🏃 Welcome to Your Weekly Endurance Briefing

Welcome to your weekly endurance briefing, courtesy of Marathon Journal. Each Monday, we bring you the latest news, stories, race reviews, and gear insights from the world of running and endurance sports.

📰 NEWS

1. Chicago Marathon Pop-Up and Event Guide

Heading to Chicago or running the 26.2 next week? The Windy City isn't just hosting a race—it's throwing a full-scale running festival from Wednesday through Tuesday.

To help you navigate the chaos, we put together the ultimate day-by-day directory of shakeout runs, athlete panels with Des & Kara, gear pop-ups, cheer zones, and post-race medal celebrations.

Huge shoutout to our friends at Marathon-Weekend.com or compiling this insane master schedule! Check out our full guide to map out your week, or hit their interactive portal to get exact addresses, RSVP links, and live updates.

👉 [READ THE FULL CHICAGO MARATHON WEEK GUIDE]

2. Dates of Elite Races Confirmed for Historic 2027 Double TCS London Marathon via Rock-Paper-Scissors

When a record 1.33 million applicants entered the 2027 TCS London Marathon ballot, organizers responded with a historic, one-off expansion: "The Double," hosting 100,000 runners across two consecutive days. But with both elite fields needing designated race days, CEO Hugh Brasher settled the schedule in the most unexpected way possible.

World record holder Sabastian Sawe faced off against nine-time world record holder Catherine Debrunner in an official game of rock-paper-scissors. Find out who won, which elite race lands on Saturday versus Sunday, and how this once-in-a-generation double weekend will work for field splits, charity targets, and course staging.

👉 [Read the full article on MarathonJournal.com]

3. Why the Marathon Has Two Women’s World Records

When Ruth Chepngetich ran 2:09:56 in Chicago and Tigst Assefa ran 2:15:41 in London, both set official world records. How can two vastly different times hold the exact same title? It comes down to race field mechanics, drafting physics, and staggered start lines. In our latest feature on MarathonJournal.com, we break down the science, history, and staging logistics behind the dual-record framework—and why both marks deserve their place in distance running history.

👉 [Read the Full Article on MarathonJournal.com]

4. The 2027 Boston Cut-Off Is Here!

The numbers are in for the 131st Boston Marathon! The B.A.A. announced a 5:17 cut-off time, meaning runners needed to beat their age-group standard by 5 minutes and 17 seconds or faster to punch their ticket to Hopkinton.

A record 25,630 qualified athletes have been accepted, including 1,000 runners selected through the new Boston Qualifier Selection lottery. Check out our full breakdown of the acceptance stats, global demographics, and what's next for those eyeing April 19, 2027.

👉 [Read the Full Story on Marathon Journal]

THIS WEEK ON THE POD

5. The Danger of Underfueling: Why Endurance Athletes Are Running on Empty

The core of performance nutrition revolves around one of the most pervasive yet misunderstood challenges in distance running today: underfueling, Low Energy Availability (LEA), and Relative Energy Deficiency in Sport (REDs). In this episode, sports nutritionist Erin Sparrold breaks down how ignoring the body's metabolic baseline can derail athletic performance, compromise bone density, and impact long-term health.

👉 [Listen to the Full Episode on Marathon Journal OR read the article]

REVIEWS

6. Mizuno Neo Zen 2: The High Stack Mileage Eater

When a daily trainer undergoes a massive personality shift, it takes a few miles to figure out its true calling. The new Mizuno Neo Zen 2 swaps out its predecessor's overly squishy feel for a controlled, nitrogen-infused Enerzy NXT foam setup. Weighing in at 8.5 oz with a 6mm drop and a towering 40mm heel stack, this $160 plate-less workhorse pairs Smooth Speed Assist rocker geometry with a secure hybrid knit upper. We put it through months of testing to see why it makes a brilliant, shock-absorbing long run companion as long as you keep it strictly off your casual walking rotation.

👉 [Read our full, unfiltered breakdown at MarathonJournal.com]

7. Puma Deviate Nitro Elite 4: Featherweight Speed Meets Elite Nitrogen Power

When a racing shoe looks this stunning and performs even better, it deserves a spot at the front of your rotation. The new Puma Deviate Nitro Elite 4 combines a max-cushion 40mm heel stack with an upgraded nitrogen-infused NITROFOAM Elite midsole and a reengineered carbon fiber PWRPLATE. Weighing in at an astonishing 5.6 oz with an 8mm drop, this $250 race-day weapon delivers explosive energy return, an ULTRAWEAVE lockdown upper, and legendary PUMAGRIP traction. We put it through top-tier speed testing to see how its featherweight agility handles the ultimate test of race-day pacing.

👉 [Read our full, unfiltered breakdown at MarathonJournal.com]

8. Therabody JetBoots Review: A Full Year Testing Cordless Compression on the Run

Traditional pneumatic compression boots usually mean tethering yourself to an outlet with a maze of air hoses and a bulky control box. We spent a full twelve months testing the Therabody JetBoots through peak marathon training cycles and race travel to see if fully integrated, untethered leg compression is worth the investment.

Featuring fully wireless TruGrade sequential compression, a hygienic non-porous interior lining, and 3 hours of battery life per charge, these boots eliminate setup friction entirely. Read our full breakdown on how they perform for post-long-run flushing, travel packability, and lower-leg fatigue recovery.

👉 [Read our full, one-year long-term review of the Therabody JetBoots on MarathonJournal.com]

Keep running. Keep exploring. Keep reading Marathon Journal.