Trekking to Everest Base Camp

Ben Valsler speaks to Laura Soul about how her body responded to her trek up to Everest Base Camp, including exerts from her audio diary...
18 October 2009

Interview with 

Laura Soul


Everest Trek - Lukla


Ben -   While Laura was on her high altitude adventure, she decided to monitor what happened to her body by doing a series of experiments on herself and on her brother (who wasn't always the most cheerful volunteer).  She measured heart rate, blood oxygen content, urine pH, and her sense of smell.  She also recorded an audio diary for us.  I caught up with her once she got back into the country to find out just how her experience had been...

Laura -   It was actually a really amazing experience.  I really enjoyed myself. It was hard work, it took a very long time, but it was definitely worth it.

Ben -   So first of all, how high is Everest base camp?

Laura -   Base camp itself is at 5,300 meters, but the highest we went while we were going up there was 5,450 meters.

Ben -   So, although it is called base camp, people shouldn't be fooled into thinking that it's at the bottom of the mountain.

Laura -   No.  It's certainly very high up, especially compared to where we live here at Cambridge which is sea level.

Ben -   Well, let's have a listen to the first part of your audio diary.

Everest Trek - LuklaLaura -   We've now arrived in Phakding which is at 2,652 meters.  Some of the views up here have been absolutely spectacular.  You can see the deep gorges and the high rising peaks, typical of the Himalayas.  Unfortunately, for a lot of the day, it's been quite cloudy and has been raining fairly solidly all day which is a shame.  But we've still being able to see a lot and it's been an amazing experience.  This morning we flew in via a two propeller plane into Lukla.  It was a fairly terrifying experience.  The runway is 60 meters higher at one end than the other, but it has to be because it's so short.  It has to slow the plane down by going uphill.  Lukla's at 2,800 meters and Phakding's at 2,652 meters so we're arriving higher and sleeping lower which is the recommended course that you take when you're going to higher altitudes, to allow you to acclimatize to the altitude more effectively.  At this height, I haven't noticed that much difference.  You are a bit more out of breath as you are climbing uphill.  But other than that, everybody seemed fine.

Ben -   So, although you are at altitude, it doesn't sound like you're really feeling any of it.  Did your experiments show any physiological changes?

Laura -   Yes.  They actually did.  Even though we didn't necessarily notice the change ourselves.  Oxygen blood level had dropped down to about 97% of what it normally is and our resting heart rates had increased by maybe 10 or 20 beats per minute.

Ben -   So there are certainly physiological effects already, but it sounds like it's not really stopping you from moving on?

Laura -   No.  Not at all.  I mean, it's hard work.  It's a hard walk, but you take it so slowly to try and prevent altitude sickness.  No, we weren't feeling anything at that stage.

Ben -   Okay.  Let's have a listen to the next stage of your walk.

Laura -   Today, we walked from Phakding to Namche Bazaar which is at 3,446 meters which means an increase of 794 meters.  The climb was pretty steep the whole way and it was quite tough.  What was perhaps most disconcerting was that sherpas often happily walked past us, having no trouble at all when they were carrying up to 80 kilograms sometimes.  We've now started to see the effects of altitude.  You do get more out of breath doing things.  It is harder and you are more tired.  By the end of the day, the whole group pretty much was completely exhausted.  However, nobody is ill yet.  Everybody is feeling well and happy and is looking forward to our rest day which allows us to acclimatize to the altitude tomorrow.

Ben -   Now that sounds like that was an enormous change in altitude in one day.  Seven hundred ninety four meters.

Laura -   Yes.  It really was a big jump up that day and it was quite hard work and you really saw it in the experiments that we were doing.  My blood oxygen level had dropped down to about 90% of what it normally is which is quite a big difference.

Ben -   But by the sounds of it the following morning, you really got a glimpse of what it was that you were aiming for.

Everest Trek - LohtseLaura -   This morning, as we left Namche Bazaar, the sun was out and we got our first glimpse of Mt. Everest.  Unfortunately, it did only last for about 5 minutes before acloud came across, but we could still clearly see Lhotse, the mountain next to Mt. Everest which is also higher than 8,000 meters.  The morning's walk was quite flat.  There weren't really very many up or down sections and the sun was out which made it quite pleasant.  However, after lunch, the rain set in and we had to walk up a steep hill for about two hours.  A few people were starting to get headaches, me included, but nothing that an aspirin couldn't get rid of.  We've now reached Dingboche which is the cultural and religious centre of the Khumbu region.  Dingboche is at 3,810 meters which is an increase of 364 meters from Namche Bazaar where we were staying last night.  This is a relatively small jump compared to some of the other ones that we've done.  However, as you get higher, the tougher each small jump becomes.  The one thing that we are all noticing is that we tire out a lot more quickly than usual.  There's less oxygen up here which makes everything a lot harder work.

Ben -   So, even though the altitude change is a lot smaller than the previously walk, it sounds like it's getting a lot harder.

Laura -   Yes.  It definitely was.  We were really beginning to feel it.  And that afternoon in particularly, when the weather set in and we were essentially walking up steps on what was almost a vertical cliff phase, it was very much hard work.

Ben -   And your experiments reflected this increased effort?

Laura -   Yes.  Again, as Andrew Murray suggested, oxygen levels were dropping right down and our heart rates were shooting up again.

Ben -   But the tough climbs don't stop there.

Laura -   Today, we stayed in Pheriche again.  But to try and prepare us for the rest of our journey, we had an acclimatization day which meant climbing up a nearby hill which went up to 5,100 meters.  Probably about halfway up, I started getting quite a bad headache.  We had the option of going to about 4,900 or carrying on for the final 200 meters and quite a few people, me included, stopped at 4,900.  We'd been told that a headache doesn't really matter as long as it stays at the front of your head.  It's when it goes around to the back of your head, that it becomes dangerous.  Also, according to our guide Zanger, it's all about your mental attitude.  The more you worry, the more you stress, the more you think about things while you're walking, the more likely you are to get headaches, to feel nauseous, to get altitude sickness in general.  And although I do have a very bad headache now, I have to say that having taken his advice so far, it usually does seem to work and is certainly a lot easier to sleep.

Ben -   So, Andrew Murray was saying that sleep would be interrupted because of this strange breathing pattern.  Did people start to experience that?

Laura -   Yes.  At this stage, there were a lot of people commenting that they were having trouble sleeping, that they kept waking up in the night, and they couldn't work out why.  And actually, when you could hear the breathing patterns of people nearby you when they were sleeping, you could definitely notice that there were these short little breaths and then the large gasping breaths, and then their breathing would just cut-out completely which was a bit scary, but it was really interesting.

Ben -   And it sounds like trying to relax and not think about it really helped.

Laura -   Yeah, I really found that just letting my worries float away and not thinking about anything really made me feel a lotbetter.  I mean it's part of the Nepali philosophy, just everybody chill out and relax.

Ben -   So, with that in mind, you got your heads down, thought about nothing, and carried on walking.

Laura -   So today, we've walked up to Lobuche which is at 4800 meters.  It was a very tough climb despite the fact that we had the acclimatization day the day before.  I think having pushed myself quite hard yesterday, it's left me with a headache today, especially because I've been worrying about it.  The other things is, up here, it's suddenly noticeably colder for the first time.  Other people are really starting to feel the effects of altitude as well, more and more of the group are getting headaches, although no one's had any serious problems yet, thankfully.  One thing people are definitely noticing is that you have to go to the toilet much more than you usually do and it's a lot harder to sleep.

Everest Trek - Valley ViewBen -   So, just as predicted, you had to go to the toilet far more often.  And this, Andrew Murray was saying, is to do with balancing your body's pH.  We're you able to do any experiments to prove this?

Laura -   Yes.  We actually did measure the pH of our urine and there was quite an interesting effect.  Whereas with your oxygen level and your heart rate, there's sort of a steady increase and decrease while you're travelling.  With this, it was more that the alkalinity of urine would shoot up when you made a jump in altitude, when you went up a long way, and then very quickly, it would drop back down again to a normal level.  And then as you went up again, it would shoot back up and then drop all the way down again.

Ben -   Fascinating stuff.  You are in many ways very close to reaching base camp.  We will find out later in the show if you actually made it.  By this point, the views must have been incredible.  And there must've been quite a drive to get there.

Laura -   Yes.  It really is a spectacular place.  If anyone ever gets a chance to go there, I'd recommend it.  I've never seen like it before in my life and I'd love to go back.


Ben -   Now, we go back to Laura Soul to find out if she made it all the way up to Everest base camp.

Laura -   Yes, we did.  Everybody in the group got all the way up there.

Ben -   How did you feel when you got there?

Laura -   Immediately when I got there, not that great because it was very difficult to get up there on that day.  It was a very long walk.  We'd been walking all day by the time we reached base camp.  So, I was exhausted, I had a splitting headache and I just wanted to lie down on the floor really.  But once you'd got over your initial exhaustion, you could stand there and look around you and sort of take in what you'd achieved and just look at what was around you to.

Laura -   It's good to sit down.  I have a massive headache and so do most people.  I felt a bit sick on the way up, but I'm okay now.  Some people feel very sick.  The view from here is absolutely amazing.  You can see the Cumbu ice fall which is really beautiful with these huge big jagged peaks of ice.  It's been very hard work to get up here but I'd say that it was definitely worth the climb.Everest Base Camp - Laura Soul

Ben -   Well you do certainly sound exhausted, but that must be a day that will stick in your memory forever.  But thinking back to the experiments you were doing on yourself, what was your heart rate and blood oxygen like that day?

Laura -   Well it had really dropped down then.  I mean, my oxygen level was 79% of what it usually is which is very low and our heart rates were also above 100, above 110 in some cases.

Ben -   And how long did you actually manage to stay there?  How long did you stay at base camp?

Laura -   I think we were probably there for about an hour or an hour and a half in total.

Ben -   And it must have felt nice to start coming back down.

Laura -   Yes.  When we began descending, it was quite a relief.

Laura -   We're back down at Namche Bazaar now at 3,440 meters.  My blood oxygen level is back up to 94%.  The difference between how I felt on the way up here and how I feel now on the way down is absolutely huge because I have acclimatized to higher altitudes.  So now, it's easier to breath here than it was on the way up.  Everyone is just really full of energy.  Even though we walked in one day, what took us four days on the way up.

Ben -   Well, thinking back to what Andrew Murray was saying earlier and the experiments that you've done, one thing that we haven't talked about yet is the sense of smell.  So what happened?

Laura -   So yes.  I definitely noticed that my sense of smell wasn't as good particularly because I couldn't smell myself or any of my trekking companions, nor could I smell the many yaks that were there.

Ben -   How do you go about measuring your sense of smell?  Surely, it can't be 'stand a certain distance from a yak'?

Laura -   No, unfortunately.  Well I used the University of Pennsylvania's smell identification tests, that we got from a company called Sensonics. So basically, it's four little booklets and they're kind of a scratch and sniff type things.  So you go through with a pencil, scratch them off and you choose which thing you think it smells most like. Basically, the more that you get right, the better your sense of smell is.  I've got one here actually, if you want to have a smell and some of them are quite potent.

Ben -   So, this really is just a little scratch and sniff booklet.  We have to scratch it with a pencil.  I'm being told that this odour should smell like lilac, chilli, coconut, or whisky.  So I'll give it a scratch.  I actually find that quite hard to tell.  It could be lilac or it could be coconut.  What does that tell me?  How do I use this scratch and sniff to tell me how good my sense of smell is?

Laura -   Basically, you cross off the answer that you think it smells most like with the tests they give you and then a booklet that tells you the actual answers, what it's actually supposed to smell like.  So, if you've got it right, then you got a point and then the more points you get, the better really.

Ben -   I assume they aren't all pleasant things like lilac and coconut.

Laura -   No.  Sadly, some of them are quite unpleasant.  There's onion, there's motor oil, there's paint thinner.  It wasn't a pleasant experience completing these halfway of a mountain.

Ben -   All in the name of science and we did find evidence to back up what Andrew Murray was saying that your sense of smell appears to decrease with altitude.

Laura -   Yep, definitely.

Ben -   So, it was obviously a fantastic experience.  Did everybody else that you climbed with enjoy it as much as you did?

Everest Trek - LobucheLaura -   I think in the end, everybody probably enjoyed as much as I did but there was a very wide variety in the way that people responded to going up that high.  To find out how some of the others had felt, now that we were further back down after we've been to base camp, I first of all spoke to Nikki Scott.

Nikki Scott -   I am feeling a lot better.  You can definitely tell that there's more oxygen even though we're still over to the half thousand meters above sea level.

Laura -   Did you notice any difference in your sleeping pattern?

Nikki Scott -   Generally, I slept quite well, but yeah, definitely I was going back and forth to the bathroom a little bit more.  But apart from that, I was actually okay with altitude.

Laura -   Nikki actually got off very lightly but not everyone was so lucky.  I also spoke to Steph Shay.

Steph Shay -   Basically, the whole way up, I had a slight headache and the higher up we got, the worse the headache got, to the point where, yeah, I couldn't function that well.  Going to the bathroom, I needed to pee a lot more than usual.  Another thing that I did find was when I was trying to sleep, I found it really hard to breath.  I had a really heavy chest, tight chest.  I think that was about it - I got sick, stomach sick.  Probably yeah brought on by altitude as well.

Ben -   So a real variety of reactions but I'm guessing that everybody was equally thrilled with the experience.

Laura -   Yes, definitely.  I think everyone certainly felt that it was worth it and a few people raised a lot of money for charity as well. In fact this sort of adventure makes people feel charitable and I'd like to say thank you to Sensonics who gave us the smell identification tests, pH health who gave me the urine alkalinity testing sticks and also to Proact Medical who lent me the pulse oximetre for my trip.


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