June 17, 2026·5 min read
You're a Runner Now. You Can Eat Whatever You Want, Right?
Running burns calories, but it does not erase them. Here is the real math behind why so many runners do not lose weight despite all those miles.
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For serious runners
Get nerdy about your next PR
Training plans for experienced runners. Running advice for everyone. Built on real exercise physiology, not generic templates or AI slop. Free forever.
What we offer
Everything a serious runner needs. Free.
Training Plan Generator
Personalized half marathon and marathon plans built from your actual fitness. Base, build, peak, and taper phases. Cutback weeks built in. Download as PDF, Excel, or Garmin FIT files.
Build my plan →Running Pace Calculator
Enter a recent race time and get your fitness score, equivalent race predictions, and all your training paces — easy, tempo, intervals, marathon pace, and more. Instant results.
Calculate my paces →Training Advice
No corporate sponsorships. No paid product placements. Just honest training content backed by real exercise physiology. Paces, periodization, fueling, gear, and everything in between.
Read the articles →Race Finder
Find upcoming marathons, half marathons, 10Ks, and 5Ks near you or browse races in major US running cities. Powered by RunSignup.
View Races →Latest
From the articles
June 15, 2026·5 min read
How Often Should You Race? The Tune-Up Race vs The Endless Race Calendar
A 5K here and there can sharpen your training. A half marathon every few weeks can quietly wreck it. Here is how to tell the difference.
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June 10, 2026·7 min read
What Running a Marathon Actually Costs You
The entry fee is the cheap part. Here is what a marathon actually demands from your time, your body, your nutrition, and your family before you ever reach the start line.
Read more →
Who the training plans are for
Built for runners who want to get faster.
This is for you if...
- ✓You know what a tempo run is
- ✓You track your weekly mileage or distance
- ✓You have a specific goal time in mind
- ✓You have run a half or full before
- ✓You are chasing a PR, not just a finish line
- ✓You have a fitness watch to monitor your paces
New to running?
Our training plans assume you already have a running base and some race experience. If you are just getting started, our articles are a great place to begin. We cover pacing, training zones, fueling, and gear without assuming any prior knowledge.
Start with the articles →Sample output
This is what your plan looks like
Week 8 of an 18-week marathon plan, Fitness Score 47, targeting 3:30.
Week 8Build
Build phase — intervals and marathon pace long run
44 mi
Mon
Aug 4
Easy7 miles @ 8:39–9:15/mi — aerobic base, settle in
Tue
Aug 5
Intervals8 miles w/ 7x800m @ 3:16 per 800m, 90-sec jog recovery
Wed
Aug 6
Recovery5 miles @ 10:00/mi — truly easy after hard intervals
Thu
Aug 7
RestRest day — full recovery
Fri
Aug 8
Easy7 miles @ 8:39–9:15/mi + 4x20-sec strides
Sat
Aug 9
Long17 miles: first 13 @ 9:15/mi, miles 14-17 @ 7:52/mi marathon pace
Sun
Aug 10
RestRest day — full recovery after long run
FAQ
Questions
What is a Fitness Score?
Your Fitness Score is calculated from your recent race time and represents your current aerobic fitness level. It sets your training paces for easy runs, tempo runs, intervals, and long runs. The higher the score, the faster the paces.
What recent race time should I use?
Use your most recent all-out race effort from the last 6 months. A 5K, 10K, half, or full marathon all work. The more recent and honest the effort, the more accurate your paces will be.
Do I need a Garmin to use this?
No. The PDF and Excel downloads work for anyone. If you have a Garmin or Coros watch, you can also export your plan as FIT files and load them directly to your watch via USB.
How is this different from other plan generators?
Most plan generators are built for beginners or use generic templates. PR Nerd calculates your paces from your actual current fitness, not your goal time. You get structured periodization, cutback weeks, and race-specific workouts. And it is completely free.
What if my race is only 6 weeks away?
We support half marathon plans as short as 6 weeks and marathon plans as short as 10 weeks. Shorter blocks focus on race-specific sharpening rather than base building.
Can I redo my plan?
Yes — just go back to the plan generator and enter updated information. Each plan generates fresh from your current inputs.
I use KM instead of miles, do you support this?
Yes — PR Nerd training plans are now kilometers or miles, you choose.
Ready to get serious?
Free training plans, pace calculators, and advice built for runners who actually care about getting faster.