Lake Sonoma 50
training plan
An adaptive 50 mile plan for a hilly course on trail, run in temperate April conditions, built around the three things Lake Sonoma 50 actually asks of you: relentless vertical, technical descending and ground that never flattens. Eighteen weeks written two at a time, from what you actually did in the two weeks before, and rewritten the moment you travel, get ill or something starts hurting.
This page describes the race and what its course, climate and date ask of a build. On Pro, the plan itself is written for you, from your experience, your weekly hours and your date, so two athletes entered in this race get different plans.
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Three demands, three answers
A generic 18-week 50 mile plan gets you to the start line. It has no idea about relentless vertical, technical descending or ground that never flattens.
On the ground, Lake Sonoma 50 is a hilly course on trail, with 3,000 m of climbing in it. It is usually held in April, when conditions are usually mild, which quietly removes the weather from your list of excuses. So over a 50 mile race, the cost is climbing strength you either built or did not, and the weather is unlikely to be the thing you end up blaming. There will be a few hundred to a thousand starters out there with you.
- Profile
- Hilly · trail
- Climbing
- 3,000 m · 60 m in every mile
- Usual conditions
- April · temperate
- Race season
- Spring, northern hemisphere
- Field
- Small · a few hundred to a thousand
The vertical is the event
Measured in miles this looks manageable. Measured in vertical gain it is a different sport. You get hours of climbing, hiking where running stops making sense, and a descent bill on the other side of every summit.
Training is built around vertical gain and time on feet instead of mileage, with hiking programmed as a real session. On Lake Sonoma 50 you will be hiking for a large part of the day.
Descending here is a skill you have to practice
Loose, steep or rocky descents ask for balance, braking control and nerve. Treated as recovery they cost you time and shred your legs for whatever comes after.
Repeated descent practice on terrain like the course, and eccentric strength so the legs holding you back at the end of Lake Sonoma 50 are still the ones you started with.
It never flattens out and it never really climbs
A course of constant small rises never lets you settle into one rhythm. Even pacing is impossible, effort drifts upward without you noticing, and the cost shows up as a split that falls apart late.
Sessions run on rolling terrain to fixed effort rather than fixed pace, so you learn what Lake Sonoma 50 costs at the top of each rise instead of chasing a number that the profile will not let you hold.
Getting in, and getting to the line
Adaptlete has no involvement in entry, allocation or ballots for any race. This is what the format asks of your planning.
First come, first served
Places usually go on general sale and disappear on a timetable rather than a draw, so the date you can control is the one you start on. Eighteen weeks back from April puts the first week in early December.
Small field
A small field means no pens and no queues, and nobody to tuck in behind when it gets hard, and on a hilly course the climbs are where the field concertinas. Over a 50 mile race, that is a long time to be running somebody else's race.
Trail
Trail, so the long sessions have to happen on ground like it. Footing, poles, descending and eating while you move are skills, and none of them are learnable on a treadmill in the last two weeks. The peak week puts hill repeats on it, months before April.
You will be training through the northern winter
Work backwards and a eighteen-week block for an April race opens around early December, running December through to April. That is the northern winter, and it is the half of the job most plans never mention. Most of your long sessions will start or finish in the dark, in weather that makes the warm-up longer than the session. Ice takes the pace out of your hands, a chest infection goes round in week six, and the treadmill stops being a punishment and starts being a tool. And the last block lands in April, with hilly ground, temperate conditions and a small field waiting at the end of it.
So the plan swaps outdoor quality for treadmill or turbo equivalents by effort rather than pace when the ground is unrunnable, and treats a week lost to illness as a rebuild rather than a hole to run through. Whatever the season takes out of two weeks, the work for relentless vertical, technical descending and ground that never flattens is what the rebuild puts back first.
- Weeks 1-7 December-January dark, cold and interrupted, so showing up matters more than intensity
- Weeks 8-11 January-February
- Weeks 12-18 · peak and taper February-April the weather turns mid-block; the ramp holds steady anyway
Months assume Lake Sonoma 50 keeps its usual April slot and that you take the full 18 weeks. Adaptlete builds from the date you enter.
A real week from a Lake Sonoma 50 build
This is the shape of the biggest week in 18: 5-6 sessions a week, 10H 45M of training, and one session that matters more than the rest. Two of them are here because of this course and not the distance: hill repeats for the hilly profile, and a race-hour rehearsal for conditions that are usually temperate. The key session itself is written for relentless vertical. For an April race, week 12 lands in March. Your version is written from your hours, your history and how far out you are.
- Every session says what it is for, in plain language
- Intensity you can scan down the week without reading
- Move any session to any day without breaking the block
| Day | Intensity | Session | Distance and duration |
|---|---|---|---|
| MON | Rest | Rest | |
| TUE | Zone 4, threshold | Hill repeats: 8 × 3 min climbing, easy back down | 8 mi1H10 |
| WED | Zone 2, easy | Race-hour rehearsal: moved to the hour the race starts | 7 mi1H05 |
| THU | Zone 3, steady | Strength: eccentrics & trunk | 45' |
| FRI | Rest | Rest | |
| SAT | Zone 3, steady | Long trail run: built around the vertical | 26 mi5H00 |
| SUN | Zone 2, easy | Back-to-back long day | 14 mi2H45 |
Something will go wrong.
That is the part we built for.
Nobody finishes an eighteen-week build without missing a week, and December through to April is a long time to stay lucky. The plans that fail are the ones that carry on as if nothing happened.
A work trip in week 10
Hotel treadmill, nothing else? Those days get rewritten around it.
Flu in January
The block rebuilds and ramps you back. Nothing is deleted.
A niggle at week 14
Loading comes off it, the rest of your week stays. And go see someone.
Questions people actually search
How many weeks do I need to train for Lake Sonoma 50?
Eighteen weeks is the usual build for a 50 mile race like Lake Sonoma 50, at 5-6 sessions a week. Counted back from an April race that opens the block around early December and runs it December through to April. Coming from a lower base, give yourself longer. With fewer weeks than that the plan compresses. It builds what it can from where you are, protects the work for relentless vertical, technical descending and ground that never flattens first, and tells you plainly what it had to leave out.
When should I start training for Lake Sonoma 50?
Lake Sonoma 50 is usually held in April, and the next edition an athlete could realistically build for is Spring 2027. Count back eighteen weeks from whatever date you enter and the block opens around early December, running December through to April. Adaptlete builds backwards from your date, so the whole 50 mile plan lines itself up the moment the date is confirmed. Entry runs on a separate clock (places here are first come, first served), and the training deadline is the one you control.
How much climbing is there at Lake Sonoma 50?
A hilly course on trail, with 3,000 m of climbing in it, and in April conditions are usually mild, which quietly removes the weather from your list of excuses. So the cost is climbing strength you either built or did not, and the weather is unlikely to be the thing you end up blaming. That combination is what the eighteen weeks are built around: relentless vertical, technical descending and ground that never flattens. The 50 mile race on its own would give you a completely different plan.
What kit do I need for Lake Sonoma 50?
Trail, so the long sessions have to happen on ground like it. Footing, poles, descending and eating while you move are skills, and none of them are learnable on a treadmill in the last two weeks. There is 3,000 m of climbing in it, about 60 m in every mile. Over eighteen weeks the plan puts the long sessions on ground like it and asks you to use the same pack, poles, shoes and food you intend to use in April. Check the organizers' own mandatory kit list. It is theirs, it changes, and we do not publish it.
How do I keep a Lake Sonoma 50 build going through the winter?
A eighteen-week block ending in April runs December through to April, which is the northern winter. Most of the long sessions start or finish in the dark, ice takes the pace out of your hands, and something goes around the office in the middle third. The plan swaps outdoor quality for treadmill or turbo work by effort rather than pace when the ground is unrunnable, and treats a week lost to illness as a rebuild instead of a hole to run through.
How long will I be out on the course at Lake Sonoma 50?
Long enough that the plan works in time on feet. There is 3,000 m of climbing in it, about 60 m in every mile. Over hilly trail in April that turns a 50 mile race into a day of moving, eating and problem-solving, so the eighteen-week block builds back-to-back long days and rehearses relentless vertical, technical descending and ground that never flattens at the effort you can hold for hours.
Is this an official Lake Sonoma 50 training plan?
No. Adaptlete is an independent training-plan service with no affiliation to the organizers of Lake Sonoma 50, and none is implied. We name the race because the plan is built around what its course, its format and its date ask of you.