 Hey what's up everyone welcome to another video my name is Dylan and I'm a cycling coach at CTS and today we're going to be talking about how to deal with heat as a cyclist. I'll be talking about how riding in hot conditions affects your performance and what you can do about it. I'll go into heat acclimation, how much of an effect it has, how long it takes to heat acclimate and various heat acclimation methods and then I'll talk about various cooling methods and how much of an impact they have on your performance on race day. If you're new to this channel I make weekly training, racing and gear related videos going over tips and tricks that I've learned in my 12 years of training and racing experience and as a cycling coach at CTS. If you want to learn how to get faster or just more about the science of training in general then 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 then be sure to leave it in the comments section down below. I do my best to get to all the questions in the comments. Let's start the video off by talking about what kind of effect riding in high temperatures has on your body. I'm sure we've all felt a loss of performance when riding in the heat but exactly how much of a loss of performance are we talking about. In this study on the effects of heat stress on exercise performance in elite cyclists they took 11 cyclists from the Australian national team and had them complete time trials at 32 degrees and 23 degrees Celsius or 90 and 73 degrees Fahrenheit respectively. What they found was that mean power decreased by 6.5 percent when subjects rode in the heat. 6.5 percent is a substantial decrease and in the case of this study that translated into a 22 watt decrease in 30 minute power. It's also important to note that as the testament on the power during the hot condition dropped lower and lower while the profile during the control trial stayed mostly steady. This makes sense because the longer you ride in the heat the higher your body temperature will get, the more dehydrated you'll get and the lower your power will be. Many people will notice that their heart rate while riding in the heat is higher as well. This isn't just in your head. This study on the relation of heart rate to VO2 peak during exercise in the heat showed substantial increases in heart rate during submaximal exercise as the temperature increased. In fact at 25 degrees Celsius the subject's average heart rate was 107 beats per minute and bumping the temperature up to 45 degrees Celsius increased their average heart rate to 137 beats per minute. Decrease power and increase heart rate sounds like a recipe for a bad day on the bike. Yeah that's definitely why I haven't gotten a KOM on Strava all summer. It's just been too hot. So what can you do to combat this? Well you may have noticed that as you ride more in the heat you get more used to it. This isn't just your body giving into hot conditions and accepting them. Your body actually makes adaptations that allow you to perform better in the heat. Much like going to a higher elevation would allow your body to acclimate to higher altitude. In this study on heat acclimation and exercise subjects cycled for nine to twelve days at 40 degrees Celsius or 104 degrees Fahrenheit while the control group performed the same procedure at 20 degrees Celsius or 68 degrees Fahrenheit. The results showed that those who exercised in heat approximately doubled their endurance time from 48 to 80 minutes on average while the control group saw no improvement. One explanation for this could be increased sweating with acclimation both in sweat rate and sweat sensitivity. The heat acclimated subjects were also able to reduce that rise in heart rate that we see when exercising in the heat from 164 beats per minute in the first trial to 153 beats per minute after acclimation. Other markers such as cardiac output, stroke volume, skin temperature, and plasma volume were all improved after acclimation as well. So heat acclimation can improve your performance in the heat. Intuitively we probably already knew that but what about your performance in cooler conditions? Will heat acclimation have any effect on that? This study on heat acclimation and athletic performance took 12 trained cyclists and assessed time trial performance and lactate threshold in both cool and hot environments after 10 days of heat acclimation. What they found was that measures like VO2max, lactate threshold, cardiac output, and time trial performance were all improved with heat acclimation in both hot and cool conditions while the control group that was not heat acclimated saw no improvement. The study concludes that they conclusively demonstrate that heat acclimation can improve aerobic exercise performance in cool temperate conditions and that these heat acclimation benefits may be retained for one or two weeks. Okay so some clear benefits to heat acclimation even if you aren't racing in the heat. But if you want to get heat acclimated exactly how long is it going to take? This meta-analysis on the effects of heat acclimation on exercise performance in the heat reviewed 96 articles and found that 7 to 14 days was the most common duration for heat acclimation however longer regimens were more effective than shorter approaches. They conclude that heat acclimation lasting less than 14 days results in many physiological and perceptual adaptations however the extent to the adaptations is greatest when heat acclimation regimens last longer than 14 days. What are some practical things that you can do to get more acclimated to the heat? Well for starters simply ride in the heat. Many of these studies simply had their subjects perform their workouts in the heat to induce heat acclimation. In the summer a lot of people like to avoid the hottest part of the day by either riding early in the morning or late in the evening and if it's a particularly hot day they might just skip a bike ride altogether. To get the greatest effects of heat acclimation you want to embrace the heat and make sure that you ride during the hottest part of the day and if you see a particularly hot day coming up maybe you schedule a long ride on that day instead of skipping it. What if you don't live in a hot environment? Well one thing to consider might be riding indoors anybody who regularly rides the trainer knows how hot and sweaty you get while you do it. Tony Martin reportedly rode his TT bike on the trainer in a heated room in his preparation for the 2016 world championship time trial in Qatar. Temperatures for that race were 40 degrees Celsius or 104 degrees Fahrenheit and unsurprisingly he went on to win that race. Some riders have also been known to wear many layers of clothing even when it's already warm outside and heat acclimation doesn't have to just come when you're riding your bike. I don't use air conditioning in my house and while it can be uncomfortable to constantly sit in a pool of my own sweat and smell like an old gym bag it can help with your performance on the bike. Wow Dylan I bet you are really popular with the ladies. Many riders have also turned to using saunas as a method of heat acclimation. In this study on sauna based heat acclimation they put seven well-trained cyclists through 10 days of sauna training which consisted of 30 minutes in the sauna each day immediately followed by normal training. They found that the plasma volume increased by almost 18% after the sauna protocol which is one of the physiological changes that your body makes with heat acclimation. Using these methods together may be even more beneficial. If you know you have a hot race coming up embrace the heat both on and off the bike and your result will likely be better because of it. All right that's all the things that you can do to help prepare yourself for the heat but let's say now it's race day and it's an absolute scorcher. What are things that you can do to help mitigate the effects of the heat? Uh use the heat as the excuse for why I got dropped. There's evidence to show that various pre-cooling methods and cooling yourself off during an event have significant effects on performance. For example in this study on the effect of cooling vests on 5k performance they took 17 competitive runners and had them run two 5ks at 32 degrees celsius, one while wearing just a t-shirt during the warm-up and one while wearing an ice vest during the warm-up. What they found was that 5k runtime was significantly lower by 13 seconds when subjects wore the ice vest with a faster pace most evident during the last two-thirds of the run. Ice vests are one way of cooling yourself prior to an event during the warm-up but mid-race cooling methods have also been shown to be effective. In this study on the effect of neck cooling on running performance in the heat seven non-acclimated subjects performed three 90-minute time trials in the heat. During one they wore a cooling collar from the start, for another they wore a cooling collar that was replaced every 30 minutes and they also tested no cooling collar. They found that in both trials that used a cooling collar subjects performed significantly better than in trials where they did not have the cooling collar. It's hard to say whether or not these cooling methods are actually having a physiological effect or maybe they're just making it mentally easier to deal with the heat. The study concluded that cooling the neck region does not alter the physiological or hormonal response to running exercise performed in high ambient temperatures however it does improve the subjective rating of thermal comfort and this improvement in thermal comfort may improve performance by masking the thermal strain of the body. When looking at a meta-analysis of many studies on various cooling methods they found an average of 6.7% improvement with pre-cooling and per-cooling methods. Pre-cooling methods included water immersion with an average of 6.5% increase in performance, cold water or ice ingestion with 6.3% increase, cooling packs with a 4.3% increase in performance, and cooling vests with a 3.4% increase. During exercise cooling methods include cooling vests with a 21.5% increase in performance, cold water ingestion with an 11% increase in performance, and the use of cooling packs with an 8.4% increase. In summary the best way to perform well in the heat is to embrace the heat during training and then do the exact opposite on race day. Acclimating to the heat can have a large effect on performance not only in hot conditions but also in cooler conditions. Acclimation will probably take one to two weeks but longer is better. Good ways of acclimating to the heat include riding during the hottest part of the day, riding indoors, wearing more clothes than you need on your ride, using saunas, and perhaps if your family doesn't kill you for going AC. When it comes to race day in the heat the exact opposite is true. It's all about staying as cool as possible prior to and during the event with ice vests, ice packs, perhaps pouring cold water on yourself, putting ice in a sock and putting it in your jersey on the back of your neck, etc. These cooling techniques have a real impact on your performance and should be considered in your race strategy. If you're doing a lap race, have a cooler ready to go with ice packs and cold water to pour on yourself when you stop. If your race has aid stations then be sure to pour cold water on yourself before you leave the aid station. Now obviously a huge factor that influences performance in the heat is hydration and I didn't mention any of that in this video because I feel like I could probably fill up a whole video just talking about hydration. If you guys want to see a video like that let me know down in the comments. Also as I record this video it's probably about 85 degrees in here so if I look sweaty it's only because I'm taking my own advice. Thanks for watching and I hope you guys found this information helpful. If you like this video be sure to give it a like, share with a friend, and subscribe. And if you want to see more training and racing content be sure to follow me on Instagram, Twitter, and Facebook. If you want to check out my training be sure to check me out on Strava. 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