 How much does riding in cold weather affect your cycling performance and what can you do about it? We'll be tackling this question by taking a look at the science on how riding in the cold may negatively affect your muscle force production, lactate threshold, ventilation, and fatigue. And we'll also be talking about getting sick while training in the winter, ways to prevent it, and how to adjust your training schedule if you do get sick. Welcome to another video. My name is Dylan and I'm a cycling coach at CTS. And for weekly science-based training, racing, and gear related videos, be sure to subscribe. And if you have a training question or a topic you'd like to see me cover in a future video, be sure to leave it down in the comments section below. I do my best to get to all the questions in the comments. This summer I did a video on how riding in the heat affects your cycling performance. Spoiler alert, if you haven't seen it, riding in the heat has a big negative impact. For example, in this study on the effects of heat stress on exercise performance in an elite cyclist, they found that mean power decreased by 6.5% or 22 watts when subjects rode in the heat. Most people intuitively already know that riding in hot weather decreases their cycling performance. All they have to do is go out for a ride on a 100 degree day and experience how awful that feels. For us riders in the Northern Hemisphere were in the midst of winter and were experiencing the opposite problem. And while the performance detriments of riding in the cold aren't as apparent as riding in the heat, at least in how they make your body feel, they are very real. Before we get into the physiological effects of cold on your body, let's start by addressing the fact that cold air is denser than warm air and therefore you won't travel as fast through it. But is it really enough to make a difference in your average speed? Let's head over to bikecalculator.com to find out. Let's say you're doing a flat 40 kilometer ride at 250 watts at a temperature of 35 degrees Celsius or 95 degrees Fahrenheit. This would take you 68 minutes and 42 seconds. Now let's say you did that same ride but it was 0 degrees Celsius. That same ride would take you 71 minutes and 23 seconds to complete. That's a 2 minute and 41 second difference just due to temperature and funny enough that's a bigger difference than upgrading to an aero helmet, aero wheels, and an aero frame combined. This is why for example when Bradley Wiggins broke the hour record, they reportedly had the heat cranked up to 30 degrees. On top of this, wearing bulky clothing in the winter only adds weight and aerodynamic drag further slowing you down. Simply put, if you're a Strava KOM hunter, the winter is not a good hunting season. Well dang it bro, is it even worth riding then? So the cold affects average speed but what about physiologically? Is there a reason why I'm struggling to put out power in the winter? Or could it just be the fact that I did a lot more eating over the holidays than I did riding? Let's jump into the science to find out. This study on the effect of temperature on prolonged cycling performance tested performance at a variety of temperatures from 3 degrees to 30 degrees Celsius. Sounds like a pretty miserable study to participate in. Anyway, they demonstrated that there is a clear effect of temperature on exercise capacity which appears to follow an inverted U relationship. This means that there's an optimal temperature for performance both too cold and too hot had a negative impact on time to exhaustion and the temperature at which subjects performed the best was around 10 degrees Celsius or 50 degrees Fahrenheit. This was taken into account during the INEOS 159 challenge where Iliad Kipchogi ran the first sub two hour marathon. They were very careful to pick a cool day to ensure optimal performance. Interesting that they went for the opposite approach to Bradley Wiggins hour record and determined that the optimal physiological conditions would produce a faster time than the optimal physical conditions which probably is the case when you're running instead of cycling for double the time no less. So what exactly is the reason for this loss of performance in cold weather? One explanation could be the decrease in the amount of force a cold muscle is able to produce. This study on muscle temperature and maximal muscle strength found that muscle strength and performance in jumping and sprinting exercises was significantly reduced with lower muscle temperatures. A low muscle temperature has also been shown to hinder cycling performance. In this study for example they had subjects cycle at 350 watts until exhaustion with a muscle temperature of 29 degrees and 34 degrees Celsius. They found that maximal work time was considerably shorter when subjects had a lower muscle temperature. The subjects had a higher lactate concentration post exercise with cold legs leading to the conclusion that the reduction in performance observed at low temps may partially be explained by an increased accumulation rate of lactate. Basically your lactate threshold is actually lower when your legs are cold. On top of this intense exercise in the cold may affect our ventilation. Many people report having a hard time breathing when exercising in the cold and it may not just be in their head. Acute or chronic cold exposure elicits several effects on the respiratory system. Pulmonary mechanics are compromised by bronchoconstriction, airway congestion, secretions, and decreased mucociliary clearance. These responses are active in cold or exercise induced asthma. I myself get a bad cough that lasts for one or two hours after a long ride in the cold and I know others that experience the same thing. This is exercise induced asthma and it's made worse by riding in the cold. Increased levels of fatigue are also a consideration when riding in the cold. This study on cold muscle function in fatigue hooks subjects up to an EMG and had them perform 20 minute workouts to measure the fatigue in cold and warm muscles. What they found was higher levels of fatigue in cold muscles. It also turns out that cold muscles may increase the likelihood of muscle tears. From this study on muscle tears due to temperature, they stated when muscle temperatures drop below 32 degrees Celsius, less energy is required to cause muscle tears. Muscle temperatures of 32 degrees Celsius are reported in ambient conditions, suggesting that it would be beneficial particularly in colder environments to ensure that peripheral muscle temperature is raised close to core level prior to high velocity exercise. And the icing on top of this horrible frozen cake is that hard training in the winter when the cold and flu are running rampant only suppresses your immune system and getting sick will have the biggest impact on your performance. From this article on marathon training and immune function, many components of the immune system exhibit adverse changes after marathon type exertion. Many mechanisms appear to be involved including exercise induced changes in stress hormone, cytokine concentrations, body temperature changes, increases in blood flow and dehydration. During this open window of immune dysfunction which may last between 3 and 72 hours depending on the immune measures, viruses and bacteria may gain a foothold, increasing the risk of subclinical and clinical infection, and further research confirms these findings. Both of these reviews suggested preventative measures for athletes which I'll get into in just a minute in the solutions half of this video. Alright so what can you do about all this? Well according to this review on physiology of exercise in the cold, you could just pack on the pounds. The amount of heat lost conductively to the environment through tissue depends upon factors such as subcutaneous fat. Thus individuals with higher levels of fat are generally better able to maintain their core temperature in cold environments. Oh sweet yeah that makes sense you know that's totally why I'm 20 pounds overweight right now you know I'm just trying to stay warm. In all seriousness though all of these studies made sure that the muscle temperature of the subjects was cold but just because you're exercising in the cold doesn't mean your actual muscles have to be cold. This study on the effect of leg covering on muscle activity in cool environments tested subjects in five degrees celsius while wearing shorts, pants or pants with one leg cut so it's pants on one leg and shorts on the other leg. They found that mean power was higher when subjects were pants and they concluded that the EMG activity of the uncovered legs implied greater strain in cold conditions. This is where riding in the heat and riding in the cold differ. When it's hot out it's very hard to keep your core temperature cool so the solution is to acclimate to the heat by riding in the heat. With the cold however acclimation doesn't appear to improve performance when riding in the cold. However you can raise your body temperature in the cold simply by putting on extra clothes. Yup the solution is exactly what you've been thinking this whole time just dress properly. Wow seriously dude thanks for wasting 10 minutes of my life I almost fell asleep like 10 times when you started reading studies again. This seems simple yet I still show up to winter group rides and see people with bare legs. And you know what to be honest I used to be that guy but now I'm the guy that wears leg warmers on a 68 degree day. Think of this video as a public service announcement to keep your legs covered. Now I'm not going to show you how to put a leg warmer on because I'm sure GCN already has plenty of videos about that but here are my suggestions. Wear leg warmers even when you feel like you won't need them. Better safe than sorry. I usually have leg warmers on up to the high 60s Fahrenheit or 20 degrees Celsius. Of course make sure that your core temperature is warm. Because if your core isn't warm then the rest of your body won't be either. Again better safe than sorry and in this case better to be a little sweaty than shivering. A good warm up is always important but especially for cold conditions to bring your muscle temperature up before you start working hard. And in fact for very hard races like cross racing for example you may be able to forego leg warmers as long as you get in a solid warm up depending on conditions of course. Finally let's address what you can do to prevent getting sick in the winter as an athlete. Going back to the article on marathon training and immune function of the various nutritional and pharmacological countermeasures to marathon induced immune perturbations. Ingestion of carbohydrate beverages during intense and prolonged exercise has emerged as the most effective because carbohydrate ingestion attenuates increases in plasma cytokines and stress hormones. These findings were confirmed in this review that stated that consuming carbohydrate during prolonged strenuous exercise attenuates rises in stress hormone and appears to limit the degree of exercise induced immune depression. Other nutritional considerations may be adequate intake of iron, zinc and vitamins A, D, E, B6 and B12. There you go just one more reason to carb up while riding. Perhaps the keto flu that keto heads talk about is just you know the actual flu. Of course all the usual healthy habits to prevent getting sick apply as well but carbohydrate intake is an endurance athlete specific measure that you can take. Also if you do get sick lay off of hard training until you get better. I've learned this the hard way as I've had the common cold for over a month because I was too stubborn to take a break. A week off the bike or just doing easy rides because you're sick is better than a month of mediocre training because you're still sick. Alright that wraps up this video. Thanks for watching. I hope you guys found this information helpful. If you like this video be sure to give it a like, share it with a friend and subscribe. Training plans are available and if you're interested in getting a CTS coach you can save $40 when you sign up by using my code CTSDJ. Links for both are down in the description.