Long Run vs Marathon pace

[u/guy-fierii]

My first marathon is Chicago in about 6 weeks. This is my first marathon training cycle, and I’ve been running my double-digit long runs around 13:30–13:45/mi, intentionally keeping them very easy since these distances are new to me.

My shorter easy runs (4–6 miles) naturally fall around 11:30–12:30/mi, and I could push those closer to 11:00 if I wanted, but speed hasn’t really been my focus during this training block.

My most recent long run was 15.5 miles at about 13:45 pace, and I still had enough left to run the final 2 miles around 12:00/mi. I’m also training through the summer in Hawaii, so most of my long runs have been in pretty significant heat/humidity, while the race will be in Chicago in October.

For other first-time marathoners: how closely did your race pace end up matching your long-run pace? Should I realistically expect ~13:45/mi on race day, or is it reasonable to expect that I could run somewhat faster with a taper, race-day conditions, and cooler weather?

I’m not trying to force a specific time goal. I’m mostly trying to figure out what a realistic starting pace should be so I don’t go out too fast. TYIA!

[u/MileHighManBearPig]

Just commenting because I’m a first timer too and these are basically my numbers as well.

I just want to finish. Then sub-6 if possible. Near 5:30 would be ideal.

With cooler fall temps and a taper I’m hoping to do 12:40 ish pace which is pretty natural for me and easy. IDK.

I ran a half in about 2:25 earlier this spring.

[u/Greenie3226 → u/MileHighManBearPig]

Rule of thumb is to double your half and add 15 minutes. Or use VDOT calculator. Granted it’s your first marathon and so any expectations are ambitious, but at least that way you can get paces for easy/speed runs.

[u/MileHighManBearPig → u/Greenie3226]

That would put me at like a 5:15 ish marathon. I’d be stoked on that. I’m really just trying to finish tbh.

That’s a 12 minute mile and while I can do that for 13 miles pretty consistently, I have been running my long runs at closer to 13-13:30 in the summer.

[u/Arkele → u/MileHighManBearPig]

The summer heat murders your pace

[u/Kyoma94 → u/Greenie3226]

I’m somewhat surprised when someone says ‘expectations for your first are ambitious’. Someone could be training for 7 months straight dilligently 4 runs 5-6h per week just to hear that.

And its not to harp on the comment I’m just surprised

[u/Greenie3226 → u/Kyoma94]

I say that as someone who ran his first marathon last year: the calculators predicted I would run 4:50, and ended up doing 5:20 in New York (hit the wall, started out too fast, used the bathroom). It’s a big feat to run a marathon at all, just don’t think it’s helpful to go out with a goal time the first time. Enjoy the experience more than anything is the best advice.

I’ll chase the goal this November again for marathon #2!

[u/Procrastinator1971 → u/Greenie3226]

Adding 15 minutes is not enough at these speeds. A better rule of thumb is to multiply the half by 2.22.

[u/Sea_Aside9658]

Chicago is my first marathon this year too! My coaches keep saying I’ll see a drop in pace on race day and to trust the process..we’ll see 😂

Personally I’m planning to go out pretty easy. I always run by feel and not watch pace so hoping the weather cooperates and the taper does its thing. I have no time goal and have been training 10:30-11 pace.

Also idk how the terrain is where you’ve been training, but Chicago is relatively flat, so that might give you a boost as well if you’ve been on hillier routes.

Also as a local, I hope you enjoy the city :)

[u/RTRoar → u/Sea_Aside9658]

Everything will be a bit easier on race day. Tapered, energy, adrenaline, the crowd of runners pushing with you.

The key is not to mistake this for all the sudden I’m a super runner and should go out at this pipe dream speed I can’t possibly hold. That’s where I’ve seen people get in trouble.

[u/Sea_Aside9658 → u/RTRoar]

Great point! Def did that during my half this year 😂 just need to figure out how to stay grounded on race day!

[u/Castcore → u/Sea_Aside9658]

I'm not qualified to say this but I'm pretty sure it's good advice if you're not planning on running to a watch pace. Set yourself a maximum pace limit and check your watch to make sure you stick underneath it out of the gate for the first couple kms/miles until you get into the drone of things. Stop yourself from going out too hard with the excitement and being punished for it later. You can always speed up later, but you can't undo the start of your race.

[u/cj_daking]

I've run Chicago 6x - great race! I'd set your pace at about 60 seconds faster than your average long run pace. Try to run an even split or even shave a bit off the second half but not much. You're going to have such a good time. One of the best finish lines in America - maybe second only to Boston or NY. My one recommendation for Chicago is to bring earplugs. Traffic downtown at night is loud and echoes like nobody's business. Have fun!

[u/guy-fierii → u/cj_daking]

I’m so excited! Thank you for your advice 🙏

[u/Real-Contribution285]

Unsolicited advice: Just get your ego out of this (what I needed to hear). You’ll run more marathons soon enough. You’re there to enjoy yourself. Don’t start too fast. Enjoy the flow of running with others. I felt great at times after 17 miles because I knew I had this. I’m excited for you!

[u/guy-fierii → u/Real-Contribution285]

So real. My original goal was 5 hours HA HA ! I just assumed because I could run shorter distances comfortably at 11:30, I could slowly increase the mileage at the same pace.. was I incorrect omg.

I’m already looking at signing up for another in 2027. I used Garmin for this marathon block and I feel like it didn’t have me do far enough long runs. I reached out to my “coach” (I’m running with a charity) and he basically gave me distances to do on Saturdays while still keeping with the Garmin training during the week.

In the future I would definitely do way more strength training & a structured plan like Higdon! So this one I’m just going to enjoy it, and remind myself I did this for charity not for my ego!

[u/cocker_daniel]

Commenting because I’m taking the same approach for Chicago and am curious to hear what others say. Good luck, see you at the starting line! 🫡

[u/guy-fierii → u/cocker_daniel]

Slay! See you there

[u/urastarbaby]

I have similar, maybe slightly slower, training stats to you and ran my first marathon at an average 13:13 pace. I bet you could expect to run your marathon closer to a 13min/ mile or even quicker pace.

[u/BHWonFIRE]

My paces are very similar to yours. They say take your most recent HM multiplied by 2 and add in 20 minutes. Since you do not have an HM to base your marathon time, you can choose to go 60 seconds faster than your easy long run pace and try negative splits if you’re feeling good at halfway point. Based on my paces, my strategy is to go for a 5:10 marathon and try for even splits of 11:49.

[u/mommy_dearest]

I just ran my first marathon. My time ended up being my half PR from May x2 plus 15 mins almost exactly on the dot. I was nowhere near that pace on my long runs in the training block and thought I would be at least 15-30 minutes slower. Carb loading, the taper, race day energy, and cooler temps can take you a long way!

[u/afwaller]

In general your race should be faster than your long run pace.

Sometimes if people are undertrained this can't happen.

[u/HollisFaith83]

No advice to provide on your pace, but as a Chicago local, I just want to say that it’s Chicago and even though it’ll be oct don’t expect it to be cool out. There have been plenty of years that it’s still in the 80’s and humid/muggy out so all of your training will come in handy!!

Best of luck and enjoy!!!!

[u/ColadaMD]

Do you have a recent half marathon race? That would probably be best for seeing where you’re at

[u/guy-fierii → u/ColadaMD]

I do not 🙃 the most recent half marathon was back in April & I ran it at 13:45 pace, but it also went up/down diamond head crater the last 5k. I ended the race very disappointed because I had “more gas in the tank” but I conserved too much bc I knew it ended in steep elevation.

[u/Dull_Vast_5570]

The best way to estimate your potential pace is by actually all-out racing a short distance. Since you've been doing lots of mileage in your long runs, your endurance is high and so is your aerobic capacity. Therefore, if you can race 5km all-out and you enter the resuly into a VDot calculator, then it will give you a potential marathon finish time. If you only trained short distances for speed then it would be much less accurate.

Otherwise you can do an interval workout to estimate your potential. Look up the Yasso 800s workout. Those two methods will give you a strong estimate for your potential starting pace.

Otherwise, if you just want to finish and don't care about your time, just start at a really slow pace like you do in your 15 mile runs, and then pick up the pace if you feel okay after 20 miles.

Most newbies would benefit of racing 5ks, 10ks and then eventually half marathons for years before considering a full marathon.