Updated 10th July 2024

Can exercise in space help fight cancer on Earth?

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What do astronauts and people with cancer have in common? 

In today’s episode of ZOE Science & Nutrition, Jonathan is joined by Dr. Jessica Scott, who explains how 6 decades of NASA research is helping cancer survivors recover.

New research challenges the traditional notion that you should just rest during cancer treatment. Jessica’s studies into exercise could hold the key to a long and healthy life after diagnosis. 

Dr. Jessica Scott started her career at NASA, where she spent 7 years designing exercise programs for astronauts in space.

Now, as the principal investigator at the world-leading Memorial Sloan Kettering Cancer Center, she’s using her unique skills in the fight against cancer.

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Episode transcripts are available here.

ZOE Science & Nutrition

Join us on a journey of scientific discovery.


[00:00:00] Jonathan Wolf: Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.

Today, we learn how research from NASA is being used to combat the effects of cancer. NASA is often at the cutting edge of science. Since 1958, their groundbreaking research has helped unlock mysteries from our galaxy and beyond. But NASA's innovations aren't limited to astronauts and spaceships. In fact, Some of NASA's most important discoveries have benefited the whole of humanity here on Earth.

My guest today knows all about this. Dr. Jessica Scott spent seven years at NASA researching how exercise affects the health of astronauts during space missions. Now she's applying six decades of NASA research to the fight against cancer. At the world-leading Memorial Sloan Kettering Cancer Center in New York, Jessica investigates how exercise can alleviate the unwanted side effects of cancer treatment, which matters as there are over 18 million cancer survivors in the U.S. today. 

Her research challenges the idea that you must rest during cancer treatment. Using unique insights from space travel, Jessica wants to transform the long-term health of cancer survivors around the world.

Jessica, thank you for joining me today. 

[00:01:34] Dr. Jessica Scott: Thanks for inviting me. 

[00:01:35] Jonathan Wolf: So we have a tradition here at ZOE, where we always start with a quick-fire round of questions from our listeners. We have these very strict rules. You can say yes or no, or if you have to, you can give us a one-sentence answer. Are you willing to give it a go?

[00:01:50] Dr. Jessica Scott: Let's do it. 

[00:01:51] Jonathan Wolf: All right. Is space travel bad for your health? 

[00:01:54] Dr. Jessica Scott: Yes. 

[00:01:55] Jonathan Wolf: Which is not a question I've ever asked before, so this is definitely going to be a fun episode. Are there similarities between the side effects of space travel and the side effects of cancer treatment? 

[00:02:06] Dr. Jessica Scott: Yes. 

[00:02:07] Jonathan Wolf: Do cancer survivors have a greater risk of heart disease?

[00:02:11] Dr. Jessica Scott: Yes. 

[00:02:12] Jonathan Wolf: Is it possible to reduce the side effects of cancer treatment? 

[00:02:16] Dr. Jessica Scott: 100%. 

[00:02:17] Jonathan Wolf: And finally, and you can have a whole sentence, what's the most surprising thing you learned about human health from your time working at NASA? 

[00:02:25] Dr. Jessica Scott: I think the most surprising thing has been how important exercise is in preventing all of the side effects.

It's been critical. So without exercise, I don't think we would even be considering going on missions to Mars. 

[00:02:38] Jonathan Wolf: It's amazing. And I want to unpack that through this episode. I have to say that I've had the pleasure of speaking to a lot of scientists on the show with a very wide range of research areas. But I never expected on a show about health and nutrition to be discussing the work of NASA. 

So I'm really fascinated to see how that connects, given what you were saying in the quickfire answers. And especially because I'm not too proud to admit that when I was a child, I was a bit absolutely fascinated by space and astronauts.

So this is quite cool. Now, in my head, I'm thinking, you know, both as a child, but now I always imagined astronauts to be these super strong, super healthy individuals. So therefore I was like, well, why does NASA need someone like you to worry about making sure these astronauts are healthy? Surely they've been selected to already be perfectly healthy. 

[00:03:31] Dr. Jessica Scott: Yeah, I think that's a very common conception is that astronauts are these superhuman athletes. And in reality, they're just like you or I, there's a huge spectrum. So there are very, very fit astronauts. And then there are astronauts that do not enjoy exercising. 

So right now on the International Space Station, the average astronaut is a 49-year-old male, who has a cardiovascular disease risk factor. So they may have high blood pressure or high lipids or be overweight. 

[00:04:02] Jonathan Wolf: Ah, so I had in my mind that, you know, they were 25 and they could bench press me in one arm, but that is not the astronaut today. 

[00:04:12] Dr. Jessica Scott: That's not the average astronaut today. 

[00:04:14] Jonathan Wolf: So they exist, but that's not exclusive.

[00:04:17] Dr. Jessica Scott: That's not exclusive. It's not a requirement to get in to be an astronaut or be selected to be an astronaut, it is to be a superhuman athlete, you know, there's a lot of other requirements that are more important. 

[00:04:29] Jonathan Wolf: Got it. So how does going to space impact your health? 

[00:04:34] Dr. Jessica Scott: There are two main factors that happen when you go into space. So the first is what we call a direct hit. In space, you lose all of the gravitational flow that pulls your blood into your legs. So all of the blood goes into your chest and the head. And astronauts have what they call a puffy face syndrome.

So when you look at a picture of an astronaut on Earth versus in space, their faces look puffy, you can see some blood vessels that are distended, a little bit bigger, and that's because of all the blood that's starting to pool in their chest and their head.

And then the second factor is one that's a really big hit, and that's the fact that there are no steps of daily living on the International Space Station. So astronauts usually locomote by using their arms, They don't use their legs a lot. 

They have a different body shape when they're in space. Their backs are a little bit more curved. So they become very deconditioned. Their muscles get weaker, their hearts get weaker. They have changes in a lot of their cardiovascular function and bone health. 

So it's very damaging to go into spaceflight. And NASA has known this since the 1960s. 

[00:05:46] Jonathan Wolf: I never thought about it, but I'm thinking about the, you know, you're supposed to do 10,000 steps and you're saying they do no steps because there is no gravity and your legs are sort of, you're basically, almost useless is what you're describing.

[00:05:56] Dr. Jessica Scott: Exactly. It's basically like lying in bed. And that's how we use an analog of space flight as actually bed rest. 

[00:06:04] Jonathan Wolf: And we all know that lying in bed for an extended period of time is bad. And you're saying you could be in space for months. That's like literally lying completely static in bed for months.

[00:06:12] Dr. Jessica Scott: Exactly. Astronauts are in space for anywhere from six months up to a year. So you can imagine what happens to your body when you're lying in bed for that long of a time without any interventions. 

[00:06:25] Jonathan Wolf: So I guess your job was to think about those interventions and try and make sure that these astronauts stay healthy?

[00:06:32] Dr. Jessica Scott: That was part of my job because we were trying to figure out what is the best exercise program for astronauts. And it was actually really interesting that back in the 1960s, NASA noticed that astronauts were having all of these side effects. And instead of using a drug to try and offset some of these changes, I think some very forward-thinking clinicians and researchers decided to try exercise training.

And in a Gemini mission in the early 1960s, they had astronauts who were in a very tiny capsule do 30 minutes of exercise every day. And they found that prevented a lot of the side effects. So ever since the 1960s, exercise has been mandatory. 

[00:07:18] Jonathan Wolf: And what is the impact for these astronauts you're describing, what happens to the astronaut who does the exercise versus the astronaut that doesn't do the exercise?

What does it mean actually for things I guess you're measuring after their 6 or 12 months? 

[00:07:32] Dr. Jessica Scott: So back in the 60s, they found that after a 14-day mission, astronauts came back and they tested the fitness of astronauts. And after just this 14-day mission, they found that astronauts had actually aged the equivalent of a decade.

[00:07:51] Jonathan Wolf: Hang on a minute. You're saying that after 14 days in space, they had got 10 years older, effectively. 

[00:07:56] Dr. Jessica Scott: They essentially got 10 years older. That's how dramatic the impact of spaceflight was. 

[00:08:01] Jonathan Wolf: I was expecting you to say six months or something. That's extraordinary. 

[00:08:06] Dr. Jessica Scott: A decade. So they found that exercise on the next mission, exercise prevented at least half of that decline in fitness.

And that's the marker that we use to look at whole body health. 

[00:08:20] Jonathan Wolf: When you're saying that it was like they were a decade older, what were you, you know, it's not wrinkles on their face that were saying they were a decade older. What were you measuring? What are you measuring to see whether this is working?

[00:08:31] Dr. Jessica Scott: So what they did back then and what we do now is essentially a stress test. So a lot of people will go to the cardiologist and they'll do an exercise test that's about 8 to 12 minutes long. It gets progressively harder and it's a maximal effort test. And at that maximal effort, that's a number we can use to estimate your age based on data that's been around since the 1920s.

[00:08:58] Jonathan Wolf: Amazing. I've heard people talk about a VO2 max test. Is that similar to what you're describing? 

[00:09:05] Dr. Jessica Scott: That's exactly the same test. And you just measure the amount of oxygen that you take in, that you consume. And that's why it's called a maximal oxygen test. 

[00:09:16] Jonathan Wolf: And so you're saying that after 14 days in space, you do that test. And so this person is say 35, go away for 14 days, they come back and suddenly it's like they've become 45. 

[00:09:25] Dr. Jessica Scott: Yeah. They're VO2 max. This is the equivalent of a 45-year-old. 

[00:09:29] Jonathan Wolf: Which is why you're saying it would be very hard to send somebody to Mars because they'd be basically like 2000 years old by the time they arrive.

[00:09:37] Dr. Jessica Scott: Yeah, it would be very similar. A mission to Mars is three years long. So you can imagine if you don't exercise. It would be very much accelerated aging. 

[00:09:47] Jonathan Wolf: And I'm guessing that there's been some work done on this since the mid-1960s, Jessica and that that's what you've been involved in. What is like the latest NASA exercise program? Like what is the learning about what to do in order to combat this? 

[00:10:01] Dr. Jessica Scott: The evolution of exercise has been really interesting in the past 20 years when the International Space Station started. So there was a lot of work that had to go into how can we get an exercise equipment into space? How can we get a treadmill, some resistive exercise devices, a cycle ergometer?

So there's a whole lot of engineering that went into those devices. And then, of course, the exercise program is how much should astronauts do. What intensity should they do it, what's the combination of aerobic and resistance exercise, and that's what everyone has been working on for the past 15 or 20 years.

[00:10:43] Jonathan Wolf: And so there's some very weird contraptions, I'm thinking that obviously, you can't run on a treadmill in space, right, like, you're just gonna shoot off stuff. somewhere. 

[00:10:50] Dr. Jessica Scott: Yeah. Actually, you can. 

[00:10:51] Jonathan Wolf: Well, how does it tell me about this? 

[00:10:53] Dr. Jessica Scott: So, very early on, they learned that astronauts who were running on the treadmill strapped down in a bungee system, because obviously they would float away if they weren't strapped down.

But they found that if astronauts were running at a certain cadence, they would float away. They would actually vibrate the treadmill and it could oscillate the entire space station. So they were worried about the space station de-orbiting. 

[00:11:15] Jonathan Wolf: Okay, because of the person running on the treadmill. 

[00:11:17] Dr. Jessica Scott: Because of the person running on the treadmill.

[00:11:18] Jonathan Wolf: That would be unfortunate, I can see. 

[00:11:19] Dr. Jessica Scott: Yeah, so they had to develop new technology to try and stop some of those vibrations that happen with the treadmill. So there's constant evolution in the technology and A lot of different aspects to think about. 

[00:11:32] Jonathan Wolf: I love this. So you're sort of strapped in with sort of elastic bands onto this treadmill so you don't go flying and then you can run as if you were in Earth's gravity.

[00:11:43] Dr. Jessica Scott: Exactly. 

[00:11:44] Jonathan Wolf: What's the combination now that you understood an astronaut needs to do? The things that need to be done in order to maintain health. 

[00:11:53] Dr. Jessica Scott: Yeah, so right now with astronauts, it's a mixture. So we talk about not doing the same exercise every single time that you do a session. You don't want it to always be a low-intensity session where you're not breathing hard or your heart rate's not increasing.

But you also don't want it to be always a high-intensity session where it's maximal effort. It feels incredibly challenging interval-type exercise. You want a mixture of both of those things to help avoid any injury and help your body adapt. 

[00:12:30] Jonathan Wolf: So one thing is the intensity. And what about the types of exercise? I'm guessing that not all exercise is not all muscles, whatever can be equal. What are the critical things that need to happen? 

[00:12:41] Dr. Jessica Scott: So it's a mixture of aerobic exercise and resistance exercise. So that's the lifting weights. And it's the mixture that helps prevent a lot of the changes in muscle size, changes in heart function.

And it's the mix that's really important. So you think of it like eating like a rainbow is what you hear, a lot of mixing it up a lot of different fruits. Then you want to do that with exercise as well. 

[00:13:08] Jonathan Wolf: Got it. And so that means when you're even when you're talking about resistance, does that mean you need to be sort of working out all the different muscles? 

[00:13:18] Dr. Jessica Scott: Yeah, for astronauts, it's a little bit different because they don't use their legs. They're not getting their 10,000 steps in. It's a lot of lower body work because when they land after being in space, they have to be able to stand up and walk around. So they really need to help maintain their leg muscle size and leg muscle function. 

So they do a lot of squats exercises, a lot of lower body. I think some astronauts really enjoy upper body as well, but it's not as critical. 

[00:13:49] Jonathan Wolf: For the rest of us who are down here on earth, does that mean that this is more balanced because actually we are using our legs and so you wouldn't be as focused just on your legs as you then apply it through to, you know, your new job, but even maybe for people thinking about health more broadly.

[00:14:05] Dr. Jessica Scott: Yeah, I think for function, the legs are the most important. So you think about standing up from a chair, you think about walking up a flight of stairs, that's mostly using your leg muscles. So those are the really important ones to focus on. 

[00:14:20] Jonathan Wolf: Also, even for those of us in gravity, like the leg is the most important thing that you would focus on.

[00:14:27] Dr. Jessica Scott: Agreed. 

[00:14:27] Jonathan Wolf: So you're not at NASA anymore. And working at NASA does sound very exciting. Why did you decide to leave NASA and turn your attention towards cancer research? 

[00:14:36] Dr. Jessica Scott: That's a question I get asked a lot because there are people ask, like, what do astronauts and cancer patients have in common? There's nothing in common.

And I was actually at a conference with a friend who was in the field of cancer, and I was describing some of the side effects that astronauts experience, but the amazing resources that NASA had put into exercise training. And she mentioned, well, that sounds a lot like what I see in patients, but exercise is not talked about at all.

And that really drove home that there's these millions of patients who have cancer, experience cancer, are undergoing treatment, but they don't have the same resources in terms of exercise, What do I do?, that NASA's had. 

So instead of devoting you know, hundreds of thousands of dollars of resources to keep seven astronauts healthy per year, a lot of those tools and techniques could be used to help thousands of patients. 

[00:15:38] Jonathan Wolf: Sounds really radical to imagine that exercise is like a tool to help the health of people living with cancer. 

I just think about my grandmother and I'm like, well, if you're sick, you should just rest. Stay in bed till you're better and then you go out.

That's definitely how I was brought up and I think a lot of people were brought up in that. So how radical is this idea that actually exercise might be helpful and I guess how new is this? 

[00:16:06] Dr. Jessica Scott: Yeah, 20 years ago I would say it was very radical. So there was the perception that if you're receiving treatment in particular, you should just rest and take it easy.

And I think that's because even 20 years ago, the survival rates were low. We were still trying to understand what types of treatment and what's the best form. 

But now we can see that a lot of the therapies have come so far, survival rates have improved so much that there's now a shift to trying to understand what are the side effects of these treatments and is there a way that we can help try and limit some of these side effects that patients experience. Because the treatments are very intense and very challenging to get through. 

[00:16:53] Jonathan Wolf: And so if you could try and help with the side effects, you might actually be able to help patients to be able to stick with the treatment and have all the benefits from it.

[00:17:00] Dr. Jessica Scott: Exactly. 

[00:17:01] Jonathan Wolf: What are the main types of cancer treatment today? And then maybe you could just talk through sort of what are these key difficult side effects that, you know, the doctors that you're working with are having to try and manage to make sure that patients can have these life-saving treatments.

[00:17:17] Dr. Jessica Scott: Yeah, so one of the mainstay treatments is chemotherapy, and that's a systemic treatment that is very good at targeting tumor cells. 

[00:17:27] Jonathan Wolf: And systemic means? 

[00:17:28] Dr. Jessica Scott: It means through your whole body. So it's something that's usually delivered intravenously. So you'll go in and it's delivered like some of it can be a pill form, but a lot of it is delivered through an IV.

[00:17:42] Jonathan Wolf: So it's effectively sort of injected into your body. 

[00:17:44] Dr. Jessica Scott: Exactly. And because it's injected it goes to the tumor cell, but it also goes everywhere else. And that's why some of the side effects start to come out as it may affect the heart, your blood vessels, your muscles, because it goes through your whole body and it's not delivered directly to the tumor.

So that's the main one that has been around since the 1950s. The other one is radiation therapy. So that's one where there's usually a targeted dose of radiation that gets delivered to the tumor. 

There are some side effects with radiation treatment as well, particularly for some tumor types like breast cancer where there could be some effects to the heart. There were some studies from just a few years ago showing that some high doses of radiation might increase the risk of cardiovascular disease. 

And then there are the newer therapies that have come out in the past five or so years. So those are like immunotherapies and that's using your own body's function to try and target the tumor cells.

[00:18:54] Jonathan Wolf: And when you talk about side effects, I think I initially thought about this idea of the immediate side effect if you're having some chemotherapy and feeling really nauseous and having no energy. And you know, I know people who've gone through that. And it's obviously really, really tough just to be able to function even more. So if you also are having to look after a family and things like that, which I've seen.

It sounds to me as though you're also talking about longer-term side effects. So could you, when you're talking about side effects, could you explain to me what they are and are they only long-term or is it short-term as well?

What are you trying to improve? 

[00:19:36] Dr. Jessica Scott: Yeah, that's a great point. So, there are the short-term side effects that happen while you're receiving the treatment. And then there are the long-term side effects, like heart disease that don't show up until seven years or ten years after you've completed the treatment.

So with the short-term side effects, and that's what happens while you're receiving the treatment, we think that exercise can be beneficial because it can help do things like improve white blood cell count, help improve red blood cell count. It can help with fatigue. 

It can help with some of the other side effects. Patients feel like they have tingling in their hands and feet. So we think that exercise can be beneficial to help prevent a lot of those side effects during treatments. 

[00:20:25] Jonathan Wolf: Actually, the fact you're talking about these risks, you know, 10 years later is is a bit remarkable because it tells you how much better the treatments are, I think.

Am I right to feel that? 

[00:20:36] Dr. Jessica Scott: 100%. And I'll use breast cancer as an example. So in the 1970s, the five-year survival rate was only 70%. So three out of 10 women didn't make it to the five-year mark. And that number is now 90%, or pretty close to 90%. That's an amazing change. It's a huge change. And that's all because of screening, newer treatments, and more precise treatments.

But some of the challenges is, we've done such an incredible job with the therapies, but now we're starting to see some of those side effects 10 years later, 7 years later, 20 years later, and for breast cancer, it's cardiovascular disease. 

[00:21:21] Jonathan Wolf: Do we understand, does science understand what's happening, like why there is that link from these treatments, which are obviously life-saving and without which you're not going to have any risk of this stuff?

So I think we're all saying that the treatments are great, but do we understand what's going on that might be causing these sort of long-term increased risks of something like heart disease? 

[00:21:43] Dr. Jessica Scott: Yeah. And it's actually very similar to astronauts again. So it's those two hits. So it's the direct hit and with patients, it's the chemotherapy or the radiation.

So as I mentioned it can target the heart so it can make the heart a little bit weaker. It can target the blood vessels and make the blood vessels not as elastic. There's probably something that's going on at the muscle as well and those don't happen right away. It takes years for some of those changes to develop.

And then the indirect hit, which is when you're receiving treatment, a lot of patients don't feel great, they don't exercise as much, they're not as active, they change their diet, they either gain weight or lose weight. So, it's a big hit to that system. 

And it's not until years later that you start to see some of the side effects like heart disease, coronary artery disease, some of the classic symptoms that happen much earlier if you've received cancer treatment than if you haven't.

[00:22:46] Jonathan Wolf: Back to your description of these astronauts that in fact this impact sort of is aging their body and so they're starting to be at risk from these diseases that all of us end up being at risk at, but sort of sooner as a consequence. 

[00:23:02] Dr. Jessica Scott: Exactly. It's almost like accelerated aging again, where you hear patients say they feel like they've aged 10 years and that's physiologically, that's probably true.

[00:23:13] Jonathan Wolf: So let's switch to the positive news then. Tell me about what your research has discovered about exercise and cancer. 

[00:23:21] Dr. Jessica Scott: Yeah. So with exercise oncology, it's a fairly new field. Again, 20 years ago, the message was just rest and take it easy. So one of the first layers of evidence that we looked at was observational.

So this is taking a large number of patients and asking them, how much exercise do you do? And what we found with that is that if patients reported doing at least two and a half hours of exercise per week, they have about a 30% reduced risk of developing cardiovascular disease. So that's a pretty big number.

And that suggests that exercise is really beneficial. 

[00:24:04] Jonathan Wolf: So just to make sure I got that right, you're saying that you did this big survey effectively, and you saw that for patients who were doing two and a half hours or more exercise a week, there was actually a 30% reduction in cardiovascular disease. So a really big reduction. 

[00:24:18] Dr. Jessica Scott: Yeah. So that's the first line of evidence showing that is really important. And we also did a study showing that it's not too late to start exercising. So typically in an observational study, you ask the exercise question at one time point. 

And in a study looking at adult survivors of childhood cancers, we asked the questionnaire at two time points. And we found that in individuals that increased their exercise even by just 30 minutes a week, they also reduced their risk of cardiovascular disease by about 20%. 

[00:24:56] Jonathan Wolf: Are there any randomized controlled trials around this? 

[00:24:59] Dr. Jessica Scott: There are plenty of randomized trials around this. 

[00:25:03] Jonathan Wolf: So tell us about it. 

[00:25:03] Dr. Jessica Scott: Yeah. So we kind of span the continuum. So we've got trials looking at if exercise is beneficial before you start treatment, exercise during treatment, and then exercise after you've finished treatment. 

And what we've shown is if you start exercising right before treatment, so we call this a window of opportunity. So you've been diagnosed and depending on the cancer type, so for example in prostate cancer, you have a four to six-week window before you go in for surgery. And in that trial we tested different doses of exercise, so what's the volume of exercise and does that improve some of the surgical outcomes?

And exercise does improve, it helps you recover from surgery a little bit quicker. 

A more recent one, we also looked at exercise during breast cancer treatment. And this was for women that were receiving chemotherapy. So again, that pretty toxic regimen that is challenging to get through. 

And with this study, we found that exercise during and right after treatment was really important in offsetting some of the cardiovascular changes that happen during treatment. 

[00:26:25] Jonathan Wolf: Now I understand from friends of mine who've been through cancer treatment that it's physically really exhausting and I think especially chemotherapy as I understand and also very mentally draining and of course they're under immense emotional strain because of this as well.

How do you make sure that this advice doesn't sort of just add another level of things that one should be trying to do in a situation where there's no capacity left? 

Because when you talk about, you know, the exercise during chemotherapy, for example, that sounds easy to prescribe, but maybe very hard to actually carry out?

[00:27:01] Dr. Jessica Scott: We recognize that there are good days and there are bad days. And so we know what our prescription is, so just like you get a prescription for blood pressure or chemotherapy, we know what the optimal dose is. 

But we know if patients are saying, oh, I'm so tired today, I just can't do it, then we capture that data. We say, no problem. Let's try a lower intensity day and we just try and work with them to figure out what's the best way that they can get an exercise session in. 

[00:27:35] Jonathan Wolf: It's amazing, Jessica. So, look, I'd love to discuss the practical advice that is coming out of your research. 

Before I do that, I think it's really important to remind listeners that this podcast is not medical advice and that for anyone living with cancer, it's really important to first talk with their oncologist about anything that they're thinking about changing with their health plan and I'm assuming, Jessica, you would be saying the same thing.

[00:27:56] Dr. Jessica Scott: 100%. That's what the first step in anything is getting clearance from your physician. 

[00:28:03] Jonathan Wolf: Now I think quite a lot of people listening to this, either who've had cancer and are living as a survivor after that, or maybe undergoing treatment, you know, around the world and the listenership to this podcast, in almost every country in the world, it’s amazing, may be thinking, you know, my oncologist didn't tell me to exercise, in fact, they told me to rest. 

Do you feel that in general, this advice of doing no exercise is still quite common? Or actually, are you seeing that there's being a sort of a big shift?

Because you're saying that 20 years ago, like, you know, nobody had this view. This is very new research. 

[00:28:42] Dr. Jessica Scott: Yeah. I think at least in the seven years that I've been in the fields, there's been a shift. So I think it's much more common to say, recommend exercise or there is less of an inclination to recommend don't do anything.

I think at least 50%. There was a recent survey that said at least 50% of oncologists recommended exercise training in the United States. 

[00:29:08] Jonathan Wolf: Okay. So that's a pretty big shift. 

[00:29:10] Dr. Jessica Scott: It's a big shift. 

[00:29:11] Jonathan Wolf: But not yet. It sounds like you are hoping that it's going to end up at a higher number than 50%.

[00:29:16] Dr. Jessica Scott: Yeah, exactly. And again, it's very different in countries around the world. So in Denmark and Norway, it's standard that if you receive a diagnosis, you can get an exercise program or go to an exercise center. 

[00:29:30] Jonathan Wolf: Is that right? So there it's completely the norm. So you really see a difference from country to country today.

[00:29:36] Dr. Jessica Scott: It's completely different. And that's where we're trying to get in the United States is that similar. And we just need the evidence showing that exercise is beneficial. 

[00:29:47] Jonathan Wolf: I think the natural next thing I want to ask is you've used the word exercise a lot and I'd like to understand what that means. Because I feel that whenever I speak to scientists, like what they mean by exercise can mean something very different from what most people listening to this is, which is going to the gym or going for a run. Is that what you mean?

[00:30:10] Dr. Jessica Scott: And a lot of our programs are walking because it targets so many systems. Walking is great for your bones, for your muscle, for your heart. So it's a great way to target as many systems as you can at one time, a bigger bang for your buck.

But there are certain patients who have low muscle. So there's certain types of chemotherapy or certain history where you're starting out with not as much muscle mass as you might need. And that's where it's important to try and incorporate some of that resistance training. 

A lot of the work can be done, depending on the level that you start with, is with bodyweight exercise. So a lot of it is doing standing up and sitting down in a chair, that is a squat. 

And then as you get a little bit stronger, you can add some resistance bands. So these are the stretchy bands that add a little bit of resistance. And the goal is to gradually build up your muscle size and your muscle strength.

[00:31:13] Jonathan Wolf: So that all sounds a lot less scary in a way than the resistance training. So I feel there's some branding to be done here, Jessica. 

[00:31:19] Dr. Jessica Scott: That's probably true, yeah.

[00:31:22] Jonathan Wolf: So that's really interesting. You're saying even that this really makes a difference to these side effects. 

[00:31:30] Dr. Jessica Scott: 100%. It's all about starting slow and continuing on and building.

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[00:31:36] Jonathan Wolf: So imagine that we have two people. One is maybe,  you know, a 60-year-old woman with breast cancer and another is maybe a 25-year-old man with testicular cancer. And they both have an average level of fitness for, you know, their age. 

Just to make that practical understanding, how might their recommended exercise program differ if at all?

[00:32:07] Dr. Jessica Scott: Yeah, I think the overall program would not differ that much between the two. I think their prescribed doses of exercise may differ. So the 60-year-old woman with breast cancer may start at a lower level of exercise. For example, she may start with just doing a 20-minute bout of walking exercise and then start with 60 minutes a week of exercise and gradually try to build up from there.

Whereas the younger testicular cancer individual, he may want to start a little bit longer. So he may have a little bit higher capacity and he may be interested in doing resistance training at the same time. 

So again, it's trying to tailor the exercise program to the different levels and the different interests.

[00:33:00] Jonathan Wolf: And this is about being realistic about where you are, rather than like having some, you know, which I think is often what scares people about exercise, right? It's this theoretical idea of this amazing activity you can do, whereas you're just saying stop where you are and then you can move a little bit and it makes a big difference.

[00:33:16] Dr. Jessica Scott: Exactly. That's the key is look at your levels, where you're at, what are you doing previously and start there and try and build up. 

[00:33:25] Jonathan Wolf: Now, I'd love to pull it back to the things that you were describing with NASA at the beginning, which I know is important also in your research. Which is I think you call it nonlinear exercise, which as I understand it's like, it's a var from what you're saying, it's like a varied exercise program.

Is that also important here, and what would that mean for… could you maybe help me to visualize what a program might look like across a week as a result? 

[00:33:50] Dr. Jessica Scott: Yeah, it's great. So we actually train all of our patients exactly how astronauts train. 

[00:33:57] Jonathan Wolf: So they get the NASA astronaut training. 

[00:33:58] Dr. Jessica Scott: They get the NASA astronaut program.

[00:33:59] Jonathan Wolf: That is good branding. 

[00:33:02] Dr. Jessica Scott: The difference is it's individualized. So, people may get scared when they think, oh my gosh, I'm training like an astronaut. But that's not how the exercise program works. 

So, your maximal heart rate, for example, may be 150, whereas my mom's maximal heart rate is 120. So you're not going to be going at that same level. But we will incorporate some harder, high-intensity exercise for all patients and some lower-intensity. 

And we typically use five different training zones. So the five is the very high-intensity interval exercise where you're breathing your hardest, you're almost at maximal effort, but those are intervals. So, it's doing two minutes on and two minutes off. 

Zone four is a little bit less intense, but you're still breathing quite hard. And you contrast that with zone one, which is a little bit longer, but it's very easy. You can carry on a conversation. It feels like you could go forever, and it's a mix. 

We want to incorporate a mix of all of those different intensities, and that's what we do with patients, and that's what astronauts do as well.

[00:35:19] Jonathan Wolf: And are there different sorts of exercises that you're doing as well? So is the variety only the intensity, or is it also like actually doing different types of exercises? 

[00:35:30] Dr. Jessica Scott: So the variety is in the length of the session. So they can range anywhere from 20 minutes up to 75 minutes in some cases, and that varies with the intensity.

[00:35:45] Jonathan Wolf: So the variety for me is not that I'm necessarily having to think of seven different types of exercises. The fact that today I might do 40 minutes and tomorrow I might do 20 and the day after you're 75 or whatever, and that this is somehow affecting my body. 

It's not just because I might think, well, it's just obvious the 75 is better than the 20, but you're saying actually the variety itself is valuable.

[00:36:08] Dr. Jessica Scott: Exactly. The variety is key. 

[00:36:10] Jonathan Wolf: Help me to understand why. Because I think again, I'm like, well, it's obvious, isn't it? Like just doing more must be better. 

[00:36:15] Dr. Jessica Scott: Yeah. I think that's again, a very common conception is, you know, I need to go hard all the time to get them. And we found that that's not the case. So it's the going hard one day, but then going easy the next day.

And there's a couple of different reasons for that. The hard, high-intensity days, they're really good at targeting the muscles in your legs. It helps oxygen extract a little bit better at your muscle level. 

But the lower intensity and longer days, the ones that feel really easy, are really important to target your heart. It allows your heart to get a little bit more flexible and a more flexible heart is healthier. 

So it's the mixture of all of those intensities and durations that really help your overall health. 

[00:37:06] Jonathan Wolf: And I think there'll be some people listening to this who are going to say, well, that sounds good, but surely it can't really be safe for someone to do something really high intensity where you're saying that they're like, push their heart as hard as possible.

You know, surely that can't be safe. 

[00:37:22] Dr. Jessica Scott: It is safe after you've received clearance from your primary care physician or your oncologist. 

So we typically do an exercise test before starting an exercise program so we can make sure that we know what your maximal heart rate is, what your capacity is to do the maximal type of exercise.

And that's really key is to get the clearance to make sure that you can do that different high-intensity exercise. But even high-intensity exercise doesn't need to be maximal exercise. Even just finding a hill and walking up a hill one day and then picking a flat walk another day, that's alternating your intensities as well.

[00:38:10] Jonathan Wolf: Now, you mentioned sort of early on that I'd like to come back to in your research, thinking about timing. Should your exercise program start the second that you get this diagnosis? Should it be changing, you know, after treatment versus during treatment? How do you think about that?

[00:38:31] Dr. Jessica Scott: That's a really interesting question as well because patients are receiving this very tough treatment, should they wait and then start exercise after they've gone through a couple of cycles or should they exercise during and after? And we just finished a trial looking at that exact question.

And what we found was that for women receiving chemotherapy for breast cancer, exercising during and after chemotherapy, so a total of about 32 weeks. That was associated with the greatest improvements in overall health, both in terms of how patients reported feeling. 

So less fatigue, less side effects for themselves. And then what we measured physiologically it was better to exercise during and after. So basically start as soon as you can, and then keep going. 

[00:39:27] Jonathan Wolf: So in many ways, I feel like this advice is quite similar to when you just talk about exercise in terms of health for somebody who's not, you know, living with cancer or some other disease. Which is the best time to start is today, and the best time to stop is never.

And is that's what you're actually seeing even when you're dealing with these horrible treatments or recovery. Is it in a sense as simple as that, Jessica? 

[00:39:55] Dr. Jessica Scott: Yeah, that's what we've seen is, you know, it's never too late to start. It's just, you know, try and get out for a five-minute walk.

It's that movement that is really beneficial. 

[00:40:07] Jonathan Wolf: I think that is fascinating because we've discussed on other shows this idea that I've certainly been brought up to believe that, you know, when your parents get to a certain age, then suddenly you should take their bags away from them and make them rest, and do anything very good.

And I've been told by various scientists, Oh, well, actually the best thing you could do is probably give them your bag to carry up the stairs if you really want them to live to 90. 

Now, I understand that here you're not as extreme as that and it needs to be within the constraint of what you're able to do.

But fundamentally, you're saying even in this really quite extreme situation, actually, if there is the capacity to do some more, and when you say exercise this again, this is sort of walking around, amazingly, actually, that can be helping you. It is remarkable and shows, I guess, like this big swing away from I think a lot of the advice that we live through in the 20th century.

[00:41:02] Dr. Jessica Scott: Exactly. 

[00:41:03] Jonathan Wolf: And Jessica, what are the next steps for your research? 

[00:41:07] Dr. Jessica Scott: Yeah, our next steps are, we're again trying to push the boundaries a little bit on exercise training. 

The majority of work so far has been very conservative in how much exercise patients can do. And I think that's been right. For the past 15 years is, you know, is it safe? Can patients do it? 

So now we're testing bigger doses, so there's a couple of trials where we're looking at 450 minutes of exercise a week and trying to figure out what is the best dose of exercise for each individual patient. 

[00:41:41] Jonathan Wolf: And that's well outside the doses that you've been doing up until now.

[00:41:44] Dr. Jessica Scott: It's well beyond. So all of our trials previously of the most has been 150 minutes. 

[00:41:50] Jonathan Wolf: Okay, so there's dramatically more exercise and I get the sense looking at you smiling here, which you won't see if you're just listening to podcasts, is you're quite optimistic that actually there's continued benefit, you know, if you go to significantly more exercise. And obviously that's not proven at this point. But am I right that that is the hypothesis? 

[00:42:09] Dr. Jessica Scott: I think I think we'll find a dose that maybe you don't need to go that high, but I think we need to test the higher doses to say 450 minutes. Patients could do it, but it was had the same benefits as 300 minutes. So I think overall, in general, 300 minutes will be fine.

So we're testing those in different ways and seeing what's the most dose that patients can do feasibly. Because obviously there's life, there's work, there's kids, and it may not be feasible. And that's what we're testing. 

[00:42:45] Jonathan Wolf: Amazing. Jessica, thank you so much. I would just like to try and summarize this and please correct me where I've got any of this wrong.

We started actually out in space, which doesn't normally happen on this podcast, talking about the fact that actually being in space is incredibly unhealthy. And you said that NASA discovered a long time ago that after only 14 days in space, these astronauts would come back and their bodies were a decade older than when they went out, which is pretty terrifying. 

And then they discovered that if you could get them to do this exercise in space, you could sort of halve that damage. 

And that you've been part of this program to understand more and more how to make that exercise optimal. And a big part of the discovery was you need to have both this sort of cardio exercise where you're getting your heart rate up, you know, as we often think about walking or running, but also resistance training where you're having your muscles working against it.

And that the leg exercise is the most important thing. So although your arms might matter, actually, that the leg was the most important.

Now you might think, well, Hey, that's relevant for seven astronauts you said. But amazingly, it turns out that this is really relevant for people down on earth and actually people going through both cancer treatment and living afterwards.

And that this is very new. And one reason why it's really new is actually just that survival rates have got so much better. Which is wonderful. And so suddenly people are starting to worry about sort of the long-term impact of treatment. Whereas before, you know, it wasn't really going to be very relevant what the 10-year risk was if the treatment was not so good.

And I think you shared, for example, this amazing improvement in breast cancer survival rates at five years. 

And you then explained that there's a number of different treatments. I think you said chemotherapy, radiation therapy, immunotherapy, they have different impacts. But all of these are actually having both side effects while you're going through the treatment, but they're also having an impact on your body that can affect your health later.

And so, that doesn't sound good, but then there's this really great news that actually it turns out that exercise can actually help with this. And so you said there were real studies about this where I think you said two and a half hours a week of exercise could actually reduce your risk of heart disease by 30%?

[00:45:11] Dr. Jessica Scott: That’s right.  

[00:45:12] Jonathan Wolf: Which is a big deal.

And then you've been doing all these fascinating studies to say, okay, how can you make that happen for real? And that when we talk about exercise, this is not like going into the gym and bench pressing your own body weight. Actually, it's a lot about walking. 

And you were saying that even just starting with 20 minutes of walking for a lot of these patients really makes a difference. It's affecting their bones and their heart and their muscles. 

And critically, one of the other things that you've learned from all this NASA exercises is actually you want to vary this. 

So it's not like you're saying the same amount every day, actually you're describing this thing where you go from 20 minutes to 75 minutes. And I was thinking, well, 75 minutes must be best. But actually saying the variation of this is, is really important and is having an impact. 

And I think the other thing we talked a lot about is like. It is tough going through this. Patients need to know that it's okay to have bad days. You have some good days and some bad days.

Rest is also important. And that if you can't do any of this, that's also okay. There's a lot of other pressure, but that actually, I think the data that you're sharing is that for a lot of people, it's sort of the opposite of what we might expect, that this exercise is actually helping them to get through the symptoms of their treatment.

So it's not just about reducing this long-term issue. It's a lot about making your ability to deal with the short-term impact of this treatment and therefore, therefore get through it. 

And then I think finally you said you've got this whole new study where you're actually going to be increasing further the dosage of exercise and are quite excited that potentially even higher levels of this exercise might have even more positive impact.

So I think we definitely want to get you back to hear about that. Did I manage to capture this okay? 

[00:46:53] Dr. Jessica Scott: It was brilliant. It was a brilliant summary. 

[00:46:56] Jonathan Wolf: Thank you so much for taking the time and taking us through this really amazing new science. 

[00:46:59] Dr. Jessica Scott: Wonderful. Thank you so much. 

[00:47:01] Jonathan Wolf: It's a pleasure. 

I hope you learned something today and enjoyed the episode.

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