Eight days around the back of Torres del Paine under a heavy pack, everything she needed on her back, and she felt strong the whole way. That is the part worth sitting with before anything else. The trek was not where this went wrong.
That was one of our team on the full O Circuit. Her pack came in around 35 pounds, which she will freely admit is heavy, because she went self supported and every day of food rode with her. She used trekking poles from the first morning to the last. She is a genuinely fit person who trains regularly, her legs are far and away the strongest part of her body, and she had rucked before the trek. She had also already done Everest Base Camp and the Inca Trail, both of them with a porter carrying the gear, so this was the first time she had walked a multi day route with her whole life on her back.
She came off the circuit fine. Tired in the normal way, sore in the normal way, no knee pain at any point, over the John Gardner Pass and down the other side.
Four or five days later, she was in El Chaltén, Argentina, for the Laguna de los Tres hike. She had walked that exact trail two years earlier and it had not bothered her in the slightest.
The day the bill came due
Laguna de los Tres is a long day rather than a hard one for most of its length. Roughly 20 to 25 km round trip depending on your start point, around 800 meters of gain, eight to ten hours. The first stretch is a gentle walk. Then the last kilometer climbs about 400 meters up loose moraine, steep and rocky, and you come back down that same 400 meters of loose rock at the end of an already long day.
She was carrying a daypack. Nothing like the 35 pounds. And by the time she walked back into town her knees hurt worse than they ever had in her life.
They did not recover. She cancelled the hiking she had planned for the rest of her time in El Chaltén. Back home she saw a physiotherapist, ended up getting MRIs on both knees, and spent the next six to eight months in a structured knee rehab program. It was the first time her knees had ever hurt.
What actually happened
Nothing dramatic. There was no fall, no twist, no single step that did it. Which is precisely why the story is worth telling.
And here is the detail that makes it useful rather than obvious: she had rucked. This is not the story of somebody who skipped the load work. She had trained with a weighted pack before the trek, more than once. She still ended up in rehab, and the reason sits entirely in the shape of that training.
Her rucking was scattered, not progressive. Occasional loaded walks build a little tolerance. What builds the kind that survives eight consecutive days is progression, the same session returning week after week with a little more weight or a little more time, because load conditioning compounds and scattered sessions never accumulate into anything your tendons can spend. Hers were whenever they happened, at whatever they happened to be.
Nothing around the rucking trained the up and down. This is the heart of it. A ruck on level ground trains carrying, and that is genuinely valuable, but it is only one piece. A trek is also thousands of loaded steps climbing, and thousands more braking on the way back down, hour after hour, and the braking half is where the damage builds without announcing itself. That work has to come from somewhere else: stair sessions, eccentric leg strength, loaded time on real hills. Her rucks stood alone, so her legs had carried weight but had never climbed or braked under it. The O gave her eight days of exactly that, then Laguna de los Tres finished with 400 meters of descent on loose rock.
The training never rehearsed consecutive days. A trek is not a hard day, it is a hard day repeated, on legs that started the morning already behind. For a fully self supported trip, the final block of training should include loaded days back to back, because starting day four on day three’s legs is a skill, and it is one almost nobody practices.
She skipped the boring bookends for eight days straight. No warm up. She would stand up in the morning, put the loaded pack on, and start walking. Almost no stretching or mobility work at the end of the day either. One day of that is nothing. Eight in a row is a pattern.
She trusted how she felt. Feeling fine on the trail was read as proof that the preparation had been adequate. It was proof that the trek was survivable, which is not the same claim.
Why the injury waited four days
This is the part people push back on, and it deserves a straight answer. If the trek did it, why did nothing hurt on the trek?
Because your tissues do not all adapt or complain on the same schedule. Muscle responds to new work relatively quickly. The tendons and connective tissue that hold a joint together adapt more slowly, and they tend to register accumulated overload rather than any single hard hour. Eight days of unfamiliar load did not break anything on day four. It spent down whatever reserve she had.
Then she added a very long day with a 400 meter descent over loose rock at the end of it, which is about the most demanding braking work a pair of legs can be handed. It landed on tissue that had spent all week absorbing more than it was built for, with no warm up and no recovery work.
Nothing failed on the pass. The accumulation failed, four days later, on the day that looked easy on paper.
And the trail itself is the cleanest evidence available here. She had walked Laguna de los Tres two years earlier with no trouble at all. Same person, same trail, same steep last kilometer, same rocky descent, same size of daypack. Two years is not enough time for ordinary ageing to turn a comfortable eight hour day into six months of rehab. What changed in between was the eight days of unfamiliar load she put through her legs in the week before she started walking.
The hike didn’t get harder. She arrived at it with nothing left in the account.
What the MRI actually said
Her imaging came back with a result a lot of adults get. Wear. The cushioning in the joint had thinned in the way it tends to over time. There was also a small tear on one knee, which was not treated as the main story.
Her own summary of the report was blunter than the radiologist’s. It basically told her she was getting older.
That finding does not let the pack off the hook, and here is why. Findings like these turn up constantly in knees that hurt not at all. A meta-analysis pooling 63 studies of asymptomatic, uninjured adult knees found cartilage defects in 24 percent of them overall, ranging from 11 percent in people under 40 to 43 percent at 40 and over, with meniscal tears in 10 percent overall on the same rising curve. A separate study that scanned 230 knees of pain free adults found an abnormality in at least one structure in 97 percent of them. None of those people had any idea, because nothing hurt.
The wear was not created on the O Circuit. It was already there, silent, while she trained, hiked, walked to Everest Base Camp, walked the Inca Trail, and felt nothing at all. What changed was that she asked a joint carrying ordinary adult wear to absorb eight days of a load it had never trained for, then handed it a 400 meter descent on loose rock while it was still catching up.
The wear set the ceiling. The untrained load is what put her through it.
This part matters beyond her story, because a scary sounding scan sends plenty of people to the conclusion that their trekking days are behind them. Her outcome argues the other way. Nothing on that scan reversed. The cartilage did not grow back. She got better by building strength around the joint over months, and she treks today with the same findings on file that she had when she could barely walk back into El Chaltén.
Being fit is not the same as being loaded
Two details in this story matter more than they look.
She used poles the entire trip. Poles are genuinely good, they share the braking work and reduce the force reaching the knee, and we recommend them constantly. They did not prevent this. They are a tool that reduces load, not a substitute for tissue that has been trained to handle it.
And her legs were strong. Strength in the gym is not the same as durability on the trail, and it is definitely not the same as durability under a pack for eight consecutive days, on uneven ground, with poor recovery, at a weight and a duration her training had not practiced.
Load is its own training variable, and training with a heavy pack is a system rather than a single exercise: a progressive carry, the climbing work, the braking work, and, for self supported trips, days repeated back to back. Rucking covers the first of those. Do it without the rest, and without progression, and you have trained a heavy walk. That is how a person who genuinely rucks still arrives at a self supported trek underprepared, and it is a far more common position than never rucking at all. Our own fitness check article puts it as a question worth asking honestly: can you carry your pack and forget it is there?
What she would do differently
Weigh the pack first, then build the training around that number. The training question for a self supported trek is not “am I fit.” It is “have I carried this specific weight, for hours, repeatedly, on ground like this.” Find out what you will actually carry before you plan your training, not the week before you fly.
Ruck on a progression, not on a whim. The magic is not any single session, it is the same session returning every week with slightly more in it. Progress toward your real trek weight, add time before you add weight, and give the whole build months rather than weeks if you are carrying everything yourself. This is the full case for rucking, and her story is the version where somebody did the sessions but never the progression.
Train the up and the down alongside the carry. The ruck builds the carrying. The climbing and the braking need their own work: stair sessions, step downs, slow lowering strength, and some loaded time on real hills where you can descend with the pack on. The descent is where treks collect payment, and a pack multiplies every bit of it.
For a self supported trek, finish with loaded days back to back. In the last few weeks before a trip where you carry everything, even two consecutive moderate loaded days teach your legs something a single weekly session cannot: how to work while still catching up from yesterday. Treks are made entirely of those days.
Do the boring bookends anyway. Five minutes of movement before you put the pack on. Some stretching and mobility at camp. It is unglamorous, it will not show up in any photo, and eight days without it adds up.
Treat “I feel fine” as information, not a verdict. Especially on a trek. Especially on the days near the end.
The uncomfortable part, said out loud
We sell a training plan, so it is fair to ask whether ours would have prevented this.
Honestly: what our 8-Week Trekking Fitness Plan is built around is precisely what her training lacked, and it is worth spelling out why, because the differences look small on paper.
The plan’s weekly ruck is deliberately on flat ground, and taken alone that might sound like what failed her. It isn’t, for two reasons. First, the plan’s ruck is progressive. The weekly sessions build from 45 to 75 minutes as the load climbs toward 16 to 18 percent of bodyweight, and by week eight a separate long ruck runs three to four hours at a lighter 6 to 8 percent. Progression is what turns loaded walking into compounding tolerance. Her sessions were scattered, so nothing ever accumulated. Second, the plan never asks the ruck to do the whole job. The climbing lives in the stair climber sessions, and the braking lives in the leg strength work, with its step ups, lunges, and controlled lowering. The ruck carries, the rest of the week trains the up and the down. Her rucks stood alone, so nothing trained either one.
For a fully self supported trek at 35 pounds over eight days, you extend the plan rather than replace it. Scale the ruck beyond the plan’s 16 to 18 percent toward your actual trek weight. Move some loaded hours onto real hills. And in the final weeks, put a couple of loaded days back to back. Any program that claims a fixed number of weeks prepares you for any pack weight on any trek is selling you something. The structure is the point. The specific number on your back is yours to train for.
The rehab, and the disclaimer
What eventually worked for her was not rest, and it was not a shortcut. It was progressive strengthening of the muscles and tendons around the knee, done properly and slowly, over months.
This is one person’s experience and it is not medical advice. We are not diagnosing anything, hers or yours. Knee pain that persists, or that arrives with instability or swelling, deserves a professional assessment rather than an internet article. She got one, including imaging, and that is what got her pointed at the right program. If your knees are talking to you, go and get looked at. Our general guide to knee pain in hikers covers the awareness side of it.
The honest lesson
She is fine now. She still treks, and she still rucks, more often and on better ground than she used to. The 35 pounds was heavy and she would pack lighter next time, and that is the smaller half of the lesson.
The bigger half is this. She was fit, she was experienced, her legs were strong, she used poles, and she had done loaded training. She still spent the better part of a year rehabbing knees that had never given her a problem in her life. The gap was not effort, and it was not ignorance of what rucking is for. Her legs had never been trained, progressively and as part of a system, to carry that much weight through long days of climbing and descending, repeated one after another, which is the entire job description of a self supported trek. Sessions are not a system. The system is what prepares you.
Your body does not grade you on whether you trained. It grades you on whether you trained for the specific job, and it can wait days after the finish line to hand back the mark.
Progressive load, descent strength, and the knee protection work that goes with them are built into our Trekking Fitness Plan from week one, with a video demo for every exercise and bodyweight alternatives throughout.
