
How to find your perfect running pace: a tool to reshape the face of pre-race analysis
Miles Weatherseed is an ex-international 1,500m runner and is currently studying towards a Masters in Mathematics at the University of Oxford. He has spent countless hours alongside Tim Beeson-Jones, a PhD student at Cambridge University, applying this experience towards developing the ultimate tool in race analysis for LetsDoThis.com.
Imagine if I told you that I knew what time you were going to run in your next race. What if I also claimed that I could provide you with the ideal splits for every section of that course, to maintain an even running economy? And what if, after all that, I told you that I could whack those splits onto your Garmin to give you real-time feedback throughout the race?
It sounds impossible, right? On the contrary — our new Race Pace Recommender tool can do all of this in just half the time it takes you to make a cup of tea.
Finishing Time Prediction
Predicting marathon times has long been a fiercely disputed topic in the political hotbed that is the world of endurance running. One of the earliest recognised efforts to predict times was by a man called Peter Riegel, who proposed that one might rescale another performance using the formula:

Here, k is a constant, usually between 1.03 and 1.10, depending on fitness level. For most people, k is around 1.07. However, this formula has been shown to fall apart when used on distances above half marathons. Riegel reckons I can run a 2:20 marathon, which — however flattering — is almost certainly not true!
“These variables will enable us to tailor predictions to every last bit of information we have about an athlete…”
This is presumably what spurred on a couple of researchers to study over 2,300 runners and use the resulting data to construct the Vickers-Vertosick formula, which combines average weekly mileage with historic race performances to produce a more accurate value of k.
Our pace recommender takes whatever information you give it and uses linear regression to calculate an estimate for your value of k in Riegel’sformula. We then apply Vickers-Vertosick to this k value to come up with your adapted (and hopefully accurate) k value. Finally, this is used to estimate your finishing time for whichever race you select.
Grade Adjustment
Every race has a Flat Equivalent Road Distance (FERD) associated with it. This FERD is discussed in more depth in a blog post by my colleague, Tim Beeson-Jones.

A script parses the selected race’s GPX file and the latitude-longitude pairs of coordinates are run through the Shuttle Radar Topography Mission (SRTM) database to return as accurate an elevation profile as possible (as elevation data from GPS satellites is often inaccurate). Distance between adjacent pairs is calculated using Vincenty’s iterative formula — developed to consider the ellipsoid shape of the earth, rather than the spherical assumption made by most other formulae.
The resulting product is a sequence of tiny approximately 10 metre sections, all paired with a straight line distance and an FERD. The whole race’s FERD is then summed up and your predicted finishing time is then used to produce a target pace for each kilometre of the race.
For example, if I’d planned to take part in the Maverick Lancashire races a fortnight ago and had been in 14:30, 30:20 and 68:30 shape for 5k, 10k and HM respectively, the Race Pace Recommender would have advised me to complete the Middle race in the splits below:

Note: there is not a perfect correlation between the Elevation column and the pace. This is because a kilometre section may well start and end at the same height above sea level, but during that kilometre you could well be going up and down, again and again and again…
Garmin Compatability
This analysis would be utterly useless without a practical application, which is precisely why we have also developed an extension for Google Chrome. The automated response email has a JSON attached, which can be inserted into the Let’s Do This Race Pace Recommender extension. Your splits will then be used to create a workout on Garmin Connect. This workout can be sent straight to your watch, to keep you running with perfect running economy throughout your next race, regardless of how undulating it is.
This extension was written in JavaScript and should work well. However, Garmin Connect restricts the length of every custom workout to 50 “blocks”. This means that, if your race is above 50km, we have to give you a target pace to hit every 2km, which obviously restricts the resolution of our analysis. Hopefully, we’ll be able to get around this shortly.
The Whole Process
- Fill out the form at as accurately as possible
- Receive the automated response email. Download the JSON from this
- Download the Let’s Do This Race Pace Recommender extension
- Upload the JSON to this…
- Smash your next race!
Looking Ahead…
Currently, the whole tool is still in beta and bugs are inevitably going to emerge here and there. We intend to carefully review the formula used to estimate race predictions in light of more data once lots of runners have used the tool.
Certainly, further down the line the plan is to adopt more of a “machine learning” style approach to the whole thing, iteratively updating our pace predictions using an ever-growing data set. Furthermore, in light of research carried out by Dr Fokas (of Cambridge University) and Tim Beeson-Jones, we are also close to using a wider range of variables as inputs for our predictor. These will be incorporated and a PCA (Principal Component Analysis) approach will enable us to tailor predictions to every last bit of information we have about an athlete.
We would really appreciate any opinions and feedback, both on the experience of using the tool and on the theory underlying the whole thing. Please direct all such correspondence to splits@letsdothis.com.
Miles Weatherseed, 6/9/17
Sources:
1 “Pace and critical gradient for hill runners: an analysis of race records” (2012)https://dspace.lboro.ac.uk/dspace-jspui/bitstream/2134/16478/1/PaceCG_published.pdf
2 “An empirical study of race times in recreational endurance runners” (2016) https://bmcsportsscimedrehabil.biomedcentral.com/articles/10.1186/s13102-016-0052-y
3 “Direct and indirect solutions of geodesics on the ellipsoid with application of nested equations” (1975) https://www.ngs.noaa.gov/PUBS_LIB/inverse.pdf
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As the clock strikes midnight and the promise of a fresh start begins, many of us are setting our sights on challenges that will make 2025 a year to remember. To help give you some new year inspo, we asked our team to share their goals for the year ahead. Whether you’re looking to smash a personal best, conquer an iconic event, or try something entirely new, we hope our team’s resolutions inspire you to set some big, bold goals of your own.Here’s what we’re working towards in 2025:
New Year, New Goals: 2025 inspo from the Let’s Do This team
As the clock strikes midnight and the promise of a fresh start begins, many of us are setting our sights on challenges that will make 2025 a year to remember. To help give you some new year inspo, we asked our team to share their goals for the year ahead. Whether you’re looking to smash a personal best, conquer an iconic event, or try something entirely new, we hope our team’s resolutions inspire you to set some big, bold goals of your own.
Here’s what we’re working towards in 2025:

Reece: A Year of Firsts
"2025 is going to be a year of firsts for me. I’ll be tackling my first triathlon at Blenheim, running my first ultra at Race to the Stones, and (if I can snag a spot) taking on my first Hyrox event in London. Here’s to pushing boundaries!"
Book now:
Oscar: Chasing Speed
I’m keeping it short and speedy this year—hopefully! My goals are a sub-17-minute 5k and a 5-minute mile.
I’ve got my eye on the Battersea Chase the Sun/Moon events because the flat, fast course is perfect for a PB.
Book now:
Battersea Chase the Moon January

Lisa: Hitting the Trails and City Breaks
"I’ve heard so many great things about Maverick events from the Let’s Do This team, so I’m thinking of booking the Original West Sussex—it’s just a short train ride from London. I also want to use races as an excuse to travel, and I’ve got my eye on the Rome Marathon in March as my first running holiday of the year."
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Dom: Fast and Far
My focus is on speed and endurance. I’m aiming for a sub-1:20 half marathon at the Bath Half in March, then finishing the year strong at the Chicago Marathon.
Book now:

Rob: Epic Adventures
This year, I’m taking on the Ultra Trail Snowdonia 50k and aiming for the UTMB. If that doesn’t work out, I’ll swap the running shoes for a multi-day gravel race. Either way, it’s going to be an adventure!
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James: My First Ultra
This is the year I’ll tackle my first ultra! I’m heading up to the Lakes for the 55km 5 Valleys race in September. Can’t wait to take in the incredible scenery while pushing myself to new limits.
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13 Valleys Ultra Marathon (5 Valleys 50k)

Rachel: Elevating My Goals
"I’m mixing things up in 2025 by focusing on elevation rather than distance. My big goal? A race with 950 meters of climb over 16 kilometers. It’s going to be a whole new kind of challenge!"
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JC: A Year of the Super Halfs
I’ve convinced my friends to tackle the Super Halfs series with me. After running Copenhagen last year, we’ve got Lisbon on the cards for March. I’m also hoping to get into cycling—fingers crossed I can bag a spot at Bike New York's 5 Boro Bike Tour and combine it with a New York city break with friends!
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Whether you're gearing up for your first race or taking on a bucket-list event, there’s no better time than the new year to start planning your next adventure. What goals are you setting for 2025? Let us know—we’d love to cheer you on!

How To: Set Your 2025 Running Goals with Coopah
As we are approaching the end of the year, now is the perfect time to start thinking about your 2025 running goals, and what you want to achieve over the next 12 months.We know it can be hard to know how to set your running goals, so we have asked Jordan Foster, Head Coach at Coopah, the Run Coaching App to share her top tips.
As we are approaching the end of the year, now is the perfect time to start thinking about your 2025 running goals, and what you want to achieve over the next 12 months.
We know it can be hard to know how to set your running goals, so we have asked Jordan Foster, Head Coach at Coopah, the Run Coaching App to share her top tips.

I honestly love nothing more than sitting down at the end of December and writing a list of what I want to achieve the following year; whether that's running, professional or just general day to day life. But, for the purpose of this blog, let's stick to running.
And do you know the best thing about running goals: your goals are entirely your own.
- If you want to just start your running journey, amazing.
- If you’re chasing a personal best (PB), go for it.
- If you’re aiming to cross the finish line of your first marathon in one piece, incredible.
The exact goal itself doesn’t matter as much as the process of setting it, and building the plan to achieve it. So, here are some tips to help you create meaningful and achievable running goals for 2025.

Be Specific
Think about what really matters to you, as I said a goal doesn’t always need to be time based, but having a clear, specific goal is a great way to not only stay motivated, but also to ensure you are doing the right things to help you get there. For example a vague goal like “start running more” is a good start, but the magic really happens when you get specific and know exactly what you are aiming for;
- Want to aim for your first 5km? Awesome, set yourself a target date of when you want to achieve it to give you something to aim for.
- Running your first marathon? Brilliant, maybe the goal is to finish strong and soak in every moment.
- Just want to build confidence and consistency? Great, focus on nailing your training plan.
How Coopah Can Help: When setting up your training plan we will ask for your goal for your event, along with finding out more about your running history and experience. Which in turn will generate you a personalised training plan that is tailored specifically to your current fitness level and your overall goal. So you have peace of mind knowing that your plan is designed with your end goal in mind. Download the app and get started today.

Be Brave
Let’s be honest: big goals can feel scary. But does that mean we shouldn’t set them? Absolutely not.
Over the years, I have set myself many big goals in running. Some of these I have achieved, and some I have not. But does that mean I have failed? Personally, I don’t think so.
Because I still put myself out there, I still worked hard towards trying to achieve it and I showed up and tried my best. And that is really the most important thing.
So set those big goals. Be brave and push yourself. And remember, the best growth happens when we take on those big challenges that feel slightly out of reach.
How Coopah Can Help: Having the right support can make all the difference when setting those big goals, and with Coopah you have 24/7 access to our team of coaches who are on hand to help, support and advise you throughout your training plan. Whether you have a question about your plan, need that extra bit of motivation or just want to share how you are getting on, we are there for you every step of the way. Download the app and chat to your coach today.

Be Realistic
That said, whilst being brave is great, it’s also important to be honest with yourself and make sure those goals you are setting are realistic in the time frame you have;
- How far away is your event?
- How much time can you realistically commit to training each week?
- What’s your current fitness level?
For example if your dream is to run a marathon, but right now you are right at the start of your running journey, you may just need to take a step back and set yourself a smaller goal to achieve in the short term, whilst creating a long term plan to achieve this.
By setting yourself smaller, manageable goals this will also help to keep you motivated during your training as you will hopefully see progress a lot quicker, whilst knowing everything you are doing is getting you one step closer to achieving your ultimate goal.
For example your first goal could be to run your first 5km, then build up to 10km and so on.
Remember, progress in running takes time. It takes effort, hard work and commitment. We can’t always achieve everything we want to do at once, so having those long term goals and plan is a great way to keep you motivated to ensure you are always heading in the right direction.
How Coopah Can Help: With Coopah you can easily track your progress to see if you are on track to hitting your goals. Every workout will be tailored to your overall goal so you can see in real time if you are hitting your target. Download the app and start making progress from today.

Be Prepared
So here is your challenge for this week. Take some time to sit down, grab a notebook, or even the notes app on your phone, and think about your running goals. Not just the easy ones, but those big, bold, slightly scary goals too. Write them down.
Now, once you’ve got those goals in front of you, I want you to think about how you’re going to achieve them, and use the tips from this blog:
- Be Specific about what you want.
- Be Brave and aim high.
- Be Realistic about your current fitness and life commitments.
I promise you, just writing your goals down is a huge step forward. Once you’ve committed to them, you’re already on the journey. And remember, the journey itself is part of the fun.
You might hit your goal in 3 months, or 6 months, or it could be a long-term goal that takes a few years. Whatever the timeline, every time you lace up your shoes and head out the door, you’re one step closer.
So next time you’re on a run, remind yourself: every mile, every sweaty workout, every “I really don’t feel like this” moment is part of the process. Celebrate the little wins along the way, as they’re what make the big wins possible.
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The Challenges Women Face in Running and How It Impacts Participation
Running is often lauded as one of the most accessible sports—just lace up your trainers and go. However, for many women, the barriers to participation go far beyond the logistical. While safety concerns are frequently highlighted, deeper systemic issues like access to the sport and unequal treatment are also preventing more women from running. It was a topic keenly discussed at our In Her Stride panel held at the end of November, with key members of the female running community including Sophie Power, Tasha Thompson, Rehana Mawani and Emily Shane.
Running is often lauded as one of the most accessible sports—just lace up your trainers and go. However, for many women, the barriers to participation go far beyond the logistical. While safety concerns are frequently highlighted, deeper systemic issues like access to the sport and unequal treatment are also preventing more women from running. It was a topic keenly discussed at our In Her Stride panel held at the end of November, with key members of the female running community including Sophie Power, Tasha Thompson, Rehana Mawani and Emily Shane.
Before we kick things off however, we should highlight that female participation in running events is growing, and this is a great thing! According to data from Let’s Do This, women in their 20s are the fastest-growing demographic in event participation this year. However despite this, women are still 16% less likely to run every week compared to men. This disparity is particularly striking given that women report higher levels of personal benefits from running, such as improved fitness, better sleep, and reduced stress.
The reasons for this are complex and personal, however we have broken down three key challenges discussed during our panel and the solutions explored that could help address them.
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1. The Pressure of Pace
One of the biggest hurdles for many women is the pressure to run faster. Despite the average UK woman’s running speed of 06:37 min/km (according to Strava), most run clubs don’t cater to this with the slowest pace often around 6 minutes per km. Add to this the relentless focus on personal bests and fast times on social media, and it’s no surprise that many women feel too intimidated to join in.
Thankfully, there are starting to be more people rebelling against this speed obsession, including our panelist, Emily Shane. Emily has been leading the charge to encourage more women to disregard pace and focus on the experience of running to drive uptake amongst women. Initiatives like events without cutoff times and more inclusive pace groups at running clubs are vital to creating a more welcoming environment and broadening the benefits of running to the experience and community.
2. Perception of Sport in Schools
One of the topics hotly discussed was how for many girls, the barriers to enjoying physical activity start at school. Puberty, coupled with changing bodies and fluctuating emotions, can make sports feel daunting and uncomfortable for teenage girls. Research highlights this disparity: only 38% of girls enjoy sport and exercise compared to 53% of boys, and just 26% of girls feel confident in physical activity versus 43% of boys.
The panel emphasised the need to address this such as:
- Introducing a wider variety of sports and fitness activities to cater to different interests
- Providing more supportive and confidence-boosting PE kits.
- Showcasing more female role models in sport to inspire young girls.
By addressing these issues at the school level, we can foster a love of sport that lasts into adulthood.
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3. Treatment at Events
This is a topic that panelist Sophie Power, founder of SheRACES is incredibly knowledgeable and passionate about. Even at organised running events, women often experience unequal treatment. From “unisex: t-shirts (which are actually designed for men) to a lack of sanitary products in portaloos, these "small things" can collectively make women feel like an afterthought. Prize money inequality and rigid event policies—like no deferral options for pregnant or postpartum women—further highlight these disparities.
Thankfully, initiatives like the 50:50 campaign by Threshold (a campaign to get 50% of women at Ultra startlines vs. the current average of 30%) and the advocacy work of SheRACES are driving change, and there are many amazing event organisers such as Maverick, Threshold, Why We Run and many more, that are working hard to make their events are inclusive as possible for women.
Despite these challenges, the panel and attendees felt overwhelmingly optimistic about the future of running for women and the benefits it brings us. Progress is being made, however we all need to add our voices to the conversation to help more women get into the sport and reap the benefits.
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Some Helpful Resources
Here are a few helpful resources. This list isn’t exhaustive by any means, however is a good starting point for those looking for inspiration on where to start.
Female friendly events:
- Threshold Events
- London Landmarks Half Marathon
- Maverick Events
- Why We Run
- Women Run Series London 2025
Female Only Run Clubs
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