Cold, Dark, and Long: 10 Training Tips for a January 50 or 100 Miler in the Woods

A winter ultra is a different animal. The distance alone would humble most runners, but stack a January start on top of it — short days, wet trails, temperatures that don’t cooperate, and hours of running into the dark — and you’ve got a race that rewards preparation and punishes the athlete who trained like it was a summer 10K. At Without Limits, we tell our endurance athletes the same thing whether they’re chasing a first finish or a course record: the woods in January don’t care how fit you are on paper. They care whether you did the specific work.

Here are the ten things that matter most when you’re building toward 50 or 100 miles of trail in the cold.

1. Build your base early — and make it boring

Time on feet is the currency of ultra running, and you can’t cram it. The single biggest predictor of a good day out there is a long, consistent base of easy aerobic mileage laid down over months, not weeks. If your race is in January, your base should be humming by late summer or early fall. Prioritize weekly volume you can actually recover from and repeat, and resist the urge to make every run “count.” Most of your training should be genuinely easy — conversational, unglamorous, and frequent. The magic isn’t in any one workout; it’s in the accumulation.

2. Live and die by the back-to-back long run

This is the workout that separates ultra training from marathon training. Running a long effort on tired legs — a long run Saturday followed by another substantial run Sunday — teaches your body to keep moving when it’s already fatigued, which is exactly what a 50 or 100 miler demands. Back-to-backs build durability, dial in fueling under stress, and give you a rehearsal for the second half of the race when everything hurts. Start conservative (say, a longer effort paired with a shorter one) and build the volume of both days over your key training block. You do not need to run the full race distance in training; you need to teach your legs to work tired.

3. Train the vert, then train it again

Trail ultras are won and lost on the climbs and descents, and most road runners drastically undertrain both. If your race has significant elevation, your training has to include significant elevation — there is no substitute. Just as important: practice power hiking. In a 100 miler, walking the ups efficiently is a skill, not a failure. A strong, purposeful hike often beats a labored jog uphill for both speed and energy conservation. And don’t neglect the downhills, which trash your quads harder than anything else. Descending under control and under fatigue is a trainable skill that saves your legs for the final miles.

4. Practice running in the dark — a lot

January days are short. A 50 miler likely starts or finishes in the dark, and a 100 miler means running through most or all of a night. Night running changes everything: your pace slows, your footing gets cautious, your brain gets sleepy, and low points hit harder at 3 a.m. than they ever do at noon. Do real training runs by headlamp so the dark feels normal instead of alarming. Learn your light’s battery life, carry a backup, and know how your depth perception and mood shift when the sun’s gone. The athletes who struggle most in the dark are almost always the ones who never trained in it.

5. Dial in your layering system before race week

Cold-weather gear is a system, and you rehearse it exactly the way you rehearse fueling. The goal is to stay warm without overheating and soaking your base layers in sweat, because wet plus cold plus wind is how hypothermia starts. Learn what combination of layers works for you at different temperatures and effort levels, and practice adding and removing layers on the move. Pay special attention to extremities — hands, ears, and feet lose heat fast — and to the sweat-then-stop problem at aid stations, where standing still in damp clothing chills you quickly. Nothing new on race day includes the jacket, the gloves, and the buff.

6. Respect cold-weather fueling and hydration

Cold weather quietly sabotages nutrition in two ways. First, it blunts your thirst, so you drink less even though you’re still losing fluid through sweat and respiration — dehydration is absolutely a winter problem. Second, cold slows your gut and makes gels stiff, bottles freeze, and appetite disappear. Practice eating and drinking on your cold long runs, not just your warm ones. Figure out which calories your stomach tolerates when it’s 30 degrees and you’re eight hours in, keep fluids from freezing (insulated flasks, bottles carried close to the body), and set time-based reminders to drink since you won’t feel like it.

7. Take foot care seriously — winter trails are brutal on feet

Wet, muddy, icy, snowy trails mean wet feet, and wet feet mean blisters, maceration, and misery over ultra distances. Foot management is a training topic, not just a race-day one. Test your sock system (many ultra runners swear by wool and by carrying a dry spare pair for a mid-race change), pre-treat hot spots with lube or tape, and practice a quick, efficient sock-and-shoe change so you can execute it cold-fingered at an aid station. Choose footwear with the traction your specific course demands, and if ice is a real possibility, know your options for added grip. Your feet are the one piece of equipment you can’t swap out mid-race.

8. Strength train for durability, not aesthetics

Two or three short strength sessions a week — think squats, lunges, step-ups, single-leg work, and core — build the resilience that keeps you healthy through a big training block and holds your form together in the final quarter of the race. The goal isn’t to get big or strong for its own sake; it’s to bulletproof the tissues that ultra volume tends to break down. Athletes who lift consistently tend to descend better, fatigue slower, and get injured less. A little goes a long way, and it’s one of the highest-return, lowest-time investments in your whole plan.

9. Train your mind like it’s a muscle

A 100 miler is an emotional roller coaster, and the low points are guaranteed — the only question is whether you’ve prepared for them. Learn to break the race into small, manageable pieces: the next aid station, the next climb, the next mile, rather than the terrifying whole. Rehearse your mantras and your “why” on hard training runs so you can reach for them at mile 78. Expect the dark patches, name them as temporary, and have a plan (eat something, fix a problem, change your self-talk) instead of panicking. Mental resilience is built the same way physical endurance is: by voluntarily spending time in discomfort and coming out the other side.

10. Rehearse everything — nothing new on race day

By the time you toe the line, your gear, your fueling, your pacing, your drop bags, and your layering should all be things you’ve already done, not experiments. Do a couple of key long runs in your full race-day setup: the exact pack, the poles if you use them, the shoes, the nutrition, the whole kit. Practice your drop-bag routine so aid-station stops are fast and deliberate. The winter woods will throw enough surprises at you without you adding self-inflicted ones. Confidence on race day comes from having already lived every piece of the plan.

None of this is complicated, but all of it is specific. Winter ultras reward the athlete who trained for this race — the cold, the dark, the terrain, the distance — rather than the athlete who was simply fit. Put in the base, do the back-to-backs, get comfortable in the dark, and rehearse every detail until it’s routine. Then trust the work when the sun goes down and the miles pile up.

Need a training plan built for your goal race? That’s what we do. Reach out to the Without Limits coaching team and let’s get you to the start line ready.

Why Your Sore Tendon Needs Load, Not Rest

If you’ve ever felt that deep, nagging ache in the back of your heel, the one that’s stiff and sore for the first few steps out of bed and then warms up once you get going, you’ve met tendinopathy. And if your instinct was to stop, rest it, and wait for it to heal, I understand why. It’s also the single most common mistake I see athletes make.

I have worked through tendinopathy myself and completely resting it, will do NOTHING to heal a tendon.  Careful and progressive loading is what the tendon actually needs to rebuild. Here’s why, and how to think about it.

Rest Feels Right. It Also Doesn’t Work.

A muscle strain and a cranky tendon are different problems. When you rest a tendon completely, it doesn’t come back stronger. It gets less capable. The tendon loses the very capacity you need to run pain-free, so when you return to training, the same loads that irritated it before now land on a weaker structure. You feel better for two weeks off, then you’re right back where you started within days of running again. Sound familiar?

Tendons are living tissue that adapts to the demands you place on them. Take the demand away entirely and they detune. The fix for an under-capacity tendon isn’t less load. It’s the right load, applied in the right order.

How Load Actually Repairs a Tendon

Tendons respond to mechanical loading by remodeling. When you load a tendon in a controlled, progressive way, you stimulate the cells inside it to reorganize and build, gradually increasing the tendon’s stiffness and its ability to store and return energy. Over weeks and months, that’s what raises your pain threshold and your performance ceiling at the same time.

The keyword is progressive. You’re not trying to blast the tendon or push through sharp pain. You’re giving it a reason to adapt, then a slightly bigger reason, then a bigger one, staying just ahead of where it is without overwhelming it. Think of it the way you’d build mileage: you don’t jump from 20 to 50 miles a week, and you don’t fix a tendon by going from zero to plyometrics.

The Loading Ladder

Rehab research generally moves a tendon through stages, from least demanding to most. You climb the ladder as pain and capacity allow.

Rung one: isometrics. These are holds. You contract the muscle and load the tendon without any movement at the joint, like rising onto your toes and holding, or pushing against something that doesn’t move. This is the smart on-ramp when a tendon is irritable, because you can load it meaningfully without the stretch-and-shorten cycle that tends to aggravate it early on. You get to start building capacity right away instead of waiting.

Rung two: heavy slow resistance. Once you tolerate holds, you progress to slow, heavy, full-range strength work, calf raises through their full range with real load, moving slowly up and down. This is where a lot of the meaningful tendon remodeling happens, and the evidence base here is strong.

Rung three: energy storage and release. The final rungs reintroduce speed and spring, hops, bounding, and eventually the running-specific loads your sport demands. This is where the tendon relearns to act like the spring it’s supposed to be. You don’t get here first. You earn it.

A Straight Answer About Isometrics

Isometrics got popular a few years ago on the back of a widely shared finding: a 2015 study of athletes with patellar (knee) tendon pain found that isometric holds produced a large, immediate drop in pain.1 That’s a real result, and it’s why you’ll hear coaches talk about isometrics as a pain-relief tool you can use even in-season.

But here’s the honest part, and it matters because so many of you are dealing with the Achilles specifically. When researchers tested that same immediate pain-relief effect in people with mid-portion Achilles tendinopathy, they didn’t find it. In a trial of 91 patients, isometric calf holds produced no meaningful immediate pain relief compared to other approaches, or even to rest.2 The dramatic painkiller effect that made isometrics famous shows up more reliably in the patellar tendon than in the Achilles.

So don’t do your isometric holds expecting the ache to vanish on the spot. That’s not why they’re on the ladder. They’re there because they let you start loading a grumpy tendon safely and begin rebuilding capacity from day one. The pain relief, when it comes, comes from the weeks of progressive loading that follow, not from a magic hold.

That distinction is the whole point of doing this honestly. Isometrics are the on-ramp, not the destination.

Let the Tendon Tell You Where You Are

The reason I don’t hand athletes a rigid day-by-day tendon protocol is that tendons don’t read calendars. They respond to load, and the tendon itself gives you the feedback you need if you’re paying attention. Two rules I coach:

Use a pain scale, and stay in the acceptable range. Some discomfort during loading is okay for a tendon; sharp or climbing pain is not. A common guideline is to keep pain at a low, tolerable level during and right after the work, not pushing into the range where you’re wincing.

Judge by the next morning. The real test isn’t how it feels during the exercise, it’s how the tendon responds over the next 24 hours. If it’s calmer or the same the next morning, the load was appropriate. If it’s noticeably more irritated and stiff, you asked for too much, and you scale back the next session. That morning check-in is your traffic light: green to progress, yellow to hold steady, red to back off.

This is exactly how I’m managing my own Achilles. I’ve been using an AlterG anti-gravity treadmill to control the load precisely, dialing body weight up as the tendon earns it, and reading that next-morning response to decide each day’s dose rather than forcing a predetermined plan. Progressive, responsive, patient. That’s the game.

The Bottom Line

Your sore tendon isn’t asking you to stop. It’s asking you to load it intelligently: start with holds to get on the ramp, build through heavy slow strength, and earn your way back to speed, all while letting the tendon’s day-to-day response set your pace.

Rest might quiet the pain for a week. Load is what rebuilds the tendon. Respect the difference, climb the ladder in order, and you come back not just healed, but harder to break next time.

Dealing with a nagging Achilles or a cranky tendon and not sure how to load it? That’s exactly the kind of thing our coaching is built for. Reach out and let’s build you a plan that fits where your tendon actually is.

This article is educational and reflects current research on tendon rehabilitation; it isn’t a substitute for individualized assessment. If you have persistent or worsening tendon pain, get evaluated by a physical therapist or sports medicine professional.

Footnotes

  1. Rio, E., Kidgell, D., Purdam, C., Gaida, J., Moseley, G. L., Pearce, A. J., & Cook, J. (2015). Isometric exercise induces analgesia and reduces inhibition in patellar tendinopathy. British Journal of Sports Medicine, 49(19), 1277–1283. ↩

  2. van der Vlist, A. C., van Veldhoven, P. L. J., van Oosterom, R. F., Verhaar, J. A. N., & de Vos, R. J. (2020). Isometric exercises do not provide immediate pain relief in Achilles tendinopathy: A quasi-randomized clinical trial. Scandinavian Journal of Medicine & Science in Sports, 30(9), 1712–1721. ↩

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