Running Blog

Data for the informed and lifelong runner.

We dig into race data, training science, and the numbers behind marathon performance. From course analysis and BQ trends to pacing strategies and nutrition planning, these are the articles we wish existed when we started running. Pair them with our free running calculators to put the data to work.

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47 articles · updated September 3, 2026

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Data Studies (15)

Original analysis from race results, training logs, and finisher data — the research that makes 42Cal different.

Where Your Marathon Entry Fee Goes: What Races Spend
Where Your Marathon Entry Fee Goes: What Races Spend

The Boston Athletic Association pays elite runners more to show up than it spends on public safety and medical services combined. Appearance fees for a handful of professional athletes at the Boston…

Why Your Watch Says the Marathon Was Longer Than 26.2
Why Your Watch Says the Marathon Was Longer Than 26.2

Most runners who finish a marathon wearing a GPS watch seem to have run more than 26.2 miles. At the 2026 London Marathon, watches for 571 runners recorded a median distance of 42,722 meters against…

How Accurate Is the Riegel Formula for Marathon Times?
How Accurate Is the Riegel Formula for Marathon Times?

One in every ten runners using the Riegel formula to calculate their race finish times will finish more than 30 minutes and 24 seconds slower than they should. That formula is the equation behind…

Marathon Cut-Off Times: What Happens If You're Too Slow
Marathon Cut-Off Times: What Happens If You're Too Slow

In 1990, the year Carey Pinkowski became the Chicago Marathon's executive race director, six of the field's 6,168 finishers crossed the line after six hours, about one-tenth of one percent. By 2023…

How Marathon Pacers Work, and When to Run With One
How Marathon Pacers Work, and When to Run With One

New York Road Runners, the club that organizes the New York City Marathon, fields a roster of roughly 200 volunteer pacers a year, and about 90 of them work the TCS New York City Marathon each…

Why the Marathon Is 26.2 Miles and Not a Round Number
Why the Marathon Is 26.2 Miles and Not a Round Number

For 28 years, the Olympics could not settle on how far a marathon was. Athens in 1896 measured roughly 40 kilometers. Paris in 1900 came in at 40.26. London in 1908 ran 42.195, for reasons nobody had…

What Every Degree of Heat Costs Your Marathon Time
What Every Degree of Heat Costs Your Marathon Time

The 75th-percentile male marathon finisher, the runner who crosses the line behind three-quarters of the field, runs about 12 minutes slower at 17.4°C than he does at his own best temperature, ten…

Your Real Odds in Every World Marathon Major Ballot
Your Real Odds in Every World Marathon Major Ballot

In the closing weeks of 2025, 1,133,813 people entered the ballot for the 2026 TCS London Marathon, the random draw that decides who gets one of the race's public entry places, and fewer than 20,000…

What Altitude Costs You: Mexico City, Bogota, Denver
What Altitude Costs You: Mexico City, Bogota, Denver

Take eight elite cyclists up to 2,340 meters and test them on their first day there. Their VO2max, the most oxygen their body can actually use during hard exercise, drops about 13 percent. Their…

Why Boston Marathon Qualifying Cut-Offs Are Hard to Predict
Why Boston Marathon Qualifying Cut-Offs Are Hard to Predict

In 2021, running a Boston qualifying time was not enough. You needed to beat it by 7 minutes and 47 seconds. In 2022 and 2023, hitting the standard by a single second got you in. Two years later, in…

Sub-3 Hour Marathon in 2026: Demographics, Course Rankings, and Training Data
Sub-3 Hour Marathon in 2026: Demographics, Course Rankings, and Training Data

The sub-3 hour marathon sits at an odd intersection. It's one number. Three hours. And yet it separates roughly 97% of all marathon finishers from the other 3%. That gap is both smaller and larger…

First-Timer's Marathon Mistake Catalog: 50,000 Reports
First-Timer's Marathon Mistake Catalog: 50,000 Reports

Every marathon finish line tells two stories. The first is the official race report, posted with pride in running forums and shared on social media. The second, whispered between runners over…

Running Tourism Economics: How Marathons Transform Cities
Running Tourism Economics: How Marathons Transform Cities

The economics of running tourism tell a story that municipal planners and race directors have learned to read with increasing precision. Small cities across the globe have discovered that hosting a…

Marathon Elevation Profiles: When Hills Help or Don't
Marathon Elevation Profiles: When Hills Help or Don't

Marathon elevation profiles tell stories that finish times alone never could. A 3:45 finish on a rolling course means something entirely different than the same time on a pancake-flat route.…

What the data of over 100,000 runners teaches us about marathon times and training volume
What the data of over 100,000 runners teaches us about marathon times and training volume

Can you run too many miles when training for a marathon? Possibly. The data shows that runners who log more weekly mileage finish faster. Though it's not quite as simple. This post is for the…

Race Guides (15)

First-hand course intelligence: elevation, weather, logistics, and what to expect at races worth traveling for.

New York City Marathon 2026: The Six Hours Before the Start
New York City Marathon 2026: The Six Hours Before the Start

The New York City Marathon runs in five waves. A Wave 5 bus rider can spend close to four hours standing at Fort Wadsworth, the Staten Island staging ground where every runner gathers before the…

Paris Marathon qualifications: what gets you in
Paris Marathon qualifications: what gets you in

The 2026 Sports Rules and General Terms of Sale that govern the Schneider Electric Marathon de Paris list only two conditions for entry, in the paragraph that decides who gets to run: a minimum age…

Chicago Marathon 2026: What Flat Won't Save You From
Chicago Marathon 2026: What Flat Won't Save You From

The Bank of America Chicago Marathon climbs 243 feet over its 26.2-mile loop and descends 242 feet. Among the World Marathon Majors, the six-race series that also includes Boston, London, Berlin…

Berlin Marathon 2026: The Complete First-Timer Guide
Berlin Marathon 2026: The Complete First-Timer Guide

No course in modern marathon history has produced more world records than Berlin's. Between 1998 and 2022, men racing the BMW Berlin Marathon, one of the Abbott World Marathon Majors that make up the…

What Nobody Tells You Before Your First London Marathon
What Nobody Tells You Before Your First London Marathon

The email landed sometime in June. You got in, screamed, maybe cried, probably told everyone within earshot. That was Seven months ago. Now it's late February, you have eight weeks left until April…

Cape Town Marathon: Running Between Two Oceans
Cape Town Marathon: Running Between Two Oceans

The morning air carries salt from two different oceans. Table Mountain looms above, its flat summit catching the first light. You're standing at the start of what will become Africa's first Abbott…

The Best Races in Mexico: Live your Mexican Adventure
The Best Races in Mexico: Live your Mexican Adventure

Mexico offers runners something rare: world-class race organization, electric crowd support, and costs that make North American and European runners do a double-take. The country's race calendar…

The Great Ocean Road Marathon: Running Australia's Most Scenic Coast
The Great Ocean Road Marathon: Running Australia's Most Scenic Coast

The morning air in Lorne is cool and salt-tinged. Runners gather at the Surf Lifesaving Club Car Park, stretching beneath eucalyptus trees while the Southern Ocean rolls and crashes just meters away.…

Dubai Marathon: Chasing Fast Times Under Desert Stars
Dubai Marathon: Chasing Fast Times Under Desert Stars

It's 6:30 AM on a January morning in Dubai, and the air along Umm Suqeim Road hums with quiet anticipation. The sky shifts from indigo to soft pink, and there, silhouetted against the dawn, stands…

Valencia Marathon: Spain's Speed Factory for Personal Bests
Valencia Marathon: Spain's Speed Factory for Personal Bests

It's 8 AM on a December morning in Valencia, and the air hums with a particular energy. Runners from 80 countries stretch along wide avenues near the futuristic City of Arts and Sciences, their…

Ljubljana Marathon: Slovenia's Charming Autumn Classic
Ljubljana Marathon: Slovenia's Charming Autumn Classic

The morning light filters through the trees along the Ljubljanica River, casting golden reflections on water that has flowed through this city for millennia. Runners gather in the shadow of Ljubljana…

Athens Marathon: Running Where It All Began
Athens Marathon: Running Where It All Began

It's 9 AM in the small town of Marathon, Greece, and you're standing beneath the Tumulus—the burial mound where 192 Athenian warriors fell fighting the Persians in 490 BC. Around you, thousands of…

Running Japan: Tokyo Marathon & Beyond
Running Japan: Tokyo Marathon & Beyond

It's 7 AM in Shinjuku, and I'm standing among 38,000 runners at the Tokyo Marathon start line, but what strikes me isn't the massive crowd—it's the silence. In a country where queuing is an art form…

Discovering the Maratona di Ravenna
Discovering the Maratona di Ravenna

It's 6 AM in Ravenna, and the air is thick with anticipation and the scent of the Adriatic. I find myself stretching under an ancient archway, its bricks glowing in the early light. A friendly local…

A different kind of marathon: Marathon des Châteaux du Médoc
A different kind of marathon: Marathon des Châteaux du Médoc

Running marathons isn't typically associated with indulgence, elegance, or Bacchanalian delight. But the Marathon des Châteaux du Médoc isn't your typical marathon. Scheduled for September 6, 2025…

Training (7)

Plans, pacing, fueling, and the science of getting to the start line fit and fresh.

Marathon Training Plans Compared: Beginner to Advanced
Marathon Training Plans Compared: Beginner to Advanced

Hal Higdon publishes six free marathon training plans, and the hardest one asks for exactly the same longest run as the gentlest: 20 miles. Advanced 2 expects six running days a week and three hard…

The Runner's Complete Guide to Race-Day Fueling
The Runner's Complete Guide to Race-Day Fueling

You've logged the miles, conquered the long runs, and fine-tuned your pacing strategy. But here's the hard truth: all that training means nothing if you bonk at mile 20 because you didn't fuel…

Training Load vs. Training Stress for Runners
Training Load vs. Training Stress for Runners

Your watch says you're recovered. Your legs say otherwise. This disconnect happens because modern running analytics track two fundamentally different metrics that runners often confuse: training load…

A Runner's Holiday Survival Guide: Stay Training Ready
A Runner's Holiday Survival Guide: Stay Training Ready

The alarm goes off at 5:30 AM on December 27th. You're sleeping in your childhood bedroom, three time zones away from home, and your training plan says you need to knock out 18 miles today. Your…

Indoor Track Running: Your Weather-Proof Training Alternative
Indoor Track Running: Your Weather-Proof Training Alternative

The forecast shows freezing rain. Your treadmill sits in the basement, its belt squeaking ominously. You've got a tempo run scheduled, and neither option sounds appealing. But there's a third choice…

Base Building for Spring Marathons: Your October-November Blueprint
Base Building for Spring Marathons: Your October-November Blueprint

October arrives with cooler air and shorter days. While some runners wind down their season, the smartest ones are lacing up for something different. They're building the foundation that will carry…

The Marathon Taper: Why Doing Less Makes You Faster
The Marathon Taper: Why Doing Less Makes You Faster

You've logged hundreds of kilometers over sixteen weeks. You've conquered interval sessions that left you breathless, survived long runs that tested your mental fortitude, and pushed through those…

Gear & Practical (10)

Watches, packing, race-week logistics, and everything around the running itself.

Are Carbon-Plated Running Shoes Legal in Marathons?
Are Carbon-Plated Running Shoes Legal in Marathons?

The Nike Alphafly 3 has a 38.1-millimeter heel and sits on World Athletics' approved list. The Asics Superblast has a 42.7-millimeter heel and does not. World Athletics, the sport's global governing…

Best Running Shoes of 2026 So Far: Who Each One Is For
Best Running Shoes of 2026 So Far: Who Each One Is For

Shopping for a running shoe in 2026 means wading through reviews full of marketing-speak such as featherweight foams and race-day carbon plates. The seven shoes you'll see in this article, each…

Post-Marathon Blues: The Emotional Comedown After 26.2
Post-Marathon Blues: The Emotional Comedown After 26.2

You crossed the finish line. You got the medal. You posted the photos. Now you're standing in your kitchen three days later, staring at your running shoes, and feeling... empty. This wasn't supposed…

Race Week Logistics: Hotels, Packet Pickup, Peace of Mind
Race Week Logistics: Hotels, Packet Pickup, Peace of Mind

You've logged the miles. You've dialed in your nutrition. You've visualized crossing that finish line a hundred times. Then race week arrives, and suddenly you're scrambling to figure out where your…

Garmin vs. Polar vs. COROS: Which Running Watch?
Garmin vs. Polar vs. COROS: Which Running Watch?

Standing in a running specialty store, staring at three nearly identical GPS watches with wildly different price tags, you might wonder which brand deserves your training budget. Garmin, Polar, and…

The Marathon Gear Audit: What Actually Matters After 26.2
The Marathon Gear Audit: What Actually Matters After 26.2

I've crossed 14 marathon finish lines, and each time I conduct the same ritual. Before I collect my medal, before I grab that foil blanket, I perform a mental inventory. What gear actually helped?…

Marathon Spectator Guide: Supporting Your Runner on Race Day
Marathon Spectator Guide: Supporting Your Runner on Race Day

You've watched your runner disappear into the bathroom for the third time before breakfast, listened to endless discussions about gel flavors, and surrendered your weekends to training runs that…

The Marathon Packing & Travel Checklist
The Marathon Packing & Travel Checklist

Nailing Race-Day Logistics Before You Even Leave Home Nothing derails 4 months of training like a forgotten pair of shoes or gear lost in translation. Join me as I break down the travel tested…

42Cal Pro vs. Strava: Why Runners Still Need a Dedicated "Race OS"
42Cal Pro vs. Strava: Why Runners Still Need a Dedicated "Race OS"

TL;DR Strava is still the go-to app for tracking and sharing every run, but a marathon is more than a string of GPS files; it's a months-long project with travel plans, gear choices, race-week tasks…

Welcome to 42Cal
Welcome to 42Cal

We built 42Cal with the goal of inspiring more people to run long distance. Running is an art and we want to foster this art. The races we share on our site are curated and the list will be ever…