Parker Valby, a distance runner at the University of Florida, recently won the women's NCAA cross country championship and two weeks later broke the NCAA woman's record for the 5000 in a time of 14:46. She broke the record by about 16 seconds and did it on an indoor track (her time broke the indoor and outdoor records). https://www.youtube.com/watch?v=uhVdG4vRDbY


Two weeks ago she destroyed the Collegiate 10,000 Meter Record. In her debut at the distance, she ran 30:50 and took 28 seconds off the previous mark. https://www.youtube.com/watch?v=fCyxF265kzo


She only runs three times/week (at most 30 miles) and cross trains the rest. Uses a ARC trainer to cross-train.


https://www.youtube.com/watch?v=5gWuLgqJmE0
https://www.youtube.com/watch?v=dsQ-0gmAA5s

I was probably close to 3-3.10 hour marathon shape last year (1.26 HM) preparing for duathlons. I was aiming for 8-10 hours training consistently per week. I'd aim for 4 runs and 3 cycles per week about 50/50 time split. A solid week would be
1 x intervals run 1 -1.15 hour (different length intervals at different points)
1 x intervals bike ( I tried to focus on longer intervals e.g. 2x20 etc)
1 easy 1 hour ride
3 x very easy runs, trying to make one a bit longer (maybe 90 min) the others 1 hour
One longer ride on weekend. If longer (3 hours would try keep it easier) if 2 hours more tempo type pace.
Sometime might get in a 4th 1 hour ride - typically tempo.

A lot of the riding on the trainer so 1 hour is a full 1 hour.

I found this load fine in less stressful patches but harder when work stress arose and to work on weekends, young kids, family time all competed for my time. Doing it week in week out consistently without sickness or injury built great fitness.

If my goal was sub 3, I would have made it 5 runs and only 2 cycles or even 6-1. Would have done more and longer long runs, and workouts with more challenging pace at end of long runs. Would have had to workout nutrition (stomach fine for cycling less for running). Marathon seems to be more about run endurance, and if I had run and missed it would have been down to this being the issue for me.

I think your run mileage is on the light side if it's a serious goal.

That 3:36, how much was very little? Like 10 mpw or 30? If you can do a 3:36 on very little training then general fitness gains will be enough to get you close to 3:00.

As a rule of thumb for running cross training you should maximize your running volume nearly to the point that doing any more will lead to overuse injuries. From there you can add in cross training.

I'm guessing that your fitness can still be improved generally before worrying about if HIIT or Z2 is more optimal for you. Doing a bit of everything is probably the safest bet.

Lastly weight is critically important for running. 2s/mile/lb is what they say. If biking helps you lose a few extra lbs then that's obviously great.

It's generally difficult to answer questions phrased as "if myself as an individual trains in this manner can I expect this very specific result?". Without a complete training history it's hard to guess, even with such a history it's an educated guess.

I just ran my first open marathon in February and managed a 3:08. I peaked around 55 mpw with most weeks in the low 40’s and was running 5 days most weeks. I was also biking 2x per week. I think I ran pretty terrible lines on a pretty twisty course (Skidaway Island, Ga) and missed two turns that cost me pretty dearly. My watch and the guy running near me had us at 26.6 and a 3:05 pace, which is what I thought I’d get based on training paces and a 1:27 half leading in.

Until the final build I was doing the Fulgaz IM series, but the efforts I was putting into those 1hr+ TT’s would wreck me for a couple days after. So I halted them and would do one tempo or sweet spot ride and one easy aerobic ride per week.

I qualified for Boston ‘25 and would like to have a go at a sub-3 there. In prep I’ll increase to a steady 60 mpw and keep the 2 bikes. I think that’ll get me pretty close.

Edit to add: this was off of just under 2 years of endurance training after taking nearly 10 years off and getting fat (6’4” 260) then skinny (175) again.

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It seemed like a good idea at the time. . .

Can you run a 1:25 half OP? Going to be hard to cross train your way to a sub-3 if you don't have the speed for it. I would start there. There aren't really any shortcuts in the marathon. I would say most people going sub 3 need at least 50-60mpw to get there, if not more. I don't think it's as simple as running 30mpw & calculating how many bike miles make up the difference. Lifetime mileage matters. PBs matter. I've had good luck in open running races off of ~40-50mpw, in full triathlon training. But I came to triathlon with a running background & put together multiple builds topping out at 80-100+ mpw. It's totally different for me now. I can get away with more of a swim/bike focus in training & still run well off of 50-60k/week. I think it'll be hard to cut time & cut miles at the same time if base fitness isn't where it needs to be. You're going to need sub-19min 5k & 39-flat 10k speed at a minimum. You'll probably need faster than that to have a chance on the lower mileage. My advice would be to not put pressure on yourself for a fall build. Hit the prerequisite times and find out how to balance the cross training with the training required to do that.

Really comes down to what your strengths/talents are, but I'll throw my data into the mix.

I'll be going for sub 3 this fall, and have a 3:05 full pr from two years and a 1:23 half pr set earlier this year.

I ran on and off for years before coming into tris in 2020, but have spent the majority of my time recently on the bike trying to hit T2 in good shape for a change.
For numbers sake - my 2023 totals were 230 hours on the bike vs 60 hours running (450 miles total). A lot of the bike sessions were short hard efforts on the trainer - ftp/ss blocks, zwift races, etc. I definitely think that has carried over well to my running as did the general bump in training hours vs running exclusively. I've kept that trend up this year but have increased bike volume further with additional z2 as I've become comfortable with the training load.

For my fall marathon I'll probably do more running, likely in the 30-40 mile range for a 6-8 week stretch, with easier riding thrown in to replace easy run miles just to keep the legs used to spinning on a bike.

Thanks everyone for chiming in, appreciate it.



For the fall build I was hoping to break 3:30, so I apologize if the opening post was confusing. Long term goal BQ, which on paper will be 3:10 in a few years, but with how competitive Boston is, sub 3 is more likely to get me in the door.

Thanks for the benchmark recommendations. I havent done a stand alone 5/10k lately, however I'm coming in at <3:08 and <1:25 consistently for my track workouts (800/400's respectively).

My PB for the half is 1:28


My 3:36 PB was 8 years ago and was of very little training, I had done a 70.3 two months prior, but leading up to that marathon I was likely averaging <30 mpw, no cross training. I was clueless about HR and MAF back then but knowing what I know now, most of my runs were all "tempo" style runs.

If you are running a 1:28 you are definitely under 3:30, more like 3:12 with good mileage. Definitely not sub 3 hour.

Couple of years ago I ran a 2:49 on 25-30 miles per week plus swim and bike volume. But as dcpinson pointed out in another marathon training discussion thread, I underperformed, as my 5k at the time was 16:52. And fair enough, he knows his stuff, the last 8 km were a struggle.

To do a solid open marathon to the best of your ability, you need the mileage. If you are not injury prone like me, I would just forget about swim-bike run training for a bit and just focus on building your mileage (~60 miles per week) for a few months training for your marathon race.

This is such an individual question that the answers won't help much.

I'm 85kg and run sub 2:50 open on about 30-40mpw, plus swimming/cycling. My PR in an IM is 3:07 with a 2 minute toilet stop.

Then you have people who run slower on more miles and faster on fewer miles. You just need to figure out what works for you.

I've run a few sub 3 marathons out of Ironman training. I'm 38 yo.
Best open marathon is around 2:47. I typically run an IM marathon under 3:10.

Because of that, if I'm fit, a sub3 marathon isn't a particularly big challenge. I've paced friends who wanted to go sub3.
But it still takes a while to recover from a marathon so I tend to do it far from triathlon races I care about.

Over a year my training volumes are around 13-15h week. Longest weeks get to around 20.
In terms of duration, 50% bike, 25% swim, 25% run.
I don't think I ever go above 50k running per week.

I've found that the more I cycle the faster I run. The more I run the more likely I am to get injured.
I am tempted to run more and see what I could do with more running volume but I'm quite risk averse with that.

Running is my best discipline of the three even though I don't really have a typical running body. I'm 1.75m tall and have a kayaking background so I carry extra weight with fairly broad shoulders and chest.

When I run, I run easy most of the time and prefer doing intensity on the bike. I see a lot of people crash and burn in running training - especially intervals, and I've been there too so I'm very conservative now.
My easy running pace goes from 5:20/5:30km when not very fit to breaking 4:50km when I'm very fit.
My long runs are rarely above 2h.

Course selection is key for a PB in a marathon. I can recommend Seville, Spain of all the places where I've run. Also, it helps to be in a good starting pen otherwise some big marathons are too crowded. London and Berlin can be too crowded if you're in the wrong pen.
A sub 3:30 pen would slow you down a lot in big races. If you can use a half marathon time to get into a good pen it would help a lot but it's not always accepted.

You've got 30 minutes to shave, it's a big jump. If you didn't have much aerobic training like you said maybe it's closer than you think.
I hope the above helps. Good luck!

If ur pb for the half is 1:28 I would suggest you focus on building ur running endurance to be able to carry that speed over the second half. Ur short term goal of first breaking 3:30 is a good one and then u can aim to reduce that further over the next couple of years to 3:20, 3:10, etc. Sometimes by focusing on building that endurance you can achieve a breakthrough and get there faster.

That said, don’t ignore upper body strength to help you carry that speed over the entire distance. If you swim, doing a 1500 yd swim once or twice a week will be sufficient. If not try to do weights a couple times a week. For your long runs, I always suggest breaking them up into two runs of a am run of 15 to 17 miles at a good pace with some half marathon speed built in followed by a pm run of 4 to six miles at marathon pace. Doing anything longer than a straight out 18+ miles is just going to lead to injury.

Bike an hour instead of run on your easy days to take the pounding off your legs so you are ready to absorb the running miles of 50 to 65 miles per week.

Good luck and let us know what worked for you.

Yeah that 1:28 is encouraging. Can take a shot at sub-3:10 off of that. Swap out (when you get into your marathon build) the 400s/800s for threshold work in the 1k-3k range. Build up your long runs & include marathon paced work in them.

Hopefully this is a qualified reply as I have just done exactly this and ran my first sub-3 (2.58) two weeks ago at the age of 41. My training is multisport for full distance and 70.3, but with a little more run focus in the last 3 months. A typical week has been 3x runs per week all winter (usually one steady 1hr, one either threshold or tempo intervals 1hr, one long up to 2.5hr), maximum run milage was a little over 60km in a week, usually around 50km. Also 3 bike sessions per week (1 endurance-tempo, one threshold and one long). But this is based on 4-5 years of consistent training and not a single winter's work. For reference I ran a high 1.22 half in November last year and my best IM marathon is a hilly 3.28, but hoping to improve on that.

I don't understand... If your goal is sub 3 and you have an extra x-number of hours to ride your bike, why do you only want to run 25-30 mpw? You'd get more bang for your buck into using that extra time spent easy running than you would by biking (again, assuming your goal is marathoning).

Typically speaking, if your goal is to be a good marathoner, then train for a marathon knowing that you won't be the best triathlete. If your goal is to be a good triathlete, then know you won't be the best marathoner. You can do these both well in the same calendar year but you focus on one, recover, then transition and focus on the other.

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Take a short break from ST and read my blog:
http://tri-banter.blogspot.com/

I ran my first marathon in '97 (Chicago; 3:10). After swearing that I'd never run another, I kept at it, increasing my mileage trying to BQ and then to break 3:00. Got up to 70+ mi/wk, added a track workout program, and chipped away some time towards that goal. Best time was 3:00:40 (in 2000). Got into tri around '99-'00 and started riding with a club (roadies) and tri training with a group of friends. My running volume dropped to 40-50 mi/wk, but my cycling went WAY up. Started training for IM, so putting in lots of steady tempo miles, plus interval workouts, hill repeats, etc. Running was 4-5X/week, including track workouts on Tuesday, long tempo+ intervals on Thursday, long run Sunday plus the occasional EZ run and/or brick workout. In 2001, I ran 2:56 (Chicago). Huge PR with less running mileage and lots of endurance riding.

YMMV, but more running volume is not always the answer.

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"The will to win means nothing without the will to prepare" - Juma Ikangaa

http://www.litespeed.com

As someone else pointed out, it all depends on where you come from, where you been. But from what you have said about yourself, certainly within reason to go under 3 with a bike and run plan. At your age I did this taking out 7 weeks of Tri training and just ran about 40mpw and did one longish ride for the endurance benefit per week. Ride was at or just above 3 hours and it was hardish(sorry, dont do zone stuff). Runs were all at race pace average, even the longer ones. You can get away with this if your are somewhat durable, and keep the weekly mileage at the low end of marathon training. So for your goal, about 6;51 pace as an average per run. Start out slower, and finish faster, easy peasy!!!

I suppose you could do a swim or two for recovery, but I chose not to overload too much, as the hard paces of the runs were enough for me. Did one really long run 4 weeks out(actually ran a training marathon) and that regime netted me my best ever stand alone. As a couple others have noted, maybe add in one more run and sub out a bike to get above that 30mpw, and perhaps up the intensity of it all since the mileages are low..

See how it goes, see how you adapt in the early weeks, and it good then keep going, if not then reevaluate and try something different. We all react different to training stimulus, but what you are attempting is certainly achievable if you find one that works for you..

I was "sure" I could do what you are hoping to do. I was running consistently in the 35-40 mpw range and mostly tri training. Age 38 I ran 3:08 and age 39 a 3:07 and both times I was on pace for most of the race and just ran out of gas (I'm sure I had a 3:03 or so in me had I just paced it right. I ran 20 miles at 6:50 before blowing up at age 38). After 2020 I realized, shoot, if I'm going to run sub 3 I kind of need to get it done because I was (then) 44. So leading into a marathon in January 2022 (almost 46) I did a 15 week block at an average of 55 mpw. I felt great and ran a 3:05. Did the same thing the next year and got sick and ran 3:10.

My opinion: if you want to run Sub 3, commit to running. There are some people who are a more talented than me who can certainly do sub 3 on Tri training, I was close but not quite that good. I regret not figuring this out when I was (probably) capable of running a sub 3.

Guy I know did sub 3 at Boston. Struggling with injury. Usually hard interval run then bike next day (not easy bike, but 1 hour on zwift) for weekdays. Weekend Saturday long run, then Sunday 100ish mile ride.

I myself started subbing in hard bikes for easy run days and it's been helping. Used to run 7 days a week, if anything mileage addiction slowed me down

I don't have any genetic predisposition for running. I ran my first marathon in 2014 in 4:06, and then two years later in 3:28.

My PB was in 2020 when I was 28 years old - 3:03 on a hilly marathon. I've checked Training Peaks - my weekly running mileage in the ten weeks leading was as follows: 31, 24, 29, 13, 28, 30, 25, 38, 29, 23.
I trained on the bike (both indoors/outdoors) for around 7-8 hours per week, and did some swimming too (not more than 4 miles total).
I know it would be very hard for me to run more (both mentally and physically, as it could lead to injuries) than 40 miles per week, so I prefer the cross-training approach.

This year I've been running no more than 27 miles per week and ran a half marathon in 1:25, which translates to a potential sub-3-hour marathon. Average bike is also 7 hours/week (with Z2 and quality Vo2 intervals)
I believe my running form is similar to that of 2020, or a bit better.

Thanks again for the insight everyone! You've all given me some great ideas to work with. I understand everyone is different and I am not looking for a definitive black and white formula. Curious to see what's worked for people.

For all of you who are confused why I don't aim for 70+ mile weeks of running, marcoviappiani summarized why in his reply...




My current limitations with running vol seem to be around 35mpw or ~5 hours/week before injuries creep in. I've been doing multisport (70.3's, half marathons and 2 full marathons) for 10+ years off and on, and despite building slow and respecting the "10% rule", I still seem to have issues with higher running vol.

I've been working with a PT/strength coach through Gait Happens and am looking forward to seeing future benefits. I've been doing 2x weekly strength sessions geared towards mitigating running injury and optimizing run form.

Thanks again!

I'm going to add one more thing related to finishing out that last 6-8 miles well. By the time you pass two hours, the liquid you drink and the 'food' you eat is going to start to matter more. I'm pretty good with any events below two hours and not good at all with events over two hours because I just don't digest food well at higher intensity. The longest mulit-sport event I've ever finished was around 5-5 1/2 hours. I dnf'ed both my attempts at the American Zofingen long course duathlon and gave up marathons and Half IMs. My only really good marathon and my only really good half IM were both on days were my body's stores of energy were really topped off and I felt phenominal. One was a 2:44 marathon and for the other I ran a 1:24 for the half marathon. I drank a little water for the marathon and for the half I probably had 40 oz of water and 2-300 calories.
I never eat food in traning and essential run and ride most everything in what people would call a fasted state in order to avoid stomach distress.
Over the last few years I've been experimenting with rice-based products that someone suggested after I melted down/had stomach distress in a 5-hour gravel race. So now I eat crunchy rice-cakes and rice crispie treats and it mostly agrees with my stomach. I used that plan to ride up Mauna Kea which, for me, is essentially a 7 hour climb from sea level to nearly 14.000 feet.

I'm not suggesting rice cakes so much as to find out what you can digest while running marathon pace and use it ALL THE TIME in training. I still have stomach meltdowns despite following a very meticulous plan, but they happen less often now. I think you will have a very hard time getting through the last 6-8 miles without eating something that you trained with for the duration.

Unless you have an iron stomach like my daughter, who could eat an entire meal at BJ's and then go bang out a 7:30 pace 10 mile run.

That's sounds like the much faster and better version of me! I'd say I run about 30-35 miles per week on average, and I knocked out an early season 2:36 this year. And just did a fun run through Boston in 2:48 while stopping at beer tents and high fiving every person who wanted one.

I bike a lot though, compared to most AGers at least. I think riding hard for 3-5 hours with a short-to-medium brick run once every weekend is the key addition to my running engine. I can get my HR pretty high and keep it there for a long time on the bike.

And my other 3-4 rides in the week are rarely easy. Lots of threshold and sweet spot work. Maybe one will be easier. Most of my milage on foot is a mid week 8-10 miler and the weekend long run. The rest is mostly speed and tempo work. I consider my walks to work and even my harder swims my "recovery" sessions.

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Too old to go pro but doing it anyway
http://instagram.com/tgarvey4

I overtrained without a healthy strength & mobility running foundation for a marathon a few years back. I had recurring Achilles issues and plantar fasciitis.

At the time I was also training for triathlons and 3mo prior to my marathon I couldn’t run whatsoever.

My typical training week was s/b/run and I replaced the runs with elliptical exercises. It made wonders for helping the running recovery, strengthen my glutes, and build my aerobic engine.

I eventually could run again (I was doing PT multiple times a week too) a month and a half before the marathon which allowed me to build into long runs again and did sub 3 at the marathon.

My big take away is that when injured for running, we can cross train with swim bike AND elliptical with good success.

Thanks for the insight!

It sounds like you're doing an LSD run AND a brick workout every weekend?

Can you define "sweet spot work"?

Appreciate it!

I've noticed a lot of the responses here violate the marathon training guidelines of "LSD = 30% of weekly mileage, speed/tempo = ~ 20%, etc" but I guess its ok if we're filling the aerobic bucket in other ways (eg. biking, swimming).