLY WARNING

I would argue that LT pace for an experienced 2:55 to 3 flat marathoner is no slower than 6:10-6:20 minute pace. If someone is attempting to break 3 on their first marathon, I'd be skeptical of anyone who hasn't recently broken 60 for 10 miles or 1:20 for the HM.

Put scientifically, Lactate Threshold or Lactate Inflection Point is "the exercise intensity at which the blood concentration of lactate and/or lactic acid begins to exponentially increase"

In practical terms, LT pace is generally defined as the pace a runner can sustain evenly for one hour.

According to McMillans, a 3 flat marathon converts to a 63 minute 10 miler which makes LT pace for 3 hr marathoners approximately 6:15 and 6:20 per mile.

So, to me, 3 x 5k at 25 seconds slower than LT pace doesn't mean much as a sub 3 predictor. However, if you ran 5 miles at 6:30-7:00 pace, drank some water and did 3x5k at 6:10 pace with two minutes rest and felt in control on the last repeat I'd say the workout was a good sign but not a guarantee for sub 3.

UNSOLICITED THOUGHTS

The reason humans can't run a hair under LT pace for hours and hours is mainly that we start to run out of available carbs for aerobic glycolisis somewhere around 75-90 minutes.

Because of this, the conversion factor from LT to MP pace gets exponentially worse the slower the runner. 2:10 marathoners only have to spend about a half hour in the fat burning, push through the wall phase. Thus, the Kipchoges and Rupps of the world can run just a few notches below LT pace and grit out the last miles at a pace not drastically different than their HM pace. However, your 'average" 4 hr marathoner spends almost 3 hours slogging away AFTER they exhaust their carbs . For this reason, "hobby joggers" typically run marathons multiple minutes a mile slower than their already pedestrian HM pace.

Runners in the 2:40 to 3:10 range find themselves in a tweener zone. As they have to run about an hour past carb exhaustion they need to go out conservatively but they still have to run at a aerobically taxing effort to hit their goal time. For this reason, you occasionally see stellar 1:18/ 1:16 performances out of moderately talented but disciplined runners but more often see (1:15/1:31) or (1:25/ 1:48) horror shows from the overconfident.

With all that in mind, the best ways for a runner to make the jump from 3:1X no mans land to 2:4x respectability are:

1. Become a more efficient and plain faster runner.

Efficiency is probably the least genetically limited component of distance running. Reasonable doses of 400, 600, and 800 meter repeats with short rest at current mile to 5k race pace is a generic prescription for improving functional speed. These workouts are typically done for aerobic benefits but I personally believe a lot of the actual benefit is from improved mechanical efficiency.

It's a cliche but striders and form runs never hurt anyone after a steady five mile run. People scoff, and rightfully so, at terms like leg speed velocity. But the fact is most 3:30 marathoners have crappy form, most 2:40 marathoners have decent form and almost all 2:10 marathoners have good to great form. Fix your crappy form and you will automatically improve Max Vo2, LT, and MP pace across the board.

2. Become a marathoner. I know many runners who failed to break 3 hours on their first try but eventually got down into the 2:30s. Why? Because they stayed healthy, ran consistently, and kept racing marathons. In the same vein, focusing on one benchmark workout or a particular goal pace is a self-limiting approach. I also believe avoiding knock down drag out workouts and torture long runs is critical for long term improvement.

3. Pick and plan your races. Temps above 70 degrees make fast marathons much, much more difficult. Bad turns, too many hills, lack of crowd support, no decent competition all have very real effects on your time. Most people don't have the energy or money to waste on sub-optimal performances. You don't have to PR every race but when you want to, spend the money and time to fly to Chicago or Houston and knock it down.

Good luck, stay healthy, and giver 'em h&:l.