The Knowledge by Wahoo

Riding at Altitude Part 1 - What to Expect and How to Manage

Episode Summary

Hosts Dr. Jinger Gotschall and Mac Cassin dive into the basics of altitude. The Definition, long-term responses, short-term responses, submaximal and maximum intensities. And then finally, a few strategies for training.

Episode Notes

 Live High and Train Low? In this episode hosts Dr. Jinger Gottschall and Mac Cassin dive into the basics of altitude. The Definition, long-term and short-term responses, submaximal and maximum intensities. And then finally, a few strategies for training. From Sea Level to the Death Zone we help you understand Altitude in order to train and race effectively. Enjoy it! It's Nice! 

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Episode Transcription

Jinger Gottschall  00:02

Hey, welcome back to another episode of The Knowledge Podcast by Wahoo. I'm Dr. Jinger.


Mac Cassin  00:09

And I'm Mac Cassin. Today we're discussing the impacts of getting high.


Jinger Gottschall  00:13

Oh, wait,


Mac Cassin  00:15

what? In altitude is


Jinger Gottschall  00:17

Whoa, oh, okay, because we are in Boulder, Colorado, where that's totally legit.


Mac Cassin  00:23

It's high in that way. And also, you know, 1600 meters,


Jinger Gottschall  00:26

okay, right.


Mac Cassin  00:31

This is part one of a two part series about altitude. Today, we're really going to be diving into the basics of altitude, like definition, long term responses, short term responses, submaximal maximum intensities. And then finally, a few strategies for training. Part two will include more specifics about actually writing at altitude.


Jinger Gottschall  00:49

In terms of definition, sea level is anything less than 500 meters,


Mac Cassin  00:56

like 1500 feet for, since Neal's not here, we can use feet from time to time,


Jinger Gottschall  01:00

okay, from time to time, just so we have a little connection to the metric system in the US where we still use feet, low altitude, so this is still altitude, this is considered higher than sea level obviously, is 500 to 2000 meters. And that is getting into our definition of an altitude that can affect performance. And that's anything greater than 1500 meters, which lets us context again with Boulder Boulder is at about 5200 feet, which is 1600 meters approximately. So that gives you a little context. here in Boulder, we are at altitude, although in terms of the specific definitions, it's still a lower altitude,


Mac Cassin  01:46

right, because altitude goes all the way up to 8000 plus meters.


Jinger Gottschall  01:49

And what is 8000 plus meters


Mac Cassin  01:51

above 8000 meters is the death zone,


Jinger Gottschall  01:53

Death zone. So we've got a very large continuum, anywhere from 500 to 8000 meters above sea level, let's go back to this first category of altitude 500 to 2000 meters. And again, 1500 is when we start to see an effect not really an effect on your well being of sorts, but small reductions in performance that you can actually regain. If you're at that altitude for a longer period of time, around 10 days is really average, some people feel improvements as soon as six, and that's called being acclimated a moderate altitude is somewhere between 2000 and 3000 meters. And this is when you do start to feel emotional effects, you just may not feel yourself in terms of your mood. And there are reductions in performance and aerobic capacity that some folks actually never regain. Even if they've been at this altitude for long periods of time.


Mac Cassin  02:56

It's worth noting on that everyone reacts differently to altitude. And there's even been some good studies that show even the same person year over year might not react the same. So as we get into these impacts here, just understand that it's not a hard and fast rule for everyone.


Jinger Gottschall  03:14

Exactly. There's a lot of dependencies here, even on the acute line. And that could be as simple as how hydrated you are to how much how many carbohydrates you have in your system. If you're higher low in iron, again, we are giving general guidelines. So then


Mac Cassin  03:31

the next step up, you've got high altitude, which would be 3000 to 5500 meters. And this is where you can get acute mountain sickness, which would be dizziness, headache, muscle aches, nausea, you get a reduction in performance and aerobic capacity, and they're not restored by acclamation.


Jinger Gottschall  03:50

And just as a little interest in terms of if you are here in Colorado, this high altitude that Mac just mentioned, does include all of our mountain resorts, all of our ski resorts. So be aware, if you are coming from sea level and going directly to ski in Colorado, or Utah or Montana, then you're in this high altitude zone immediately and may want to be particularly aware of how to take care of yourself,


Mac Cassin  04:16

You'll get winded a lot faster at this point. And then extreme is you know, anything greater than 5500 meters, and that's where there's severe hypoxic effects. It's dangerous for many people to spend any amount of time at this and then again, you go even more extreme, above 8000 meters. The human body is actually not capable of living at that altitude because of the reduction in how much oxygen they can breathe. Which brings us to a very important part and one that I know is a bit of a pet peeve of yours. Yes and mine about there being less oxygen up here at higher altitude,


Jinger Gottschall  04:54

correct what we would love to be a result of this podcast is that no one who is listening ever says that there's less oxygen when you go to the mountains, or there's less oxygen in Denver, Colorado than there is in Tampa, Florida is the exact same. It's the exact same in all of these locations, the percent of oxygen is 20.93. That is across the board, so not less oxygen.


Mac Cassin  05:26

So then why do we say there's less oxygen? Oh, well,


Jinger Gottschall  05:29

great question Mac. It is because there are differences in barometric pressure that leads to a different partial pressure of oxygen. And we could go through from low to high altitudes and give you all of these numbers, but I'm just going to focus on to sea level and Pikes Peak. Pikes Peak is a mountain here in Colorado outside of Colorado Springs, that's 14,000 feet high, or 4300 meters,


Mac Cassin  06:01

you might know about it as from the Pikes Peak Hill Climb exactly a long and storied motorsport, that is crazy to watch. If you're in Colorado and ever get a chance, I would recommend it.


Jinger Gottschall  06:11

Absolutely. There's also a run as well as a ride. First to the top, the marathon actually is a half that you just go up. Or if you wanted to do the full then go ahead and blow your quads out and come right back down. Alright, so let's get back to it barometric pressure at sea level is 760 millimeters of mercury at Pikes Peak, when we're at 14,000 feet, it's down to 430 millimeters of mercury.


Mac Cassin  06:41

Yeah, and it's measured this way. Because you think about how much of the air stacked above it is pushing down which forces it's kind of like a you pipe and forces Mercury back up the other side where they can then measure it. So as the pressure increases, there's more pushing down so that mercury can travel higher up the tube for measurement. And as there's less pressure, it's obviously not going to come up as high. So it's a weird unit to get your head around. But that's the basics of it. But


Jinger Gottschall  07:11

think pressure, which is why Mack was saying pushing down. So that's barometric pressure. Now, this is then going to cause changes in the partial pressure of oxygen at sea level, the partial pressure of oxygen is 159 millimeters of mercury. And at Pikes Peak, it's down to 90. So that is the difference that we feel from 159 to 90 in terms of the partial pressure of oxygen, that means there's reduced pressure in the air, which is going to lead to a reduced pressure in the lungs, your blood and the tissues such as muscle, that's then going to limit exercise performance.


Mac Cassin  07:55

Yeah, you can kind of think of it like if you have a tube of toothpaste, if you can imagine the toothpaste coming out as the oxygen being forced into your lungs, if you squeeze harder, more is going to come out and more is going to be pushed through. And so with less pressure, it's not not getting as much stuff forced down. And so because pressure is the main driver here, the partial pressure is calculated, basically you take the percentage of oxygen divided by that hole. So the hole at sea level 760 millimeters of mercury 21% of the oxygen, so then 159 of that 760 is from oxygen. So that's what we mean by partial pressure of oxygen. Now there's two ways you can adjust that we just explained how changing the barometric pressure can alter that, you can also change that partial pressure of oxygen by altering the percent concentration of oxygen in the air. So when they do hypoxic training, there's two methods. One is to decrease the amount of oxygen in the air actually have less oxygen in the air, bring it down to like 16%, that reduces the partial pressure or you can get into a basically a pressure chamber reduce the pressure and you'll get that same the actual same mechanism as going up in elevation do different ones. The pressure one is a bit scarier, because you're putting yourself in basically a pressure chamber and fiddling around with things. But interestingly, there's some studies that show that the partial pressure at the lungs can be you can get the same result either through pressure or changing the percentage of oxygen, but then the actual partial pressure at the tissue level is different. And it's only significantly different with the pressure variation. That's a newer thing that probably needs a bit more validation and looking into but it's just interesting that even though at the base level, you can change this same metric, this partial pressure of oxygen in two different ways. But the only one that really makes a significant difference at the muscle tissues is pressure related.


Jinger Gottschall  09:53

Exactly. And so when we get into these specifics about how to train for it, that's just Something to keep in mind and think about where you live versus where you train, which is going to be a cool thing that we get to at the end of this episode. And


Mac Cassin  10:09

so when we talk about your aerobic exercise performance being impacted, it's really the hypoxic conditions of altitude, less partial pressure of oxygen. So your VO two Max goes down, which you know, means all the other metrics that sit below that like functional threshold power endurance base, you have less oxygen at those intensity, so you have less power on the anaerobic side, it's actually not initially directly affected.


Jinger Gottschall  10:34

Right, so we're talking here about how you feel or how your performance is affected in the first two days of being above 1500 meters.


Mac Cassin  10:43

And the reason that anaerobic power isn't really affected is because it's anaerobic, you don't derive most of that energy from oxygen. So that instant phosphocreatine, release, all that stuff is still functioning normally, right? The difference, though, is that your ability to recover from those efforts will be impacted. So I again, when you hear a lot of writers talk about when they raise up at elevation, they say like I can, I can't go into the read, because then I'll be kind of screwed for the rest of the day. It's yeah, because their ability to recover from that it takes it takes longer,


Jinger Gottschall  11:14

right. So although your anaerobic capacity may not change, your recovery may be longer, in addition to these basics about aerobic versus anaerobic being non affected, you will definitely feel some initial pulmonary ventilation increases, meaning your breath rate will simply be higher. And that's because you've got a lower partial pressure that's stimulating these chemo receptors within the cardiovascular system, and you have this greater tidal volume and breath rate. So it can be a bit uncomfortable. What this leads to is a hyperventilation, your blood pH is going to increase, which means it becomes less acidic. Exactly. So it's more basic, and you are blowing off more co2 than you usually would. The oxygen diffusion into your muscle decreases because of this decreased partial pressure, which is going to lead to this decreased aerobic capacity.


Mac Cassin  12:18

Yeah. And then, in addition to that, you'll get a decrease in plasma volume. Because a lot of it's due to water loss from breathing more, you're breathing more frequently. And it's generally quite dry at higher altitudes. So you are going to lose more water, you're going to have increased urine production, which all those things actually will increase your hematocrit, which is really just a measure of number of red blood cells proportionate to total volume of blood. So that sounds good at first. But if it's because of a loss of plasma volume, that's not the best, like we said dehydration, and then appetite loss can be a significant factor here as well. Again, if you're not eating properly, you're not going to train Well,


Jinger Gottschall  12:54

no. So there are a couple things that you can do when you have those first couple days at altitude, which would be to simply drink more. And also be very aware about your iron intake with respect to the foods that you're eating red meats, spinach, staying a little lower on the vitamin C, high fruits, those things will also help what Mac mentioned about plasma volume decreases, is also going to cause this chain reaction in terms of other cardiovascular variables, such as a decreased stroke volume, which is because of that reduced plasma volume that increased ventilation often goes hand in hand and also leads to an increased heart rate together, these two actually are going to cause an increase in cardiac output and oxygen consumption for a lower intensity. So that's why you feel you are going harder, and not necessarily producing as much power on the bike or running as fast, you do also get a greater utilization of carbohydrates for energy. So that goes back to Mac's suggestion about that maintaining your food intake. And even though you have a reduced appetite, and there's also an increase in the anaerobic metabolism, which is going to lead to increased lactic acid production and just leads to uncomfortable feeling sooner, depending upon that power or pace. And then


Mac Cassin  14:21

like we mentioned before, like 1500 meters is kind of this break point where vo two Max will start to decrease. Really, it's anytime you get that partial pressure of oxygen to be less than 131 millimeters. And that's again due to reduced arterial partial pressure and in a drop because again, that change in stroke volume. So you have a different Q max, which Why don't you tell us what Q max is q max


Jinger Gottschall  14:45

is cardiac output and that is the product of your heart rate and stroke volume.


Mac Cassin  14:50

There we go. And that will drop by eight to 11% per 1000 meters gained above that 1500 meter point. So do


Jinger Gottschall  14:58

you want to know a crazy fun act Mac


Mac Cassin  15:00

I, you know, I love a fun fact, oh, this,


Jinger Gottschall  15:03

this one really is crazy to me. There was a study done on Mount Everest, and it was called the Mount Everest descent in 1981. And individuals who had on average a vo two max of 60 mils per kg per minute, which is which is good, which is good. That's, that's actually in the top, we'll say 80% There vo to max at sea level, which was the in the 60 range went down to 15. And Mount Everest,


Mac Cassin  15:34

which is crazy. If you've ever been fortunate enough to be in a lab or seen anything, basically 15 is barely pedaling a bike, like hardly pedaling. So you'll hear if you ever hear someone explained going up Mount Everest or any other 8000 meter peak, they'll take a step and then need 30 seconds to catch their breath before they take another step. And that's just because they have no there's so little oxygen going into their muscles to use,


Jinger Gottschall  16:00

right. Just a quick little aside, I had my cousin Heather, and I'm sure she won't mind me mentioning this for her 50th birthday, she lives in New York, she wanted to climb a 14,000 foot peak in Colorado. So she came to visit I made us wait as long as we could, which is about day five into her visit. And we climbed one of the fourteeners. When we got to 1000 feet from the top, that's exactly what we did. But we did. We started at 100 steps. And by the time we got closer and closer, we had to reduce them to 20 at a time 20 steps, stop recover until we saw her heart rate go back down another 20 steps. So possible to do just be patient.


Mac Cassin  16:43

Yeah. And again, that's a good one coming from New York coming from sea level straight up here, you know, with with, you know, some time, maybe a few weeks, maybe three weeks up here, she could have maybe done a bit more than 20 steps. Exactly, exactly. And just as another fun anecdote, there was a high altitude study done here at CU one of the participants discovered to the study that his body was really good at dealing with high altitude, like he wasn't impacted nearly as much as other people. And so he started getting into doing super high altitude climbing. And that was, he wasn't interested in it before found out he'd be really good at it and started doing it. And it was very good at it. But again, that's just showing that some people just, they're a little different.


Jinger Gottschall  17:26

Exactly. And that actually leads to some research that was done on cyclists who were born at altitude, meaning born above 1500 meters, which doesn't include actually Boulder, Colorado and multiple large cities here in the US that they have a different response to these changes in altitude. Meaning I'm gonna say we because you and I were both born in the Denver boulder metro areas that were actually not as sensitive. So we can actually go to these higher altitudes. Without having such a severe response. The alveoli within actually our lungs are slightly more stratified, which gives us a better ability to deal with altitude. I'm not trying to brag, but I am.


Mac Cassin  18:14

So what you're saying is when you're when your customers hear you, you could have on 20 steps


Jinger Gottschall  18:19

I haven't could have done at least 21. All right, that takes us now into long term responses to sub maximal exercise intensity. And this means that you've been at altitude for about three weeks. So what can we expect if you've been acclimated for 21 days?


Mac Cassin  18:42

Yeah, so the big one, and probably one that most cyclists know something about due to the deep, dark doping past of professional cycling, you get an increase in red blood cell count through basically your body's production of EPO, which is released from the kidneys and that and that's your body's response to its senses, there's less oxygen available, so it wants to increase the number of little transporters that you have for for that oxygen, your cardiac output increases at rest and at submaximal exercise due to increase stroke volume, so you gain back some of that stroke volume, and then your muscles become better able to extract more oxygen, which further reduces the demand on cardiac output.


Jinger Gottschall  19:22

All crazy cool things that happen in less than a month,


Mac Cassin  19:26

and all things that will undoubtedly help you perform better


Jinger Gottschall  19:30

Exactly. If you therefore have the ability to spend a longer period of time at altitude before race, then a three to four week pre period is recommended. We're going to finish this episode up with talking about some things to think about with respect to the environment, as well as strategies for competing at altitude. And the couple things I want to mention about the environment is that the air temperature is much cooler. Willers, so your risk of cold related disorders increases, there is also very low humidity, so it's colder air with very little water. And therefore the dehydration, the skin issues, the dry throat, the kind of painful burning in the lungs are all going to be much more prominent.


Mac Cassin  20:19

If you were to come up to Colorado, your best bet would be to either compete as soon as you get here or train here for a few weeks, and then continue, there's a weird middle ground in there where you'll have all the negative effects just piled on top of each other and none of the adaptations. So that's why a lot of people who do compete a high altitude if they're not able to do any training camp before they'll get there as close to the event


Jinger Gottschall  20:43

as possible. Yet, it's tricky if basically we're saying, if you are here, anywhere from 48 hours to 20 days, that's a painful time period with respect to your acclimating to the current conditions. Yeah,


Mac Cassin  21:01

like we said, those like the respiratory rate, all that stuff, your body, it takes a while for your body to fully register, the higher altitude. So you can kind of cheat the first day because your body hasn't realized what you've done. But once it does realize it'll, it'll hold you back. And then with that, on the training side, the best thing to do is, is what we call live high and train low. So what is in this contents? What does that mean?


Jinger Gottschall  21:27

First of all, I just love the saying, that's another thing that would be cool to take away from this episode, live high train low, which basically allows you this passive acclamation to altitude, if you are living high, but then your training intensity, your power output, your pace is not compromised by the low partial pressure of oxygen during training, if you're actually training low. So if you can pull that off, and some people have done this acutely, by living low, but going to bed, in a chamber that is going to cause this hypoxic condition, right.


Mac Cassin  22:11

And so this is something that we've done a lot here living in Colorado, and when we when I'd go down and compete at sea level, it was very noticeable if you'd put out more power. So for me, if I did a stage race or something after the first day, my legs would just be destroyed, because you could go that bit more harder, and like repeatedly hard. So we'll do would do a lot of intervals on supplemental oxygen. So basically, like what you'd get at a hospital and oxygen masks do that, well, doing really hard intervals. It's a great way to absolutely destroy yourself. But it's one of those things that is kind of a necessary evil. I had I was going to be competing at sea level.


Jinger Gottschall  22:48

But I couldn't go down to mimic those conditions when you're training.


Mac Cassin  22:51

Yeah, exactly. And then, like ginger, saying that people can do that the opposite lived down at sea level, but then be in a chamber, it's worth noting for that to work, you need to be in that chamber for like 14 hours a day minimum, right. So it's not just eight hours of sleep to bed, it's and so I know, Ron Dennis, when Neil was working with him to prep for the hour, he couldn't get to altitude. So that's what he did. And he wasn't there, like that many hours each day, because


Jinger Gottschall  23:16

brutal what we will do in terms of maximizing performance. We have one other interesting recent research tidbit, which is about the fact that a lot of research has been done on how to improve your feelings based upon nutrition components. And because you have that reduced appetite and poor energy availability, and therefore decreased iron levels, the best way is actually to eat foods that are going to increase these levels and not take a bunch of supplements. So don't hop on the plane when you go to altitude and have all of these pills that you think will help you with these adaptations. They're not as effective as actual real nutrient dense foods.


Mac Cassin  24:06

I think that's probably a good tip just in general is if you can aim for getting all the vitamins and minerals you need out of actual food and not not pills in a bottle.


Jinger Gottschall  24:15

Totally. I'm definitely for that. So this was such a blast and giving us our altitude 101. And as a refresher anything above 1500 meters is considered altitude and that is causing a reduced partial pressure of oxygen in the air and that is what will influence your lungs blood and muscle tissue limiting your performance and Mac what tell me the difference in terms of the percent of oxygen at sea level versus Boulder, Colorado versus Mount Everest.


Mac Cassin  24:51

It is exactly 0% different.


Jinger Gottschall  24:54

Oh gosh, he is so brilliant. You are totally listening.


Mac Cassin  24:58

Yes, always the same amount. have oxygen, it's just not being pushed into your lungs as hard. And so with that aerobic exercise performance is going to be most affected by a hypoxic condition so that high altitude anaerobic performance isn't as impacted however, recovery from anaerobic performance will be less enjoyable.


Jinger Gottschall  25:17

Exactly. And finally, when possible, live high and train though you're gonna get the best of both worlds with respect to the adaptations from altitude and the ability to maximize your performance at sea level.


Mac Cassin  25:31

Well, that's it for another episode. We hope you're able to take away some useful information for the basics of getting high and that it will help make you a better endurance athlete. Thanks for listening to the knowledge podcast by why not you