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.

38 articles · updated August 3, 2026

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Data Studies (10)

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

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 deg

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 o

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 stayi

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 2

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 tha

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

The First-Timer's Marathon Mistake Catalog: Learning from 50,000 Race Reports Every marathon finish line tells two stories. The first is the official race report, posted with pride in running forum

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

Running Tourism Economics: How Marathons Transform Small Cities The economics of running tourism tell a story that municipal planners and race directors have learned to read with increasing precisi

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

Decoding Marathon Elevation Profiles 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

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

Introduction and Summary 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.

Race Guides (12)

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

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

No course in modern marathon history has produced than Berlin's. Between 1998 and 2022, men racing the BMW Berlin Marathon, one of t

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 26

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

Cape Town Marathon: Running Between Two Oceans at Africa's Southern Tip The morning air carries salt from two different oceans. Table Mountain looms above, its flat summit catching the first light.

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

The Best Races in Mexico 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 c

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

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

Dubai Marathon: Chasing Fast Times Under Desert Stars
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

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

Valencia Marathon: Chasing Personal Bests on Spain's Fastest Course It's 8 AM on a December morning in Valencia, and the air hums with a particular energy. Runners from 80 countries stretch along w

Ljubljana Marathon: Slovenia's Charming Autumn Classic
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

Athens Marathon: Running Where It All Began
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 P

Running Japan: Tokyo Marathon & Beyond
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. I

Discovering the Maratona di Ravenna
Discovering the Maratona di Ravenna

Running Through Mosaics: Discovering the Maratona di Ravenna, Italy's Hidden Gem Marathon A Mosaic of Memories at the Starting Line It's 6 AM in Ravenna, and the air is thick with anticipation

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, th

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 wo

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

The Runner's Complete Guide to Race-Day Fueling: From Training to Finish Line You've logged the miles, conquered the long runs, and fine-tuned your pacing strategy. But here's the hard truth: all t

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

Training Load vs. Training Stress: What Runners Need to Know Your watch says you're recovered. Your legs say otherwise. This disconnect happens because modern running analytics track two fundament

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

The 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 trainin

Indoor Track Running: Your Weather-Proof Training Alternative
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,

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

Base Building for Spring Marathons: Your October-November Training Blueprint October arrives with cooler air and shorter days. While some runners wind down their season, the smartest ones are lacin

The Marathon Taper: Why Doing Less Makes You Faster
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 tes

Gear & Practical (9)

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

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 focusi

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

Post-Marathon Blues: The Emotional Comedown Nobody Warns You About You crossed the finish line. You got the medal. You posted the photos. Now you're standing in your kitchen three days later, stari

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

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

Garmin vs. Polar vs. COROS: Which Running Watch for Marathon Training? Standing in a running specialty store, staring at three nearly identical GPS watches with wildly different price tags, you mig

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

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

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

The Complete Marathon Spectator Guide: Making Race Day Special for Your Runner You've watched your runner disappear into the bathroom for the third time before breakfast, listened to endless discus

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 esse

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 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 trave

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 expan