#099 The Science of Exercise for Cancer | Kerry Courneya, PhD

Exercise as cancer therapy: Kerry Courneya on how training recalibrates tumor biology

Courneya's 600+ studies show exercise enhances immune function, improves treatment tolerance, and influences cancer progression.

"Yeah, I would imagine also if there would be some evidence looking at resistance training added on to that, it would be beneficial because, you know, post-surgery in particular, you're less mobile after, right? And, you know, so you end up losing muscle mass and it's really hard to gain that muscle mass back after, at least when you're older, after an event like that. Yeah, the muscle mass in cancer is critical. Cancer can become a wasting disease, this phenomenon called cachexia, where you get muscle wasting, especially once you get advanced or metastatic cancer. but now there's a lot of research showing that low muscle mass is really the critical thing driving risk of recurrence and deathatic cancer. But now there's a lot of research showing that low muscle mass is really the critical thing driving risk of recurrence and death from cancer. So these patients who have low muscle mass or lose muscle mass when they're going through these difficult treatments tend to have the worst outcomes. So it's prompted a lot of research now into the resistance training angle versus the aerobic exercise angle. Wow. Does resistance training counter cancer cacaxia? Because I know that's a little bit of a different mechanism. Is that an inflammatory-driven mechanism that's breaking down muscle? Yeah, I don't think they know all the mechanisms right now of why that's going on. But they've attempted to address it mostly with nutritional interventions and supplement types of interventions, but not had great success. There is some research looking at exercise and strength training seems to have modest benefits. But I think ideally, we'd want to intervene earlier and prevent patients getting from that cachexic state because then things progress very rapidly once you get into that cachexic and it's very hard to reverse it at that stage. But if we can prevent it up front and delay it, I think that would be a really important benefit. Yeah, that's a really good point. I mean, on the prevention stage, it would be you have to be incorporating regular resistance training, strength training into your workout routine because you want to have, you want to basically build up that muscle reserve that you have more to pull from if a terrible thing like a cancer diagnosis occurs and cancer cachexia, I don't know exactly what drives it all, but if it, you know, kicks in, at least you have more muscle to start with, right? Like that would be. And there is. And of course, that feeds into the whole obesity paradox, right? Which is obesity is a risk factor for getting a chronic disease, but it actually helps you live longer after a chronic disease. So we've seen that in a few of the studies, say with lung cancer, that once you're diagnosed with lung cancer, patients who are actually larger, more obese, have a little bit longer survival. And I think it gets into this idea of the reserves that you've built up and sort of this rapid decline that's going to occur. I think the obesity angle may be important, but it's probably even more important with the muscle mass, right? The larger amount of muscle mass is going to help you live longer, you know, as cancer sort of takes this toll over the course of months or years. Do people with obesity also have more muscle mass? Are they just eating more calories, including from protein, which is a signal for muscle protein synthesis? Yeah. And the research shows there's no necessary link between that. There is this phenomenon we call sarcopenic obesity. So there's high rates of obesity, but those people have fairly low lean body mass as well. So there's different kind of phenotypes, if you will, of the obesity. And you're right, the real issue we want to look at in obesity is how much muscle mass versus how much fat mass. And look at kind of that fat to lean ratio. And that's really the more important factor. Some people who have very high weight might have a lot of muscle mass and be in very good shape. Others might have a balanced muscle mass, and then others might have very small muscle mass despite these high levels of obesity. You know, the other thing I wonder, Kerry, is oftentimes you'll see in some of the scientific literature obesity defined as a BMI of X, fill in the blank, right? And if they're measuring BMI, you know, some people that are lifting weights that are very muscular have a high BMI. And if you were just to look at BMI only and not like hip to waist ratio and other factors, you might actually miscategorize someone as obese. And so I wonder, it'd be interesting to see if there's anyone that's looked at this obesity paradox and whether or not that's contributing to confounding that data. Yeah. And that's definitely one of the explanations for the obesity paradox. And that is it's not a good quality measure of body composition. So in our research and other research, we'll either look at DEXA scans that allow you to look at fat mass and lean mass. But what they've done in the cancer field is all these patients are getting scans to track the tumors. And these scans will go through the skeletal muscle in different places. And they're able to get really good quality measures of how much skeletal muscle mass you have. And they're the ones who have pointed out that's really what's driving these survival rates is this low muscle mass, which also drives low physical functioning and poor quality of life as well. So I think, you know, in the cancer field, muscle mass and strength training are turning out to be critically important. Yeah, that's really not something that at least, you know, in the past decade or so or more was really talked about, at least within the context of why it's important to be fit with a cancer diagnosis, right? Usually you think about aerobic exercise and the stress of aerobic exercise. And of course, there's all these mechanisms that occur. But it is really interesting to think about how important having that muscle reserve is if you are going to get diagnosed."

Aerobic exercise, resistance training, and HIIT all show cancer-fighting benefits

Structured exercise programs combining aerobic, resistance, and high-intensity intervals can mitigate treatment side effects and enhance immune.

"Is there any type of tracking that can be done for tracking these types? I mean, can you get a blood test and measure circulating tumor cells? Is that something that a test is sensitive enough to do? So that's the new area of HOT research. So in the past, we could essentially only detect these cancers based on imaging. So these metastases would have to grow to a certain size, like one millimeter, two millimeters, before they would show up on these scans. So small numbers of cancer cells we couldn't detect. And so you're waiting many, many years, you know, doing a follow-up scan five years later, and all of a sudden you see a spot on the lungs or a spot on the liver and say, okay, that could be cancer. So this whole idea of can we find them earlier through blood tests, what they're calling liquid biopsies. And this is an area of a lot of research now where they're trying to develop these blood tests to detect small numbers of circulating tumor cells or small numbers of circulating tumor DNA, because these cancer cells will grow, divide, undergo cell death as well, and they'll shed some elements into the system. But this is very experimental. It's not being used in clinical practice right now, but there's a ton of research on these blood tests and liquid biopsies. So that would revolutionize cancer care if we can actually go in at the time, do a surgery, remove the tumor, and then test a few weeks later to say, are there any elements of circulating tumor cells still around, giving us an indication of, okay, well, maybe we need further treatments with chemotherapy or immunotherapy. So it would revolutionize the field, but it's not in clinical practice yet. Well, there are consumer available tests like GRAIL that are available, these liquid biopsy tests that are done. Do you think, what are your thoughts on like someone that's healthy without like a family history or perhaps with a family history of cancer doing a liquid biopsy like the GRAIL test versus maybe like the situation that you're saying, which maybe it may be a little more applicable, where someone has had a cancer diagnosis, has successfully, quote unquote, successfully undergone treatment in that the primary tumor seems to have gone, by all means. And they go and do a grail test and perhaps maybe find something or don't find something or maybe monitor. Maybe someone does it yearly, annually. I don't know. What are your thoughts on those tests? It's probably too early for the science, so you're talking about using it on sort of the prevention side of things or the early detection side of things as opposed to the treatment recurrence side of things. Just reading a study today in colon cancer, they've got a blood test now out for colon cancer. They're comparing it to colonoscopy because that's the gold standard way we detect. And it is fairly effective. It was like 80% sensitivity and 90% specificity, but they still were not recommending that for the general population. But I think it's coming down the pipeline. I mean, if it is available privately and you want to get that test done, you know, you want to check with your doctor in terms of how to interpret it and make sure you're looking at things properly. But I think that technology is coming down the road and it may not be too many more years when the average person is getting a blood press on, on the early detection side of things. Um, on the, on the cancer recurrence side of it, let's say someone wants to pay out of pocket and they're going to go do, I say grail cause that's like the biggest, probably most studied one that's out there for consumers. and let's say they find, oh, I have a positive test. I've got some tumor cell DNA that was detected, and it's the same kind of cancer that I was previously diagnosed with. What would be the next steps for someone? Do they go to the oncologist and then somehow verify? I mean, is there any way to verify if that's, you know, if the test, you know, is accurate or? So on the post-diagnosis, the recurrent side of things, it is being used in clinical practice to some extent. So their oncologist may already be recommending that. So I would check with your oncologist to see if that is something that's recommended. The whole advantage, the idea of this is we have to be careful that we're not over-treating cancer, and of course, we're not under-treating cancer. So right now, we over-treat a lot of patients because we're not sure if they have any remaining disease, but we just want to be sure, and so they get all these treatments that they ultimately didn't end up needing. So one of the advantages of this testing on the post-treatment side of things is if there is no evidence of any circulating tumor cells circulating tumor DNA, we can potentially de-escalate the treatments and say, you don't need any further treatments right now. For the patient that test is positive, we probably do want additional treatments if there's evidence that there's still a small number of cancer cells around. So usually we'll recommend additional chemotherapy or immunotherapy depending on what the doctors find. So yeah, check with your oncologist if that's already built into the clinical care or whether that's something that would be recommended. Well, back to this exercise as insurance and the fact that, you know, aerobic exercise in particular, anything that's really increasing blood flow does seem to really have an effect on these circulating tumor cells. Then it would seem silly for someone who is, has been diagnosed, has been treated for cancer to not be just moving like their life depended on it, right? Exercising as much as possible because it seems like that would be your best bet for reducing the cancer metastasis and ensuring that these circulating tumor cells do not go and take camp into another organ. Yeah. Yeah. So again, we have a lot of research suggesting that. It's still experimental, but I still think it is one of the few things that patients can do themselves, right? Everything else is done to them, done for them in terms of the chemotherapy, the surgery, and so on. So patients are looking for what sorts of things can I do myself? And exercise probably has the strongest evidence of additional potential benefit beyond sort of their current treatments. So yeah, I think in some of these cancers, we are going to be able to show that there's absolutely benefits to improved outcomes for these patients. Are there, so you've done a lot of research on a variety of different types of cancer in conjunction with exercise and, you know, standard of care treatment, prostate, breast, colorectal, on and on. So have you noticed that the different types of exercise affect these different types of cancers differently in terms of combined treatment? Yeah, there are some differences among the cancers. So even though we use the term cancer like it's a singular disease, you know, it's a collection of over 100 different diseases. And all the mutations that drive these cancers can be different. So not everything is going to be sensitive or receptive to an exercise intervention. But we see this with all treatments, right? Some cancers are chemo-sensitive, some are chemo-resistant, some are radio-sensitive, some are radio-resistant. We've even seen in immunotherapy that we make incredible gains with certain types of cancers. But in other cancers, immunotherapy doesn't seem to be effective at all. So we need to think this way about exercise. You know, exercise is not going to be a magic bullet for all these cancers. So it seems to help with certain cancers more so than others. And, you know, when you think on the prevention side of things, their strongest association seems to be with colon cancer. So those cells might be particularly sensitive. Breast cancer has a strong association, where some other cancers, we don't see much of an association like rectal cancer, prostate cancer, and stuff as well. So the different types of cancer, we might find cancers that are exercise resistant and cancers that are exercise sensitive, depending on the types of mutations that are driving those cancers. But in addition to the types of cancers affecting the type and benefits of exercise, it's also really the treatments. What treatments the patient's on might determine what type of exercise is best, what amount of exercise is best. And to give you one example, we've really found a really good fit between weight training and a treatment for prostate cancer called androgen deprivation therapy. So men get diagnosed with prostate cancer. One of the main treatments is to eliminate their testosterone because testosterone fuels the growth of prostate cancer. So they're given these drugs which take them down to castrate levels of testosterone. That's fantastic for the prostate cancer, but it's not very good for the man in terms of health, strength, muscle weakness, and these types of things. So these guys who are on these androgen deprivation therapies, we've done multiple studies with weight training. And that seems to be a really effective intervention for these guys to regain their strength, regain their muscle, and improvements in things like fatigue and energy. So again, depending on the types of treatments, certain types and amounts of exercise may be more beneficial. I wonder if it's interesting because compound lifts and lifting heavy is probably one of the strongest lifestyle factors that can increase testosterone, actually. I'm wondering if it's having more of a local effect on muscle and not, you know, going to the prostate versus, you know, I guess other things that would increase testosterone. Yeah. So that was one of the concerns of the clinicians when we first approached them about the patients. Oh, maybe exercise is going to increase the testosterone and help this prostate cancer grow. So a couple of things. One, these drugs are so powerful. They take testosterone down to castrate levels. The small impact of exercise, the doctors are not worried that it's going to override that. But also those effects you're talking about tend to be just acute effects. The chronic effect can be a little bit of a reduction in testosterone. But it is one of the explanations for why exercise might increase, say, prostate cancer risk. Some of the studies are mixed on that. Well, if it's driving testosterone levels. But in the context of cancer treatment, it would be very, very small compared to what these powerful drugs do. Well, I'd love to kind of, on the flip side of that, talk about exercise as a monotherapy. So there's been some pretty recent large-scale trials that you're involved in, ERASE, the PREVENT trial, that are potentially going to be looking at exercise as a monotherapy in low-grade, early-stage cancer. This is an area that really excites me, so I'd love to hear a little bit more about that. So as I mentioned, you know, most cancers get treated with a combination of treatments that we give in different combinations, in different sequences. So these patients are very heavily treated. When we think about exercise as a monotherapy, we think about exercise by itself. What's the effects of exercise by itself on cancer? So we've done the preclinical studies in mice. We can take these mice, we can inject small number of cancer cells or implant small cancer tumors, and we can randomly assign them to exercise versus no exercise, just like the drug researchers would do, drug versus not. And we can show in those studies that exercise by itself, independent of any other treatments, tends to slow the growth and spread of these cancers. Most of the studies are showing that. Not all, but most of the studies. So then you think of clinical scenarios. Well, if all these patients are getting treated, what's the relevance of that clinical scenario? But there's a new clinical scenario in cancer. And as I mentioned before, there's concern that some of these small, low-grade cancers, maybe we're over-treating them. Maybe we're jumping in and treating these patients, causing all sorts of side effects, not to mention the medical costs and so on. Maybe they don't need to be treated. And this whole approach to managing cancer is now called active surveillance. So these cancers are so small and so low-grade, slow-growing that we're not going to jump in and treat these cancers with anything. It's being used mostly right now in prostate cancer. That's where they've pioneered this active surveillance. But it's starting to get attention even in other cancers about maybe some of these cancers we don't need to jump in and treat right away. So now you've got these guys diagnosed with prostate cancer, and they're not giving any treatments whatsoever. So this has allowed lifestyle researchers to kind of jump in and say, what's the role of lifestyle here? Can we help these guys out at all? So we've done a recent study looking at high-intensity interval training in these men with prostate cancer who are on active surveillance, no other treatments. In addition to improvements in fitness and function and the types of things you might expect, we also showed that this high-intensity exercise lowered prostate-specific antigen levels, PSA levels. So this is how men are sometimes screened for prostate cancer. Looking at PSA levels can be an indication of how much cancer there is in the prostate. So we showed that this high-intensity exercise lowered PSA levels. And then we also looked at these prostate cancer cells in a Petri dish, just an in vitro model, where we exposed those prostate cancer cells to the serum of the men who exercised or the serum of the men who didn't exercise. And we showed that exposing them to the serum in the men who exercised reduced the growth of those prostate cancer cells, suggesting that there's something that exercise is doing, and we think it's the anti-inflammatory, the insulin IGF, immune system effects that are slowing the growth of these prostate cancer cells. So this is a very exciting area because many of these guys who are on active surveillance ultimately will require treatments. So if you can delay the need for treatments or prevent treatments, you can substantially improve their quality of life. So a very promising exercise intervention in that clinical setting. Why did you choose high-intensity interval training as your exercise intervention type versus something perhaps more moderate intensity like jogging? Is there something about HIIT and vigorous exercise that you felt was maybe more beneficial for the prostate cancer, or is it just easier to adopt that type of routine for people? I think it's the evidence suggesting that high-intensity activate activates more of these biological changes. So I think of it kind of as stirring the biological soup, right? The body's got all these biological processes. And the more intense the exercise, more of these biological changes get stirred up. So you're going to send more immune cells into the peripheral blood, more of the changes in insulin and IGF, more of the anti-inflammatory markers. So there seems to be a dose intensity effect on some of these biological changes. And because we're targeting biological changes as opposed to functional changes, we want to go with what we think is the optimal exercise prescription for really driving biological changes that might be relevant for cancer growth. So how do you guys, and maybe in this trial or in generally speaking, take someone who's under active surveillance, maybe they have been sedentary, they're not someone that's really done structured exercise, you know, as a routine, and help transform their fear because I'm sure it's scary to be diagnosed with prostate cancer as early or as, you know, I would say, you know, low grade as it is, it's still probably a very scary, fearful process. Are there any sorts of programs, structured programs that can help, like having a coach or group classes, things like that, that what would help for someone in that situation? What did you guys use in the study? Yeah, so many of these guys are quite motivated to do something for themselves. So that's one of the big motivating factors, right? Waiting around just for treatments or just getting the surveillance, which is, you know, regular PSA screenings and biopsies and those types of things. So many of these patients, cancer diagnosis can be a bit of a wake-up call. It can be a bit of a teachable moment in the sense that, oh, you know, I am not immortal. Maybe I do need to take care of my health. So oftentimes it prompts patients to say, what can I be doing to try to improve my health? So some of it is just the experience of a chronic disease. It can be very scary and thinking about taking your health more seriously than you might have done when you're focused on the prevention side of things. So we motivate those guys by talking about the cancer-specific benefits. As I say, if it's just improvements in fitness, just improvements in strength, yeah, these are the standard benefits that everybody gets, but what about me? And cancer patients are very concerned about their cancer. Once you're diagnosed with breast cancer or liver cancer or brain cancer, you become focused on what kind of diet should I eat for someone with brain cancer? What kind exercise should I do with brain? You're not interested in general health benefits. So they want to know about these cancer specific benefits. And so we'll usually talk about those types of benefits to try and motivate them, say, hey, this might actually help with your cancer. It might help with your treatments, getting through the treatments, recovering from treatments. And of course, we always work with them where they're at. We tell them, you know, we'll never ask you to do more exercise than you can do. We'll progress you slowly. We'll build you up to the prescription. One of the other key things for cancer patients is the opinion of the oncologist. The oncologist is absolutely crucial. You know, if the oncologist says that that patient should be exercising or think about exercising, they take that very seriously. So we've been able to get the oncologist on board or the urologist and say, hey, your urologist thinks, you know, with your prostate cancer that you should be exercising as well. So it's really building that team of support and motivating patients with the benefits that are going to be specific to them and their unique situation. With the oncologist and getting them on board, is that something, you know, you often do still hear, again, even oncologists will say to take it easy to rest, especially if they're going to undergo, you know, they're not in active surveillance, but perhaps they're going to undergo a treatment like a chemotherapy treatment or radiation. And so how do you sort of change the paradigm here and help perhaps a patient give the right information to their oncologist, like giving them studies? Or what can help sort of change the oncologist from a you should rest and take it easy or just a light walk around the neighborhood to, okay, we should do some high intensity interval training classes to help with treatment? So the short, simple answer is evidence. So oncologists will recommend for patients things that are evidence-based. And one, I think, the real strength of the exercise oncology field is we've subjected exercise to the same rigorous research that they would subject their drugs to. So we do randomized controlled trials, which are sort of the gold standard research methodology with large sample sizes showing these benefits for their patients. And then we publish them in the top cancer journals that the oncologists read. So that's what they're looking for is evidence, not that anecdotal stories about, hey, my Uncle Fred did this and his cancer went away. They want to see these high-quality research studies. And so that's been building over the last couple of decades, slowly at first, but now much more quickly, where the evidence is getting out there. And most oncologists are now aware of it. In fact, two years ago, so only in 2022, two years ago, the American Society of Clinical Oncology put out its first exercise guidelines. So this is cancer doctors. So it's one thing for exercise specialists to say, hey, cancer patients should exercise. But now we have the cancer doctors themselves, their professional organization, ASCO, the American Society of Clinical Oncology, says all cancer patients who are being treated with curative intent should be recommended aerobic and resistance exercise while they go through treatments. And those guidelines are adhered to very closely by oncologists. So they almost all of now will be aware of these new ASCO guidelines saying, you need to be recommending and referring your patients to a good quality exercise program to help them get through treatments. Well, that's really good news to hear. I want to kind of circle back to something you mentioned earlier with respect to the benefits of exercise along with treatment in cancer patients on psychological health. And maybe you can talk a little bit about how important these benefits are compared to maybe some of the anti-cancer benefits. Or perhaps even, you know, you have one of the big takeaways from the ERASE trial was that exercise seemed to reduce the fear of progression. and along with fear and the stress, you get stress hormones, and stress hormones really can help fuel tumor growth as well. So maybe you can sort of talk about the psychological benefits and sort of are they uncoupled from the anti-cancer benefits. Yeah. So in one way, it's one of the surprising, I think, findings in this literature. When we talk to some of our patients, they will tell us that the psychological benefits are more important to them than even what it's doing to the cancer or some of these other outcomes, because it can be very difficult to cope with cancer psychologically. As I mentioned, cancer patients will say everything about cancer is not normal. And when they exercise, they start to feel like they have some control over the cancer and that their normal life. I'm out playing tennis or I'm out golfing. I feel like I'm normal again. So these psychological benefits can be things like improve self-confidence, improve self-esteem, certainly managing the anxiety associated with cancer. And you mentioned the finding related to fear of cancer progression or fear of cancer recurrence. This is a huge issue in cancer patients. You can imagine being diagnosed with cancer. You go through the different treatments. At the end of the treatments, we tell the patient, there's no evidence of disease. We've done the scans. We've done the various other tests. We think it's gone. How will we know it's gone? Well, we're going to follow up every six months, and we're going to do these tests, and then we're going to tell you whether the cancer's come back. So we can't tell you definitively at the end of treatment that your cancer's gone, go back to your normal life. We know these recurrences happen. And now you can imagine every six months, the anxiety and stress of going in and getting these imaging tests and blood tests, and then meeting with your oncologist is going to say, the cancer's back or it's not. And patients will tell you that finding out they've had a recurrence of the cancer is even more devastating than the initial diagnosis of the cancer. So this fear of cancer recurrence can paralyze these patients as they continually go through this surveillance. And at no point can we ever tell them that the cancer is definitively gone. In some cancers, there's recurrences 10, 15, 20 years later. So this is very stressful. So the impact we showed in this study of exercise, helping them manage that fear of cancer progression or fear of cancer recurrence, really important, helping them get on with their daily lives to say, I have to live my life with cancer in the background, even though, you know, I have this psychological stress. So yeah, those psychological benefits, I think are really important for these patients, in addition to some of the functional benefits and the disease-related benefits and controlling the side effects. There's been some pretty large randomized controlled trials over the years, and even meta-analyses of these randomized controlled trials, comparing exercise, whether it is aerobic, a lot of times running or cycling, even resistance training has been thrown into the mix, comparing them to standard of care treatments for major depressive disorder, like SSRIs, right? And exercise as a treatment, it seems to work just as good, if not better, than a lot of these SSRI drugs are working for the treatment of depression, which is amazing because then you're going to get all the cardiovascular benefits, the muscular benefits, metabolic benefits, right? Like the endless benefits of exercise in addition to the mood benefits, right? So it's not that surprising to me that exercise would have a very positive effect on, you know, on mental health of cancer patients, on reducing anxiety and fear, because it's been shown in, you know, outside of the cancer context and other sorts of disease that are affecting the brain and mental health as well. And also, you mentioned something interesting. You said that exercise seems to help cancer patients feel like they have control of their lives, right? Because I could imagine a cancer diagnosis does feel like you lose complete control of your life. I mean, it's very scary. And so I wonder also just if there's almost a placebo effect. A placebo effect is a real biological phenomenon, as you know. I mean, changes in immune system, dopamine, a lot of things are happening when you have a positive outlook, when you feel like you have control of something. And so you almost wonder if that spills over to some of the psychological effects helping the anti-cancer effects as well. Like, there's probably some crossover there. Yeah, I think that's definitely part of the explanation is some of these benefits. But as you know, there's good biological effects as well on depression, on neurotransmitters, these types of things. So there's a biological basis for some of these improvements in things like anxiety and depression. But some of these other improvements, things like self-esteem is just patients feeling better about themselves because they're doing something that they believe is helping themselves. So these are all important psychological changes. And the big difference, you know, we look at all those literatures outside of cancer related to depression and cognitive function and anxiety and so on. But in patients, you know, you're dealing with depression based on a cancer diagnosis and depression based on treatments and stuff. So what we've been able to show is exercise helps with the anxiety, the depression, and the stress associated with a cancer diagnosis and treatments and side effects that we weren't sure they were going to help with. So it really helps manage some of that psychological stress caused by the cancer and its treatments. Well, it sounds to me like the bottom line is, I mean, at every stage, exercise is something that people need to absolutely focus on for cancer prevention, for cancer treatment, and continuing treatment. So, you know, it not only is helping you get through the treatment, perhaps, you know, even having beneficial outcomes, you know, with reducing mortality risk, reducing cancer recurrence. But that psychological, let's say you, okay, you get through the treatment, you got rid of the cancer. Okay, it's gone. And some people might think, okay, end, end there. I'm done. But the reality is then you do have to keep going back for these screenings. you do have to worry about a few of those tumor cells that escaped and maybe, you know, are going to continue growing at the tumor site or somewhere else. And so having exercise as a part of your daily routine is going to make everything easier. And it's going to improve the chances that you're not going to have cancer recurrence. So there's every reason to exercise and every, you know, there's every reason to be motivated to exercise. Yeah, we think about it, exercise having benefits across the continuum of cancer care. So from the time of diagnosis and for the balance of life. So the initial diagnosis, helping you prepare for treatments. Once you start treatment, help you get through those treatments and complete those treatments. Afterwards, we're looking at recovery from those treatments. And then after treatments, when you're in what we call the survivorship phase, reducing the risk of recurrence, but also reducing the risk for other chronic diseases. So, unfortunately, many of the treatments that cancer patients get increase their risk for cardiovascular disease. Some of these drugs are cardiotoxic, increase the risk of osteoporosis, they increase the risk of diabetes. So now you've kind of survived your cancer, but now you're trying to prevent some of these secondary diseases that might occur. So there's lots of good reasons to exercise right across the cancer trajectory. Before, we wanted just a couple of rapid-fire questions. Is there anything that we didn't cover, perhaps, that might be important to discuss? I mean, the other way I think about exercise in terms of its importance, when you look at what's currently being done for cancer patients, because a lot is being done. So they're offered a lot of other complementary therapies, art therapy, music therapy, acupuncture, massage therapy, psychological counseling, stress management. And these are all having benefits on symptoms, side effects, quality of life, just like exercise. But none of those other interventions have shown any benefits for survival, any benefits for the disease itself or risk of recurrence. And then you look at the treatments we give for cancer, like chemotherapy, radiation therapy, all those interventions benefit the survival side of things, but they oftentimes undermine quality of life. They make symptoms and side effects worse. Exercise is one of these few interventions potentially for patients that can help both with quality of life, side effect symptoms, and also improve disease-free survival. So it's a real win-win compared to many of these other interventions that we offer cancer patients. Do you have any idea what percentage of people that are diagnosed with cancer actually do use exercise in conjunction with their treatment? Yeah, we've done a lot of those surveys. And what we show is, just to give you the pattern of it, we asked many of these long-term survivors what they were doing before diagnosis, what they were doing during treatment, and what they were doing after treatment. And what all this research shows is that a cancer diagnosis and treatment has a very negative impact on exercise levels. All of these patients report doing dramatically less exercise during treatment than they were doing before diagnosis. After treatments and survivorship, exercise will tend to increase back, but not back to pre-diagnosis levels. So it's like the diagnosis and treatment of cancer is kind of having a permanent negative impact on exercise levels. So what this tells me is that if we don't intervene, we're not helping patients exercise. If oncologists and cancer centers aren't working with patients, the natural response of anyone diagnosed with cancer is to sort of give up exercise, get through these treatments, and try and recover afterwards."