Competing With Your Younger Self

Emily Oster

9 min Read Emily Oster

Emily Oster

Competing With Your Younger Self

What running times can tell us about slowing down

Emily Oster

9 min Read

My family have always been runners.

My favorite picture of one of my younger brothers is when he’s perhaps 5 or 6, crossing the finish line of a race, stopping his watch. It’s not just that he was running races at this age, it’s that he was concerned about his time. This kind of slightly extreme attitude toward recreational running has had a hold over me, that brother, and my dad more or less since I can remember (my mom and the other brother were largely spared).

When I was a kid, I vividly remember Dad’s quest for the sub-3-hour marathon. He finally got it in the 1987 Philadelphia Marathon (2:58:45). It was the era before cellphones, so we didn’t find out until he got home, and I recall standing on the porch and just how happy he was.

We are all familiar with that chasing of the PR [personal record], of trying to hit some elusive round time goal. It’s easy to see the accomplishment there. But there is also the unfortunate reality that, as we age, it gets less realistic. At 42, I ran some PRs last year, but only because I moved to distances I hadn’t done before (the “auto-PR”). My dad is 80 now. He still runs most days, and is always trying to get faster, but the 3-hour marathon isn’t in reach.

What do we chase when we can’t chase the PR? One option is chasing other people — we can try to hit age-group wins and age-group times. But most of us aren’t winning age groups. And for many of us, the competition with ourselves has long been our main driving force. The question is: How can I compete with my younger self? How do I know if I’m outpacing her?

My dad, Ray Fair, asked the same question in the late 1980s, as he neared 50. In addition to sharing a love for running, he and I also share a love for data and a passionate belief that it can inform our lives in ways that other people might not expect. I’m an economist, and I have made a career of translating data into actionable insights for parents. My dad is also an economist, and while his focus is on more traditional economic topics (namely, the macroeconomy — he’s an economics professor at Yale), he could not avoid the temptation to use data to figure out where he stood relative to his past self.

In 1994, Dad published a paper in a reputable economics journal with the title “How Fast Do Old Men Slow Down?” The basic idea in the research is to ask, effectively, what the impacts of aging are at the upper limits of performance. A secondary use of this data is to translate it to our own running.

What the paper actually does is look at world records, by age, in various running events and fit-curves to them. To make this more concrete, I’ve pulled out the current single-year age records for men and women in the marathon in the graph below.

A chart from Emily Oster shows marathon record running times by age, with a sharp increase after age 70.

The graph suggests a particular shape to our age-based decline. First, performance is pretty flat up to age 40. There is then a pretty steady linear slowdown up until sometime in your 70s. After that, the decline begins to accelerate.

The analysis in the paper uses data like this to estimate (1) how slow the decline is in that first phase, after 40, (2) at what age the decline starts to accelerate, and (3) how fast it declines after that. From these numbers, it’s possible to calculate your own expected decline.

What the paper actually calculates is an expected percentage decline by age. What Dad ends up concluding is that your performance will decline by about 1% per year until age 77, and then much faster after that. This is an average that is pretty consistent across race distances. (Noting: For data limitation reasons, all the analysis is done on men. However, the graph above suggests that women look pretty similar.)

The result of all this is an expected percentage decline by year. We can then apply this to our own racing. If the world records represent the absolute minimum time by age, then the evolution across the records reflects the most optimistic view of how we can sustain our times. By applying this to ourselves, we can ask how much (or not!) we fall off this trend.

To give a more concrete example: Last year, I ran a half-marathon in 1:34:52. I was 42. This year, I’m 43. Based on last year’s time, I should be able to run 1:35:47 this year — that’s a bit of a slowdown. Anything faster than that, even if slower than 1:34:52, would be an “age-graded PR.”

In the space of a year or two, especially before that pivot around 77, this doesn’t make a huge difference. But the years do add up to mattering. Dad has all of his marathon times up on his website (of course), and he noted for me that his best corrected age time is at age 53, when he ran a 3:10 marathon. Based on age grading, his sub-3-hour performance was only his third-best effort.

Age-grading yourself in this way can make you feel better about your current performances. It also has the side effect of making you feel worse about your earlier ones. For example: Let’s say I am able to accomplish my goal of running 1:32:00 in my next half-marathon, at age 43. On one hand, I’ll feel great. On the other hand, this tells me that I could have run as fast as 1:31:06 last year, at 42. Not as great.

[Author’s note: After this piece was written, I did run a PR in the half, 1:30:52. What this tells me, heartbreakingly, is I could have run 1:29:57 at age 42. I missed my chance to go sub-1:30!]

The most complicated part of this analysis comes when we start to look at much older groups.

First problem: there just are not a lot of very, very old people running marathons. This is a problem for fitting the data. We can, perhaps, be reasonably confident about the decline between ages 40 and 50, when many people run competitively. But there are fewer people in their 80s running marathons at all, let alone for time. This is especially true for women — as Dad says in his paper, “More time is needed to build up a sample of old women running road races.”

The oldest age records also pose another conundrum. There are some extremely impressive times. Most notably, Ed Whitlock of Canada holds the records at ages 68, 69, 73, 74, 75, 76, 80, 81, 82, and 85. At 73, he ran 2:54:48. Using age grading, this would suggest Ed could have run a 2:05 marathon when he was 40. This would put him in the records in that age range too, but he is not anywhere to be seen. In fact, his fastest marathon ever was 2:31, at age 48. A very respectable time, but not close to a record.

What happened? Ed ran as a teenager but then he stopped, and he took it up again in his 40s. This leads to an interesting question: If he had been running all those years in between, would he have had the stamina (or the knees) to run under 4 hours at age 85? I’m not sure.

The advantage of the “world record” approach to the data is that we are really seeing the limits at each age. But the disadvantage is that we are not seeing the path of a single person, and it seems very plausible that the individuals who are performing well when they are old are different from those who perform well when they are younger. Not always true — [Olympian] Joan Benoit Samuelson is in there with the record for 53-year-olds — but often.

My dad said this slightly differently when we talked about it. This approach, he points out, assumes that, while people vary in their pace and capacity, their potential decline is similar to some biological minimum defined by elite runners. In his view, this is perhaps not unreasonable for younger people, but as we age, there is just more variation and a lot less data. That leaves open space for one unusual person to really drive the results. Ed Whitlock may be a good metric of our maximum biological capacity, but he also may not reflect a reasonable path. This is underscored, I think, by the fact that the records at older ages are very concentrated in a few individuals.

A final interesting question: These data are based on the past. In an era of super-shoes, of better understanding of the value of cross-training, of better fueling options — could we age more slowly in our running? In 50 years, when we do these same estimations, would we find that the decline starts later, or goes less quickly? Impossible to say; perhaps we will have to wait until [world-record holder Eliud] Kipchoge is 75 to find out if he can beat his predicted age-adjusted marathon time (2:50).

What about my 80-year-old dad? The race he has most consistently run is the Labor Day 20K in New Haven. It’s been going for 45 years; he missed only two instances. He’s got his list of times, along with four friends who have also completed the race nearly every year. As he says:

Even though my best time ever was 1:18:40, at age 43, my best age-corrected time according to the age factors used on this site was 1:20:30 at age 48. The predicted minimum times [in his list] use the 1:20:30 performance at age 48 as the base. As you can see, my races since age 62 have been way off the regression line. The fault, I fear, is not in the line but in myself. The results for four other people reported on this site suggest that the line is fine.

This is spoken like a true lover of evidence. He’s willing to defend the data, even if it throws his running under the bus.


As many of you know, I like to run. And my go-to running clothes, which you will see if you watch my sweaty morning Instagram stories, are from Tracksmith. A few months ago, Tracksmith asked if I’d write something about running and data for Meter Magazine. I wrote about my dad, about research, and about using data to compete with your past self. Tracksmith generously agreed to let me reprint the piece here!

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The AAP’s guidelines recommend sleeping in the same room as your baby “ideally for the first six months.” However, the risk of SIDS is dramatically lower after four months, and the evidence in favor of the protective effect of room sharing is quite weak (both overall and even more so after four months). There is also growing evidence that infants who sleep in their own room by four months sleep better at four months, better at nine months, and even better at 30 months.

With this in mind, it’s worth asking why this recommendation continues at all — or at least why the AAP doesn’t push it back to four months. They say decreased arousals from sleep are linked to SIDS, which could mean that babies sleeping in their own room is risky. But this link is extremely indirect, and they do not show direct evidence to support it.

According to the data we have, parents should sleep in the same room as a baby for as long as it works for them! Sharing a room with a child may have negative impacts on both child and adult sleep. We should give families more help in navigating these trade-offs and making the decisions that work best for them.

#emilyoster #parentdata #roomsharing #sids #parentingguide

The AAP’s guidelines recommend sleeping in the same room as your baby “ideally for the first six months.” However, the risk of SIDS is dramatically lower after four months, and the evidence in favor of the protective effect of room sharing is quite weak (both overall and even more so after four months). There is also growing evidence that infants who sleep in their own room by four months sleep better at four months, better at nine months, and even better at 30 months.

With this in mind, it’s worth asking why this recommendation continues at all — or at least why the AAP doesn’t push it back to four months. They say decreased arousals from sleep are linked to SIDS, which could mean that babies sleeping in their own room is risky. But this link is extremely indirect, and they do not show direct evidence to support it.

According to the data we have, parents should sleep in the same room as a baby for as long as it works for them! Sharing a room with a child may have negative impacts on both child and adult sleep. We should give families more help in navigating these trade-offs and making the decisions that work best for them.

#emilyoster #parentdata #roomsharing #sids #parentingguide
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It was an absolute pleasure to be featured on the @tamronhallshow! We talked about all things data-driven parenting and, in this clip, what I call the plague of secret parenting. To balance having a career and having a family, we can’t hide the fact that we’re parents. If mothers and fathers at the top can speak more openly about child-care obligations, it will help us all set a new precedent.

Watch the full segment at the link in my bio 🔗

#tamronhall #tamronhallshow #emilyoster #parentingsupport #workingparents

It was an absolute pleasure to be featured on the @tamronhallshow! We talked about all things data-driven parenting and, in this clip, what I call the plague of secret parenting. To balance having a career and having a family, we can’t hide the fact that we’re parents. If mothers and fathers at the top can speak more openly about child-care obligations, it will help us all set a new precedent.

Watch the full segment at the link in my bio 🔗

#tamronhall #tamronhallshow #emilyoster #parentingsupport #workingparents
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Invisible labor. It’s the work — in our households especially — that has to happen but that no one sees. It’s making the doctor’s appointment, ensuring birthday cards are purchased, remembering the milk.

My guest on this episode, @everodsky, has come up with a solution here, or at least a way for us to recognize the problem and make our own solutions. I’ve wanted to speak with Eve for ages, since I read her book Fair Play. We had a great conversation about the division of household labor, one I think you’ll get a lot out of!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#emilyoster #parentdata #parentdatapodcast #parentingpodcast #householdtips #fairplay #invisiblelabor

Invisible labor. It’s the work — in our households especially — that has to happen but that no one sees. It’s making the doctor’s appointment, ensuring birthday cards are purchased, remembering the milk.

My guest on this episode, @everodsky, has come up with a solution here, or at least a way for us to recognize the problem and make our own solutions. I’ve wanted to speak with Eve for ages, since I read her book Fair Play. We had a great conversation about the division of household labor, one I think you’ll get a lot out of!

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#emilyoster #parentdata #parentdatapodcast #parentingpodcast #householdtips #fairplay #invisiblelabor
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Prenatal vitamins 💊 If there is any product that seems designed to prey on our fears, it’s this one. You’re newly pregnant and you want to do it right. Everyone agrees you need prenatal vitamins, so you get them. But do you want to be that person who just… buys the generic prenatal vitamins?

Good news: fancier vitamins are not better.  Folic acid is the most important prenatal ingredient. Iron (with vitamin C) and DHA are also nice to have. Other included ingredients have only weak or no evidence to support their use. (If you do not consume animal products, add B12, plus a few others depending on your diet.)

Vitamins are just vitamins. Any prenatal vitamin that contains these is enough. 

Comment “Link” for a DM to an article with everything you need to know about prenatal vitamins.

#emilyoster #parentdata #prenatalvitamins #pregnancydiet #pregnancytips

Prenatal vitamins 💊 If there is any product that seems designed to prey on our fears, it’s this one. You’re newly pregnant and you want to do it right. Everyone agrees you need prenatal vitamins, so you get them. But do you want to be that person who just… buys the generic prenatal vitamins?

Good news: fancier vitamins are not better. Folic acid is the most important prenatal ingredient. Iron (with vitamin C) and DHA are also nice to have. Other included ingredients have only weak or no evidence to support their use. (If you do not consume animal products, add B12, plus a few others depending on your diet.)

Vitamins are just vitamins. Any prenatal vitamin that contains these is enough.

Comment “Link” for a DM to an article with everything you need to know about prenatal vitamins.

#emilyoster #parentdata #prenatalvitamins #pregnancydiet #pregnancytips
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When it comes to introducing your newborn to the world, timing matters. It’s a good idea to minimize germ exposure in the first 6-8 weeks; after that, it’s inevitable and, very likely, a good idea! This doesn’t mean you need to be trapped inside. The most significant exposure risks are from seeing other people at home — family, etc. These interactions are not infinitely risky, but they do pose more risk than a walk or a trip to the grocery store, since they involve closer interaction. Think simple and make sure everyone is washing their hands before holding the baby. 💛

#parentdata #emilyoster #newborncare #parentingadvice #parentingtips

When it comes to introducing your newborn to the world, timing matters. It’s a good idea to minimize germ exposure in the first 6-8 weeks; after that, it’s inevitable and, very likely, a good idea! This doesn’t mean you need to be trapped inside. The most significant exposure risks are from seeing other people at home — family, etc. These interactions are not infinitely risky, but they do pose more risk than a walk or a trip to the grocery store, since they involve closer interaction. Think simple and make sure everyone is washing their hands before holding the baby. 💛

#parentdata #emilyoster #newborncare #parentingadvice #parentingtips
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The first edition of Hot Flash is out now! Comment “Link” for a DM to learn more about the late-reproductive stage.

There are times when we expect hormonal shifts. Our reproductive lives are bookended by puberty and menopause. We discuss those changes often because they are definitive and dramatic — a first period is something many of us remember clearly. But between ages 13 and 53, our hormones are changing in more subtle ways. During the late-reproductive stage (in your 40s), you can expect a lot of changes in your menstrual cycle, including the length and symptoms you experience throughout. It’s an important time in our lives that is often overlooked!

🔥 Hot Flash from ParentData is a weekly newsletter on navigating your health and hormones in the post-reproductive years. Written by Dr. Gillian Goddard, Hot Flash provides all of the information you need to have a productive, evidence-based conversation about hormonal health with your doctor.

#emilyoster #parentdata #hotflash #perimenopause #womenshealth

The first edition of Hot Flash is out now! Comment “Link” for a DM to learn more about the late-reproductive stage.

There are times when we expect hormonal shifts. Our reproductive lives are bookended by puberty and menopause. We discuss those changes often because they are definitive and dramatic — a first period is something many of us remember clearly. But between ages 13 and 53, our hormones are changing in more subtle ways. During the late-reproductive stage (in your 40s), you can expect a lot of changes in your menstrual cycle, including the length and symptoms you experience throughout. It’s an important time in our lives that is often overlooked!

🔥 Hot Flash from ParentData is a weekly newsletter on navigating your health and hormones in the post-reproductive years. Written by Dr. Gillian Goddard, Hot Flash provides all of the information you need to have a productive, evidence-based conversation about hormonal health with your doctor.

#emilyoster #parentdata #hotflash #perimenopause #womenshealth
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There are plenty of reels telling you how to parent. Plenty of panic headlines saying that “studies show” what’s best for your kid. Even good data, from a trusted source, can send us into a spiral of comparison. But I want you to remember that no one knows your kid better than you. It’s important to absorb the research, but only you will know the approach that works best for you and your child. 💙

Now tell me in the comments: what’s a parenting move you’ve made recently that feels right to you?

#parentingcommunity #parentingsupport #parentingquotes #emilyoster #parentdata

There are plenty of reels telling you how to parent. Plenty of panic headlines saying that “studies show” what’s best for your kid. Even good data, from a trusted source, can send us into a spiral of comparison. But I want you to remember that no one knows your kid better than you. It’s important to absorb the research, but only you will know the approach that works best for you and your child. 💙

Now tell me in the comments: what’s a parenting move you’ve made recently that feels right to you?

#parentingcommunity #parentingsupport #parentingquotes #emilyoster #parentdata
...

Let’s talk about sex (after) baby! Today on the podcast, I was lucky enough to speak with @enagoski about her new book on sexual connection in long-term relationships. Especially after having kids, this is something many people struggle with. Emily tells us to stop worrying about what’s “normal” and focus on pleasure in its many forms.

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #parentdatapodcast #emilyoster #emilynagoski #comeasyouare #cometogether #longtermrelationship #intimacy #relationships

Let’s talk about sex (after) baby! Today on the podcast, I was lucky enough to speak with @enagoski about her new book on sexual connection in long-term relationships. Especially after having kids, this is something many people struggle with. Emily tells us to stop worrying about what’s “normal” and focus on pleasure in its many forms.

Listen and subscribe to ParentData with Emily Oster in your favorite podcast app 🎧

#parentdata #parentdatapodcast #emilyoster #emilynagoski #comeasyouare #cometogether #longtermrelationship #intimacy #relationships
...

Ever wondered if you can safely use leftover baby formula? 🍼 The CDC says to throw out unused formula immediately because of the risk of bacterial growth. However, research suggests that bacterial concentrations do not appreciably increase after 3, 12, or even 24 hours at refrigerator temperatures. Good news! This means there’s not a strong data-based reason to throw out formula right away if you store it in the fridge.

Comment “Link” for a DM to an article on another common formula question: should you throw away old formula powder?

#emilyoster #parentdata #babyformula #babyfeeding #parentingstruggles

Ever wondered if you can safely use leftover baby formula? 🍼 The CDC says to throw out unused formula immediately because of the risk of bacterial growth. However, research suggests that bacterial concentrations do not appreciably increase after 3, 12, or even 24 hours at refrigerator temperatures. Good news! This means there’s not a strong data-based reason to throw out formula right away if you store it in the fridge.

Comment “Link” for a DM to an article on another common formula question: should you throw away old formula powder?

#emilyoster #parentdata #babyformula #babyfeeding #parentingstruggles
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What’s the most important piece of advice for new parents? Here’s one answer, but I want to hear from you! Share your suggestions in the comments ⬇️

#emilyoster #parentdata #parentingtips #parentingadvice #newparents #parentingcommunity

What’s the most important piece of advice for new parents? Here’s one answer, but I want to hear from you! Share your suggestions in the comments ⬇️

#emilyoster #parentdata #parentingtips #parentingadvice #newparents #parentingcommunity
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What's in the bag of a Vagina Economist? 👀 Someone please tell me this looks familiar to you.

What`s in the bag of a Vagina Economist? 👀 Someone please tell me this looks familiar to you. ...

Comment ”link” for a DM to learn more about tongue ties 🔗

Breastfeeding is often difficult, especially at the start. For babies with tongue ties, many infants (and their moms) struggle to get the hang of a good latch. This can lead to painful nipples and to inefficient feeding, and then low weight gain.

So what does the data say about the increasingly common practice of cutting tongue-ties in infants to improve breastfeeding success? Several weeks ago, @nytimes published a long and quite scary article on this topic.

After diving into the data, here is what I found. There is limited evidence that frenotomy procedures improve breastfeeding efficacy and the harms of the procedure are minimal. Many women do report that it alleviates pain and helps them with breastfeeding. However, it should not be a first-line treatment for breastfeeding problems.

#parentdata #emilyoster #tonguetie #tonguetiebabies #breastfeedingsupport

Comment ”link” for a DM to learn more about tongue ties 🔗

Breastfeeding is often difficult, especially at the start. For babies with tongue ties, many infants (and their moms) struggle to get the hang of a good latch. This can lead to painful nipples and to inefficient feeding, and then low weight gain.

So what does the data say about the increasingly common practice of cutting tongue-ties in infants to improve breastfeeding success? Several weeks ago, @nytimes published a long and quite scary article on this topic.

After diving into the data, here is what I found. There is limited evidence that frenotomy procedures improve breastfeeding efficacy and the harms of the procedure are minimal. Many women do report that it alleviates pain and helps them with breastfeeding. However, it should not be a first-line treatment for breastfeeding problems.

#parentdata #emilyoster #tonguetie #tonguetiebabies #breastfeedingsupport
...

Tag a friend who needs to hear this 💛 For many choices in parenting, there is no one right answer. We can use research and data to make informed decisions, but ultimately, it won’t tell you what to do. Only you can decide what will be best for your kids and your family.

I’m here to remind you to take a deep breath and trust yourself. I’ll be here to support you along the way. 

Thank you to everyone who submitted videos, including:
@sarah.consoli
@jess_lynn627
@nicolevandenwills
@thedrblair
@ncbenedict29
@haleycimini
@iamkellysnodgrass
@calesse_smith
@garnet__gordon
@jencoopgaiser87
@danigirl18c
@jamielundergreen
@carly_comber
@thecelebratingmama
@emilyannbynum
@eeliz413

#emilyoster #parentdata #parentingadvice #parentingsupport #parentingquotes

Tag a friend who needs to hear this 💛 For many choices in parenting, there is no one right answer. We can use research and data to make informed decisions, but ultimately, it won’t tell you what to do. Only you can decide what will be best for your kids and your family.

I’m here to remind you to take a deep breath and trust yourself. I’ll be here to support you along the way.

Thank you to everyone who submitted videos, including:
@sarah.consoli
@jess_lynn627
@nicolevandenwills
@thedrblair
@ncbenedict29
@haleycimini
@iamkellysnodgrass
@calesse_smith
@garnet__gordon
@jencoopgaiser87
@danigirl18c
@jamielundergreen
@carly_comber
@thecelebratingmama
@emilyannbynum
@eeliz413

#emilyoster #parentdata #parentingadvice #parentingsupport #parentingquotes
...

Congratulations on making it through another year of panic headlines! We’ve had some doozies this year, like aspartame causing cancer and the perils of white noise, but these headlines are very often based on poor data. Correlation does not equal causation. There will certainly be more panic headlines in 2024, but ParentData is here to debunk them for you.

#emilyoster #parentdata #happynewyear2024 #panicheadline #datadriven

Congratulations on making it through another year of panic headlines! We’ve had some doozies this year, like aspartame causing cancer and the perils of white noise, but these headlines are very often based on poor data. Correlation does not equal causation. There will certainly be more panic headlines in 2024, but ParentData is here to debunk them for you.

#emilyoster #parentdata #happynewyear2024 #panicheadline #datadriven
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