The Celerix Journal

Training guides, no fluff

Evidence-based advice on endurance training, written for runners and cyclists who want to train smarter.

All Training Science AI Coaching Marathon Training Cycling Triathlon Training Guides
Triathlon

How to build a triathlon training plan: Sprint to Ironman

Swim, bike, and run don't train the same way in combination as they do apart. Here's how to balance all three, from a 6-week Sprint build to a 6-month Ironman campaign.

6 Jul 2026 · 9 min read
Cycling

Cycling training zones explained

Pace is useless on a bike. FTP-based zones give you a terrain-independent measure of effort — and a smarter way to structure every ride.

22 Jun 2026 · 8 min read
Training Science

How to prevent running injuries

Most running injuries are predictable. Read your Form score and training load before a nagging ache becomes weeks on the sideline.

8 Jun 2026 · 8 min read
Recovery

How to structure a recovery week

Recovery weeks aren't rest weeks — they're when your fitness gains take hold. When to take one, and what to actually do.

5 Jun 2026 · 7 min read
Training Science

Using Strava data to improve training

Your Strava feed is more than a log. Read pace trends, training load, and segment data to train smarter.

6 Mar 2026 · 8 min read
Training Science

Running pace zones explained

What pace zones are, why most runners train in the wrong ones, and the simple fix that unlocks progress.

6 Mar 2026 · 7 min read
Training Guides

From 5K to marathon: choosing a plan

Each race distance demands a different approach. Here's what your plan should actually look like, 5K to marathon.

6 Mar 2026 · 9 min read
Marathon Training

How to build a marathon training plan

Base, build, peak, taper — a practical framework for structuring the weeks around your goal race.

18 Feb 2026 · 8 min read
AI Coaching

AI running coach: does it actually work?

An honest look at what AI coaching can and can't do — and how to get the most out of it.

18 Feb 2026 · 7 min read
Training Science

Heart Rate Training for Runners: How to Use HR Zones

Learn how to train in the right zone every day, find your lactate threshold heart rate, and apply the 80/20 rule to build a bigger aerobic base.

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