 With the worldwide coronavirus outbreak and the cancellation of any and all cycling events in the foreseeable future, should we be adjusting our training and is it even a good idea to be training right now or will that put our immune systems at risk? We're going to jump into the science on how training affects your immune system and I'll talk about how to adjust your training accordingly given this year's shifted cycling schedule. This is one of those cases where actually taking a look at the science completely shattered my preconceived notions on this topic, so you won't want to miss this. Welcome back to another video. My name is Dylan and for weekly science-based coaching videos just like this one be sure to subscribe. The outbreak of COVID-19 is having a huge impact on our daily lives as I'm sure you already know. Dude, tell me about it. I can't even talk other bike racers on Facebook anymore because every single post is about coronavirus and from reading those posts I can't tell if we're all going to die or if we all just need to calm down. For some cyclists riding a bike right now is understandably the least of their concerns, but for many of us riding is a part of our day-to-day life and it can be difficult to know how to adjust your training or whether or not we should be training at all right now. This is what we'll be discussing today. Let's first get into the science on how hard training affects your immune system. It's a pretty widely held belief amongst athletes that a hard workout or a race compromises your immune system and many athletes report getting sick after racing. Interestingly enough though there's a lot of research out there that contradicts this belief. For example, this study on exercise and immunity to the influenza vaccine in older individuals categorized subjects into one of three groups active, moderately active or sedentary and then tested them two weeks after influenza immunization. The results showed that physically active participants had the best immune response and concluded that the practice of regular vigorous exercise was associated with enhanced immune response following influenza vaccination and this isn't the only study coming to this conclusion. This study also found that exercise enhanced immune health in older subjects following the flu vaccine. These results have been found in animal studies as well. For example, this study looked at the survival rates of active versus inactive mice after being infected with salmonella. They found that active mice had a better survival rate than the sedentary mice at 34 out of 77 versus 23 out of 79. Old people in mice? Is that the best you got? I'm a dedicated athlete who works my body to the point of exhaustion on a daily basis and I know that's why I get sick all the time. Of course, celebrating my mid-pack Zwift race finish at the bar every night probably doesn't help. I had this same skepticism when reading these studies. Of course, living an active lifestyle is good for your immune system but what about putting your body under a considerable amount of stress like we do when we race or do a hard workout? Surely that can't be good for your immune system, right? This study on infectious episodes in runners before and after a race compared the incidence of infectious episodes in 273 runners during the training period before and after a 5k, 10k, or half marathon race. What they found was that 34% of the runners who had trained less than 15 hours per week had at least one infectious episode compared to only 25% for runners who trained more than 15 hours per week. Basically, those who trained more got sick less. On top of this, during the week following the road race, runners did not report an increase in infectious episodes as compared to the week prior to the race. They concluded that runners with a more serious commitment to regular exercise may experience less infectious episodes than recreational runners because of both direct and indirect effects on immunosurveillance. In addition, the stressful race experience does not appear to increase risk of acquiring an acute respiratory infection. And again, it's not just one study coming to this conclusion. This study reported better immune function in marathon runners over sedentary controls. And both these studies on large groups of ultramarathon runners reported that these athletes report fewer misdays of work or school due to injury or illness. Although on a side note, they do appear to have more stress fractures involving the foot, which is absolutely shocking news to hear from a group of people that run 161 kilometers for fun. In all seriousness, if any athletes are severely stressing their body through exercise, it's ultramarathon runners. And it appears that they're as healthy if not healthier than the general population. Why is this? Most athletes will tell you that training compromises their immune system. However, when you look at the science, this doesn't appear to be the case. If anything, exercise is immune boosting. In this 2018 review on debunking the myth of exercise-induced immune suppression, they deconstructed the open-window hypothesis that states that a short window of time after exercise, your immune system is compromised. As it turns out, limited reliable evidence exists to support the claim that vigorous exercise heightens risk of opportunistic infections and the dramatic reductions to lymphocyte numbers and function one to two hours after exercise reflects a transient and time-dependent redistribution of immune cells to peripheral tissues, resulting in a heightened state of immune surveillance and immune regulation as opposed to immune suppression. Basically, it's a misconception to label any form of acute exercise as immunosuppressive. Instead, exercise most likely improves immune competency across the lifespan. To be fair, there is research out there that supports immune suppression with exercise, but these studies are few and far between. The balance of evidence shows that exercise is beneficial to your immune health even when that exercise is long in duration or high in intensity. Getting sick after a race could be caused by a number of factors, like stress, travel, lack of sleep, or simply being exposed to more people. So in short, should you stop riding your bike so you don't suppress your immune system during the coronavirus? No, not at all. If anything, you should continue riding your bike to improve immunity, especially in this time of high stress. This study on physical activity, stress and self-reported upper respiratory infection, found that highly stressed people, particularly men, appear to benefit more from physical activity than those with lower stress levels. Now, some countries like Italy and Spain are currently not allowing cycling outdoors, not because they're worried that cyclists will catch the coronavirus while riding, but because they want to minimize the number of hospital visits from people in cycling-related accidents. This is also the idea behind the flat and the curved slogan that you've been hearing. If we all practice social distancing, then coronavirus won't spread as fast and we won't overwhelm our healthcare system. This is super important right now and is the reason for races being canceled and also why you should probably stay away from big group rides or ride indoors, but it's also a good reason to be especially careful if you do decide to ride outside. The last thing that you want now is a trip to the hospital, both for yourself and for the people suffering from the virus who require hospitalization and need treatment. Wait, so you're saying I shouldn't attempt the double black diamond drop on Farlow for the first time on my hashtag solo quarantine ride? With all that being said, the race season or for those of you who don't race, the group ride slash let me show my riding buddies how much faster I am than them season is canceled for the foreseeable future. Many of you have been training all winter in preparation for this and now you've got no but to kick. What do you do now? Do you keep training full steam, adding intensity to your training program as if racing is right around the corner, or do you hold off and revert back to base training mode or even off season mode for that matter? Here are my suggestions. Maintaining intensity for too long will lead to a fitness plateau. This is why we generally do it in the months preceding the race season. Given that there won't be any racing for some time now, I would hold off on making intensity the focus of your training. Many of the races that were scheduled for the next couple months, if they weren't just outright canceled, are now rescheduled for the late summer or fall. If the race season even ends up happening, those races will of course run on top of the races that are already scheduled for that time of year, meaning that'll be a very busy time for racing. If you are planning on racing this year, that's your new season and when you want to peak. That effectively means that right now is the base season. Some of you have already been racking up big miles over the winter for months though. Should you just continue doing that or perhaps do something else? Here are the two approaches that I'm taking with the athletes that I coach. If you've been training hard all winter, revert back to off season mode. Why should you do this? Because pushing yourself for months with no break will likely lead to a plateau or burnout, and by the time you get to September, you'll be struggling. There's a couple reasons for this. One explanation could be changes in blood values. This study looking at blood parameters of top level cyclists over the course of a year found that hematocrit and hemoglobin concentration decreased throughout the season and then returned to baseline level in the off season. That jump back up you see in November is when pros commonly take a break. There's also exercise induced changes in hormone levels. For example, this study on hormone responses of pro cyclists during competition looked at nine riders from two teams during the Vuelta. Blood samples from these riders were taken before the race and then after week one, two, and three. What they found was that starting testosterone levels were lower in the team that had more racing days in the previous month, and testosterone further decreased in both teams each week throughout the race. Now of course, this is over a three week grand tour and most of us don't train that hard. However, similar results have been found for other forms of exercise as well. This study on the effect of detraining on power athletes found that after 14 days of detraining, levels of growth hormone and testosterone significantly increased while cortisol and creatine kinase levels decreased. The message here is that if you've been training hard, take a little break, perhaps do some cross training, focus on strength, but whatever you do reduce your training load. At this point you've got months before you can race and if you keep it up at this rate the new adjusted race schedule will likely not go well for you. On the other hand, if you had a slow start to the season and you're just now starting to pack on miles, then lucky you, you have more time. A lot of us are working from home right now. Hopefully that means you have more time to train. Either way I'd focus on getting in a large volume of zone two work, either alone or at least six feet from another rider or on the trainer. Great time to work on that mental fortitude. Thanks for watching. Everybody stay safe and stay healthy out there. I'll try to see if I can put out videos more frequently for you guys to watch while you socially isolate yourselves. If you like this video be sure to give it a like, subscribe, and share it with your cycling friends. I'll see you in the next one.