What Is the 80% Rule in Running? (80/20 Running for Garmin Users)
The 80% rule (or 80/20 running) means 80% of your runs should be easy and 20% hard. A practical guide for Garmin users.
Read morePersonalised plans
Run smarter, not harder
Adaptive training that fits your week.
Stop failing your training plan because life got in the way.
Sync your Garmin and get a professional training plan. Sync an on-demand workout based on your actual training history when you can run or get to the gym.Built for runners chasing 5K to marathon goals - without spreadsheets or guesswork.
Your plan adapts automatically
Missed a run or improved faster than expected? The coach works off your data, not your plan.
Fits your real schedule
Workouts are ready in your Garmin Connect ready for you to execute.
Built by AI, guided by your data
Your training evolves based on your performance, not static formulas.
You're Not Doing It Wrong
Running shouldn't feel this hard
You've probably experienced at least one of these:
- •You're told to "slow down", but still end up injured
- •You miss a run and suddenly don't know how to adjust your plan
- •Advice about zones, mileage, shoes, and strength work feels overwhelming
- •You're putting in the effort, but not seeing the progress you expected
Most plans assume perfect consistency and unlimited time.
Real life doesn't work that way.
The problem isn't your motivation — it's rigid plans
Runners don't fail because they lack discipline.
They struggle because most plans don't adapt when:
- •Life gets busy
- •Runs get missed
- •Fatigue or soreness builds up
- •Progress stalls or feels unclear
When that happens, runners are left guessing:
Do I repeat the week? Skip ahead? Push through?
How runthetic helps
runthetic is designed to guide runners through real-world training by:
Adapting your training when runs are missed
Keeping guidance simple instead of overwhelming
Helping you build consistency without burnout
Focusing on what to do next - not just what you already did
You still do the running. runthetic helps with the decisions.
Where Garmin Coach stops
Garmin Coach is a great starting point, especially if you want a structured plan that lives entirely on your watch.
runthetic is built for runners whose training doesn't always go to plan. Instead of locking you into a fixed schedule, it adapts your training based on what you actually run. It's suggested running and strength workouts that evolves with you and can be steered by you.
With runthetic, you can:
- Automatically adjust training after missed or extra runs
- Generate workouts for today or the coming days, on demand
- Keep progressing without restarting a plan
- Use your existing Garmin data, with workouts synced back to your watch - no new devices required
- Get supplemental strength workouts synced directly to your Garmin watch, without manually searching for or building sessions
- Have workouts adapt to conditions like heat and humidity (weather-aware training coming soon)
The result is training that feels flexible, realistic, and easier to stick with over time.
How it works
- 1. Connect
Link your Garmin Connect account and set your goal (e.g. 10K PB, base, marathon).
- 2. Plan
Your AI coach builds your next session with rationale.
- 3. Execute
Sync to your Garmin Connect calendar and go. Adjustments happen automatically.
Connect your ecosystem
Link your Garmin Connect account to sync your activities with runthetic - your activities feed into the generation of your next workout.
Your coach, your way
Guide the AI coach further with a run preference and by selecting a Coach who favours your training preference.
Seamless execution
runthetic will generate a Garmin Connect running workout for you which syncs to your Garmin device in 30 seconds - sync your watch and run.
Runner's Guide
Answers to common running questions
Practical advice on training, nutrition, and recovery. No fluff, just what works.
How Should I Breathe While Running?
Learn how to breathe efficiently while running, when to use nose vs mouth breathing, and how breathing affects performance and heart rate.
Read moreWhat Is Running Cadence and Why Does It Matter?
Running cadence is often misunderstood-learn what it is, how it affects efficiency and injury risk, and whether you should try to change yours.
Read moreBuilt by a runner who's been there
I built runthetic after running into the same problems many runners face — missed sessions, disrupted plans, and the frustration of not knowing how to adapt without starting over.
Today, runthetic uses your real runs to adjust training automatically, so plans stay realistic even when life gets in the way.
It's built with feedback from runners at all levels, with one goal: make training feel sustainable, flexible, and progress-driven — not overwhelming.