Cycling in the heat

Cycling in the heat

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As cyclists, we all look forward to the long summer evenings, the feeling of the sun on your back as you ride and reaping the rewards of those tough winter miles. However, the summer months present their own challenges to riders, so how can you ensure that you don’t suffer in the heat.

Stay hydrated

Hydration is a slightly controversial area in sports science with some recent research suggesting that hydration isn’t quite as crucial to performance as was previously thought. However there is still considerable evidence and hours of rider feedback at the highest levels of the sport that backs up the importance of staying optimally hydrated. It is possible to over-drink but, for the majority of riders tackling Sportives or long training rides in the summer, under hydration is far more likely to be an issue.

Follow our advice for maintaining optimal hydration, experiment in training to tweak these guidelines to find the volume and concentration of fluids that work best for you and apply your findings to your key events.

A top tip for keeping cool is to freeze your second bottle so that, by the time you come to drink it, it has thawed but will still be cool. Don’t fill the bottle fully before freezing though as the contents will expand, so only fill it three-quarters.

Adjust your pacing

If you are not well acclimatised to the heat, you will need to adapt your pacing strategy to compensate. Ride to the lower ends of your normal training zones, whether using heart rate or power, and, on long rides, pace ultra-conservatively early on until you have an idea of how your body is reacting to the heat. This especially applies to long climbs where your lower speeds mean you won’t benefit from the cooling effect of a headwind.


If you know you have got an event coming up abroad where the conditions will be hot or humid, you might want to consider adopting some form of acclimatisation protocol. The ideal is to head out 7-14 days before the event but, unless you are a professional athlete or have a very understanding boss and family, this is unlikely. You can however derive acclimatisation benefits by training indoors at home, such as a turbo in the bathroom, and mimicking the conditions you are likely to encounter. Begin this process 7-14 days out from your event and, for the first 3-5 days, just train gently and for relatively short periods in the warm conditions and save longer and harder efforts for outdoors. Throughout the acclimatisation process, closely monitor your hydration levels and ensure fluid and electrolyte intake are optimal. After 5 days, aim to be riding for at least an hour in the heat and, if your recovery is good and you are maintaining hydration levels, consider two workouts per day. Try to schedule so that you arrive in the location of your event three days beforehand but, if this is not possible, continue your home acclimatisation until the day before you travel.

Avoid the hottest part of the day

Unless an event forces you to ride through the middle of the day in the summer, try to ride in the mornings or the evenings when the sun is less intense. This particularly applies if you have got some higher end efforts to tackle and you should also seek out routes that have some shade.

Dress for the heat

Choose a quality wicking short sleeved cycling jersey with a full length zip. A string or mesh vest will enhance the wicking process and, as it will keep you drier, will help prevent chilling on long descents. Even if it is a scorching day, especially if you are heading into the hills or mountains, always pack a lightweight windproof gilet for those descents or in case the weather unexpectedly changes.

Unvented helmets may give you a small aerodynamic edge but, in the heat, that time saved will rapidly disappear if you start to overheat. Choose well vented shoes and pair them with quality wicking socks.

What to eat?

The snacks that fuelled your rides during the winter and spring just might not appeal in hotter conditions. Look for gels that are more liquid and reduce the concentration of your energy drinks. Experiment in training and consider some savoury options, such as these rice cakes.

Slap on the sun cream

The dangers of over exposure to the sun are now well known and should be avoided. Use a quality sweat and water resistant sunblock with an SPF of at least 30 and pay particular attention to the back of your neck which is especially exposed on the bike. Don’t neglect your head as it is very easy to get burnt through the vents on your helmet. Look for sunblock with lasting protection and be sure to follow the instructions of when to apply them. With heavy sweating though, even the best sunblock won’t protect you over the course of a long day in the saddle. Carry a small spray bottle in your jersey pockets or saddlebag and re-apply every hour or so.

Look after your eyes

Sunglasses not only protect your eyes from damaging UV rays but also prevent dust, grit and flying insects from getting into your eyes.

Insects can be a real problem as the vents on modern helmets suck them towards your head and face. Carrying some non-drowsy anti-histamine tablets or some topical cream can significantly reduce the impact of an insect sting or bite. If you know you are allergic to insect stings, make sure that you are carrying the appropriate medicine, you have the necessary personal medical information on you and that you have informed your riding partners.

Check the pollen forecast

In rural areas, high pollen counts can be an issue for riders who suffer from hay fever and again, weather forecasts should be consulted and, if necessary, riding plans altered. In urban areas hot weather can lead to a significant reduction in air quality. Most weather forecasts now also carry air quality and pollution level warnings. Riders with asthma and other respiratory conditions need to be especially vigilant and should always carry their inhalers or other medicines.

Cool down post ride

Always aim to spin easily for the last ten minutes of any ride and then, along with your regular post ride recovery routine, make cooling your body a priority. Get out of the sun, blend some ice into your recovery drink and take a cool bath or shower. Keep sipping fluids, ideally containing electrolytes, for a couple of hours after your ride and don’t forget the aftersun.

Spotting heat exhaustion and heat stroke

By following these tips, you should have a problem free summer of cycling but, with gruelling events pushing riders close to their limits, being aware of heat exhaustion and heat stroke and knowing the warning signs, is vital knowledge for all cyclists.

Heat exhaustion results from a decrease in blood pressure and blood volume. This is due to the loss of fluids and electrolytes when exposed to the heat for a prolonged period of time. As well as general fatigue, symptoms include, feeling sick, faint and heavy sweating. The skin will be flushed and hot to the touch, heart rate elevated and the rider may also complain of feeling dizzy and appear confused.

Any rider displaying these symptoms should stop cycling immediately and find somewhere cool out of the sun. They should be given fluids to sip, ideally water or a sports drink, and may be cooled with a wet flannel or light spraying with cool but not cold water. They should recover within 30 minutes but, if they are still displaying symptoms after this time, contact the emergency services.

If the symptoms of heat exhaustion are ignored and the rider continues to push themselves, exertional heat stroke, where the body temperature rises to dangerous levels, can occur. Heavy sweating will stop, the riders skin will feel cold and clammy and they may complain of feeling cold despite the heat. Heart rate and breathing will be significantly increased and they may also be suffering from muscle cramps. They may vomit, complain of having a headache and be confused and disorientated. In severe cases, fitting and a loss of consciousness may occur.

The priorities are to get the rider out of the sun and to contact the emergency services. While waiting for them to arrive, if conscious, the rider should be given fluids to sip and can also be cooled with a damp flannel or spraying. Avoid complete immersion in cool water and do not give any form of medication.


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