Currently in development — Join the waitlist for early access
Runner on trail

The
forge
runs
on
science.

Tanren (鍛錬) — the Japanese concept of forging through disciplined repetition. Like a blade shaped by countless strikes, you are refined through consistent training. No shortcuts. No hacks. Just the quiet accumulation of kilometres that transforms you into a stronger runner.

Evidence-based running plans. Structured training built from peer-reviewed sports science — zone 2 development, polarised intensity distribution, periodised progression. From 5K to full marathon.

You're on the list! We'll notify you at launch.
Currently in development. No spam. We'll notify you at launch.
New to Running?

Start where
you are.

Tanren isn't just for experienced runners chasing PRs. Our plans adapt to your current fitness level — whether you're running your first 5K or returning after time off.

Walk-Run Progressions

Couch to 5K style intervals that gradually build your running fitness. No pressure, no judgment — just consistent forward progress.

Sustainable Volume

Plans that respect where you're starting from. Gradual mileage increases that build the aerobic base without burning you out.

Recovery Built In

Rest days aren't optional — they're where adaptation happens. Every plan includes proper recovery to keep you healthy and progressing.

Every kilometre has a

STRUCTURED · PERIODISED · EVIDENCE-BASED

Method

Four phases.
One process.

Every training block follows a disciplined arc from aerobic base through race-day peak. The periodisation model used by elite coaches worldwide.

1

Base Building

Aerobic foundation. Zone 2 volume. 8-12 weeks of steady mileage building the cardiovascular engine that everything else depends on.

2

Build Phase

Progressive overload. Tempo and interval work layered onto the aerobic base. Weekly volume peaks. Structured recovery between hard sessions.

3

Peak & Sharpen

Race-specific intensity. VO2max intervals, goal-pace tempo, dress rehearsal long runs. Sharpening the blade the base phase forged.

4

Taper & Race

Strategic 2-3 week volume reduction while maintaining intensity. Supercompensation. You arrive at the start line forged and fresh.

WEEKS 1-8
Base
Zone 2 volume, aerobic foundation
70-80% Z1-Z2
WEEKS 9-14
Build
Tempo, intervals, peak volume
75% Z2 + 15% Z3-Z4
WEEKS 15-17
Peak
Race-pace, VO2max, specificity
80/20 POLARISED
WEEKS 18-20
Taper
Volume ↓40%, intensity maintained
SUPERCOMPENSATION
80%
Easy / Zone 2
20%
Hard / Zone 4-5
5
Heart Rate Zones
5
Race Distances
Research

Built on
peer-reviewed
evidence.

Every protocol in Tanren is grounded in published sports science. These are some of the key findings that shaped our training model.

Zone Distribution
80 /20
15% Z1 Recovery
55% Z2 Aerobic
15% Z3 Tempo
15% Z4-5 VO2max
Seiler's polarised model: ~80% below VT1, ~20% above VT2. The "threshold zone" (Z3) is minimised.
Weekly Volume · 20-Week Marathon Build
Base Build Peak Recovery
Progressive overload with recovery weeks (4, 8, 12). Peak volume at week 16, followed by 3-week taper. Colour indicates training phase.
2010
Polarised training intensity distribution in elite endurance athletes
Seiler, S.
Elite endurance athletes consistently organise ~75-80% of training at low intensity, with limited time in the moderate "threshold" zone. This polarised pattern outperforms threshold-focused approaches.
Int. J. Sports Physiology & Performance
2007
Training intensity distribution and marathon performance
Esteve-Lanao, J., et al.
Runners who devoted more training time to Z1 (below VT1) and less to Z2 (between thresholds) produced significantly better 10K race performances over a 5-month period.
J. Strength & Conditioning Research
2014
Polarised vs. threshold training intensity distribution on endurance performance
Stöggl, T. & Sperlich, B.
Polarised training improved VO2max (+11.7%), time to exhaustion, and peak speed more than threshold, high-volume, or high-intensity training alone over a 9-week period.
J. Strength & Conditioning Research
VO2max Improvement · Polarised vs Threshold
0% +6% +12% +11.7% Polarised +5.1% Threshold +6.2% High-Volume
Stöggl & Sperlich (2014): 9-week intervention in trained athletes. Polarised training produced the largest VO2max gains.
Training Distribution · What Elites Actually Do
Kenyan elite 78% 12% Norwegian XC 83% 10% Polarized 80/20 80% 10% Z1-Z2 Easy Z3 Moderate Z4-Z5 Hard
The polarized model aligns with observed training intensity distribution of elite endurance athletes across disciplines.
2019
How do world-class endurance athletes train?
Haugen, T., et al.
World-class endurance athletes typically train 10-13 sessions per week with a pyramidal or polarised intensity distribution. High training volumes at low intensity are the common denominator.
Sports Medicine
2022
The science and practice of middle- and long-distance running training
Casado, A., et al.
Systematic review confirmed that successful distance runners dedicate ~80% of training volume to low-intensity running, with progressive volume increases of 5-10% per week during build phases.
Sports Medicine — Open
2015
Training characteristics of marathon runners
Billat, V., et al.
Analysis of Kenyan and European elite marathoners showed the top performers maintained a higher proportion of training below the ventilatory threshold, with sharply targeted high-intensity sessions.
Int. J. Sports Medicine
Plan Preview

See your
training week.

Configure your race distance, experience, and preferred training week. The plan adjusts intensity distribution, volume, and session types in real time.

118
Strava Sync

Your runs,
automatically.

Connect your Strava account and Tanren imports your activities automatically. Pace, heart rate, elevation, cadence — everything synced to track your progress against the plan.

One-click OAuth connection. Only reads activity data. Disconnect anytime from your Strava settings.

Features

What the
plan includes.

Training tools built for runners who care about the science behind every session.

Week 14 · Build Phase

Adapting
MonRecovery runZ18km
Tue6×1000m intervalsZ412km
WedEasy + drillsZ210km
ThuTempo runZ314km
FriRest——
SatLong runZ230km
SunCross-trainingZ1—
Z1 15%Z2 55%Z3 15%Z4-5 15%

Structured Plans

5K, 10K, 15K, half marathon, and full marathon. Phase periodisation with daily workout guidance and automatic progression.

Zone Training

HR zones for every session. Polarised 80/20 model based on Seiler's research. VDOT-based pace zones.

Strava Sync

Automatic activity import. Pace, heart rate, elevation, cadence — synced directly from your Strava account.

Privacy First

7-day data cache with auto-expiry. Optional privacy masking for route start/end points. GDPR compliant.

Cross-Training

Strength, mobility, drills, and recovery protocols integrated into every training week.

Science-Led

Peer-reviewed protocols from Seiler, Esteve-Lanao, Billat, and decades of endurance research.

From 5K to 42.2K.

5K · 10K · 15K · HALF MARATHON · MARATHON

EVIDENCE-BASED TRAINING

The Science of Marathon Training

Understand the peer-reviewed research behind your training plan. From polarised intensity distribution to lactate threshold development — every workout is backed by science.

Explore Training Science
PEER-REVIEWED RESEARCH

The Science of Mind

Running isn't just cardiovascular training — it's a powerful intervention for mental health. Explore the research on depression, anxiety, sleep, cognition, and the runner's high.

Explore Mental Health Science

Start forging.

Join the waitlist for early access. Be the first to train with structured, evidence-based plans.

You're on the list! We'll notify you at launch.