Your Pacer — Polarized aerobic-base coaching, by email

01 — How it works

Three steps.
No app to install.

STEP 01

Connect your watch

COROS, Garmin, Polar, Suunto, WHOOP, Oura — the device you already use, linked in a single click.

STEP 02

Receive your analysis

Within minutes, one email arrives. Your aerobic threshold. Its ratio to anaerobic threshold. What to work on first.

STEP 03

A coach that remembers you

A plan for your goal race — or for weight, or staying fit. A brief before each session, analysis after you finish, a weekly review and the next week's plan every Sunday evening.

02 — No dashboard needed, email is everything

It arrives in your inbox.

Your watch already has a good dashboard. What it lacks is a coach who reads it for you. Every brief we send is the product — and the longer we write to you, the more of you we remember.

Your Pacer MON · 20 APR 2026 · 20:00

Pre workout

Good evening.

You noted after Sunday's long run that the legs felt light — "last km could have been faster." Tomorrow's threshold stays on schedule and lands 2 s/km quicker than last week.

INTENT ·A short threshold session. Returning to quality, not chasing a record.

Three steady Z2 weeks have done their work. Aerobic HR has dropped 4 bpm at the same pace.

Eight minutes is long enough to ask something of you, short enough to keep you out of trouble.

Prescription · tomorrow 06:00

WARM-UP
20 min · Z1 · HR 120–135

MAIN
3×8 min · Z3 · HR 168–172
(2 min jog between reps)

COOL
10 min · Z1 · HR 120–130

If the warm-up says no, stop after the first rep and reply. Nothing to make up.

Aim for seven hours of sleep tonight. Caffeine before is fine.

One question — any asymmetry in the knees this week?

Your Pacer SAT · 18 APR 2026 · 17:43

Post workout

Good evening.

You wrote yesterday that the knees felt even. Today's drift came back flat, which reads well against that.

INTENT ·The base is building, steadily.

18.2 km · avg HR 146 · drift 2.1% · 5:48/km. You held below AeT through the full distance.

A month ago the same pace sat at 152 bpm. Seventeen seconds per kilometer, same heart, same shoes.

DISTANCE
18.20 km (+0 km vs prescribed)

AVG PACE
5:48 /km

AVG HR
146 bpm (AeT − 2)

HR DRIFT
2.1% (below AeT ✓)

Tomorrow is easy. Not moderate.

If the legs feel light, let them. Run by heart rate — don't let the feel push the pace.

One question — what did the legs say in the final 3 km?

Your Pacer SUN · 19 APR 2026 · 20:00

Weekly review

Good evening. Seven days done.

Your note last week — "the final 3 km was not heavy, just slower" — reads as aerobic cost, not muscular fatigue. AeT stays where it is; next week's long run holds the same distance.

INTENT ·The base is steady. Quality comes back next week, carefully.

Week 17 · summary

DISTANCE
44 km (target 42, +4.8%)

QUALITY
1 session · 3×8 min at T-pace

LONG RUN
18 km · drift 2.1% · below AeT ✓

EASY RATIO
82% (target ≥ 80%)

HRV TREND
stable · −1%

— On Wednesday's T-pace, clearance after rep three came back faster than after rep one. Likely AnT is rising.

— Long run, final 3 km — the rhythm dropped. Not heaviness; the pace just eased off.

Next week · plan

MON
Rest — full day off

TUE
Easy 10 km · Z1 · HR <140

WED
Quality 4×8 min T-pace
(−2 s/km from last)

THU
Easy 8 km · Z1 · HR <140

FRI
Rest / optional 40 min Z1

SAT
Easy 12 km · hilly · Z1

SUN
Long 20 km
last 3 km observation

— Same quality structure, T-pace pulled 2 s/km faster.

— Long run extends to 20 km. Last 3 km becomes an observation segment.

— Aim for 8 hours of sleep over the weekend mornings.

One question — the first 3 minutes of Wednesday's last interval: what did that feel like?

03 — The method

Polarized aerobic-base training.
Three lineages, one coach.

Your Pacer is built out of three endurance traditions that, together, form a coherent training philosophy. We read Daniels' Running Formula, Advanced Marathoning, and Training for the Uphill Athlete as complementary texts, not competing ones, and distilled their common ground into the decisions behind each email you will receive.

Aerobic base comes first

80–90% of your volume sits at or below aerobic threshold. Intensity only enters once the base is deep enough to hold it — and only in doses your recovery can absorb.

Aerobic Deficiency Syndrome is treated seriously

If your aerobic threshold sits too far below your anaerobic threshold, Your Pacer will not prescribe intensity — however much you want it. This is where most athletes break themselves.

Periodization is explicit

Transition. Base. Bridge. Specific. Taper. You always know which phase you are in and why this week looks the way it does.

No manufactured praise

If you skipped, we say so. If you pushed through something that needed rest, we say that too. The coaching is only useful if it is honest.

Life is a training variable

Sleep, travel, a sick parent, a heavy week at work. These go into the plan, not around it.

For trail and ultra athletes

Vertical capacity and muscular-endurance work are woven into the weekly plan — climbing base built long before race week. Per-workout cumulative-elevation context is part of every analysis.

Z1 · recovery < 60% of max HR

Z2 · aerobic base 60–78%

Z3 · threshold 78–88%

Z4 · VO2 88–95%

Z5 · neuro 95%+

base volume

threshold

vo2 / neuro

Two decades of published endurance research, synthesised from three lineages — Daniels (VDOT, pace precision), Pfitzinger (marathon-specific MLR), Johnston (mountain athletes, ADS, mountain patience). Methodology, not proprietary IP.

04 — Pricing

Analysis is free. Monthly subscription.
Cancel with one reply.

Free

One free analysis to meet your coach

¥0

No card required

90-day analysis from your watch
Aerobic / anaerobic threshold estimate
AeT / AnT ratio and interpretation
Current limiters identified
Race-time prediction for your A-race
Recurring coaching starts with Standard

Start free

Standard

Sunday plan, every week

¥1,500 / month

tax incl · cancel anytime

Weekly plan every Sunday evening
Weekly review with threshold updates
Reply anytime — the plan adapts each week
A coach that remembers, the longer you stay
Pre / post-workout briefs are Advanced

Start with Standard

Advanced

Full daily coaching, by email

¥2,980 / month

tax incl · cancel anytime

Everything in Standard
A brief the night before each session
Analysis within an hour of finishing
Day-by-day protocol through race week
Weekly threshold + form trend visuals

Start with Advanced

A future Max tier (≈ ¥7,480/month, including real-time chat) is in the queue. Standard / Advanced subscribers will be notified first.

05 — Common questions

FAQ

What is "polarized aerobic-base" training?

A way of skewing training to roughly 80% easy + 20% hard, deliberately avoiding the middle "grey zone" where adaptation stalls. Two decades of endurance science converge on it. Read more →

Is Your Pacer safe to follow without a human coach?

For general training, yes — in the same sense that reading a training book is safe. For diagnosed medical conditions, recent surgery, or acute injury, Your Pacer will point you to a clinician. Medical red-flag detection is built into every reply we process.

What if I get injured mid-plan?

Reply to any email with what's happening. Next week's plan gets rewritten. If we detect certain patterns — sudden severe pain, neurological symptoms, chest or cardiovascular issues — we pause the plan and recommend seeing a professional.

Which watches are supported?

COROS, Garmin, Polar, Suunto, WHOOP, Oura — through your existing account. We read activity, heart rate, sleep, and HRV; nothing else.

When do the emails arrive?

Post-workout analysis within an hour of finishing. A pre-workout brief the evening before a training day, at 20:00. Weekly review Sunday at 20:00 — all on your local time.

What if I miss a week?

Nothing happens. No guilt email, no "streak lost" notification, no algorithmic judgment. You pick up with the next Sunday's plan. Your Pacer notes the missed week and adjusts volume accordingly.

Are my replies actually read?

Yes. Every reply goes into your memory and shapes next week's plan. If something needs human attention, we route it for review. You never reply into a void.

Why no dashboard?

Your watch already has a thorough dashboard. Another one would only fragment your attention. What you actually need is an objective reading of that data and a plan tailored to you — and it arrives in the inbox you already open every day.

What is "anti-sycophancy" and why does it matter?

Most AI coaches default to flattery. Skipped the long run? "Nice recovery!" Your Pacer doesn't do that. If you skipped, we name it and rewrite the plan. If you pushed on a rest day, we say so. Coaching is only useful when it is honest — and honesty is harder to fake than praise.

How is this different from ChatGPT with a training prompt?

ChatGPT forgets everything the moment you close the chat. Your Pacer remembers six months of your training, your preferences, your races, the week you had a cold. That memory — not the model — is the product.

Your Pacer v1.0

Three steps.
No app to install.

Connect your watch

Receive your analysis

A coach that remembers you

It arrives in your inbox.

Polarized aerobic-base training.
Three lineages, one coach.

Aerobic base comes first

Aerobic Deficiency Syndrome is treated seriously

Periodization is explicit

No manufactured praise

Life is a training variable

For trail and ultra athletes

Analysis is free. Monthly subscription.
Cancel with one reply.

FAQ

Start with the free first read.

Three steps.No app to install.

Connect your watch

Receive your analysis

A coach that remembers you

It arrives in your inbox.

Polarized aerobic-base training.Three lineages, one coach.

Aerobic base comes first

Aerobic Deficiency Syndrome is treated seriously

Periodization is explicit

No manufactured praise

Life is a training variable

For trail and ultra athletes

Analysis is free. Monthly subscription.Cancel with one reply.

FAQ

Start with the free first read.

Three steps.
No app to install.

Polarized aerobic-base training.
Three lineages, one coach.

Analysis is free. Monthly subscription.
Cancel with one reply.