Heat training – either riding in warmer climes or wearing extra kit to raise your body temperature – is becoming increasingly popular in the pro cycling ranks.
So, should amateur riders also be turning up the heat on our training sessions?
To answer whether heat training is something you should be adding to your winter training schedule, the BikeRadar Podcast welcomes Dan Loran, coach at Red Bull-Bora-hansgrohe and Puck Alkemade, who heads up the research and physiological development department at body temperature sensor manufacturer Core.
What is heat training?
Alkemade: Heat training is, in essence, the act of making your body hotter than it would usually be when exercising.
you'll either train in a hot environment, or you'll train with additional clothing on. The aim is to get your body hot. So, when you do this, your core temperature and your skin temperature will increase.
The aim of a heat session is to get your internal body temperature to between 38.3 and 38.7ºC. You then moderate your effort to maintain this temperature for anywhere up to an hour.
To measure skin and core body temperature, many riders are using Core’s device, which can display skin and core temperatures along with a heat-strain index figure on a compatible cycling computer.
How are the pros using heat training?
Loran: During the season, riders will use heat training over a period of two, three or even four weeks, primarily focusing on indoor sessions. What we are doing is using it following an altitude camp.
The riders go to altitude for a few weeks, come back down to sea level and we continue with some heat training to preserve, or even amplify, the effect of altitude.
At the beginning of the season, instead of attitude training, we set heat training blocks to try to increase hemoglobin mass in that way. But I also have to say it's really individual for the rider’s physiology and race programme.
What are the benefits of heat training?
BikeRadar: An increase in hemoglobin mass should effectively increase your ability to transport oxygen to your muscles and thus improve your performance. We’ve seen it quoted that it's possible to get around a 2.5 per cent increase in hemoglobin mass from this kind of heat training. Is that true for all riders?
Loran: It varies based on the individual. Hemoglobin mass could increase by two, three or just 0.1 per cent. Hemoglobin mass means that you probably have a higher potential to produce more power, but it does not mean that you automatically produce more.
There is certainly a higher potential and that's why we are looking to do heat training. For other riders, a different form of training could be more effective. You can never combine everything together, so you really have to take care about the tools you are using.
We are using heat training because the science says that it really works and, as a coach, I tried it several times with some athletes in cycling and also in other endurance sports, and it works pretty well.
Traditionally, this has been used as a preparation for training and racing in the heat. More recently, it's also shown that this can enhance performance in cooler environments.
It depends on the period where you are, so I think there are different ways or different reasons to use heat. So one could be, for example, just using heat training to have an increase in hemoglobin mass without any other issues. So without altitude or without natural heat from outside.
What could an amateur rider expect to gain?
While individual responses to heat training adaptations will differ, we wanted to know what an amateur with a 300-watt FTP (Functional Threshold Power) might gain from five weeks of heat training.
After a little persuading, Dan suggested that our theoretical rider might expect to gain up to 10 watts on their FTP, or a 3.33 per cent increase.
Given that studies have shown riders gaining anywhere up to 10 per cent on their FTP, the gain could be as high as 30 watts for our rider.
This is highly dependent on the individual’s response to heat training, but such a significant increase is certainly tempting when you consider the time efficiency of the training.
How does heat training fit into a regular week?
Given the stress this will place on your body, both Loran and Alkemade advise a gradual increase in session duration.
Once you’re comfortable doing the heat training, Loran says the most practical way to train is to use an indoor trainer because this is the most controllable environment.
His advice is to target heat training in two-to-three week blocks for pure heat adaptation purposes, adding sessions where you can on top of your regular training. You can build these blocks up to four or five weeks as you become more experienced with heat training.
Alkemade says that to increase your hemoglobin mass, a rider may need to extend a heat-training block to five weeks, with five sessions each week. As a result, it's a serious commitment.
Loran adds that it’s important to remember the aim of the heat training is to bring your core temperature up to around 38.3 to 38.7ºC and maintain it in this range for 30 to 80 minutes.
To do this, he says, you may need to gradually reduce your power output over the course of a session.
Alkemade offers a word of caution, though, saying: “The big danger is always that you overdo it. You often find people who just dive in too quickly and you can easily overdo the training there – and then you have a negative effect. And that's why it's so important to have an easy way to control what you are doing”.
For an introduction to heat training, Core has a handy five-week plan to get you started.
For more advanced riders, Loran suggests adding a heat session immediately after an outdoor endurance ride of three to four hours. That said, you’ll need mighty amounts of willpower.
Does heat training impact males and females differently?
Alkemade: A study actually found similar responses between male and female riders. They found approximately a three to four per cent increase in hemoglobin mass, which I think translated into something like a six to 10 per cent performance increase.
The difference, however, was not significantly different for either men or women.
I would say, in general, there are a lot of individual differences within males, but also within females, so I wouldn't say there is any clear male-female difference.
What do people need to get going?
To complete a heat training session accurately, a body temperature sensor is needed. Core supplies one of the only commercially available sensors, although at £230 / $285, it isn’t a cheap device.
The sensor works via an app, although it can also display data on a compatible cycling computer.
Additionally, most heat training sessions suggest monitoring your effort and progress with a heart rate sensor and power meter, although these are optional.
To get your body temperature elevated to the correct zone, you’ll likely need some winter clothing, while an indoor trainer makes for the most controllable environment.
If you have all of the above, all that’s left to do is get sweaty.
