Posted on April 01 2018

Dehydration is normally the product of your metabolic rate (go harder and you sweat more). But add the significant thermal stress from the sun exacerbating the sweating process, and you’re obviously going to lose bodily fluids at an accelerated rate.

So what should you do when cycling in hot weather?

1. Drink enough liquids.

Correct hydration before, during and after training, plus appropriate clothing options are essential in beating the heat. 

Many people underestimate their fluid intake needs and wonder why they fail to enjoy their summer riding. In a worst case scenario, they may even become unstuck in races or rides that they’ve achieved before.

Periods of hot weather catch many riders out, and many medical experts attending endurance events have reported a growth in people failing to pre-hydrate. Most people take little liquids with them or just drink water, rather than a fluid-replacement drink.

2. Do your best to prevent sunburn.

Radiation from the sun is another factor that catches many people out. A dab of suncream does not give you a permanent shield against the sun. 

In most cases you have a two-hour barrier — you’ll need to reapply if you’re riding in the sun for any longer than this.

3. Train in the heat.

You can drink smart and dress right, but you still need to train to be better in the heat. 

One advantage of training in the heat is that your body becomes more efficient at sweating and makes appropriate hormonal tweaks to ensure the next time you exercise, your body will retain liquids better.

Here are three top training tips for improving your fitness and resilience in the heat.

Ride in peak temperatures.

Do a weekly midday ride, or as near to peak daytime temperatures as you can get. 

If it's not hot enough on your training days, add thermal stress by riding in extra layers. You’ll definitely need to up your liquid consumption, and be wary of excessive heat stress. 

Although you will feel uncomfortable, it’s a worthy session to include. Riding in a sauna is not unknown but that’s an extreme measure for an extreme goal. Riding in the sun will be perfectly adequate for acclimatising most folk.

Get fitter & leaner.

You need to think fitness as well as equipment when planning to ride in a hot race, such as the L’Etape or the Gran Fondo. Fitter and leaner riders tend to deal with heat better.

One reason is that fat tends to insulate a person. So, if a rider with a higher percentage of fat is riding uphill in the midday sun, it’s a lot like trying to ride with a duvet on. Meanwhile, the leaner rider gets rid of excess heat faster. They will also generally climb hills for less time because they have a better power-to-weight ratio.

4. Know your limits.

You need to know what your drinking, heat and endurance limits are. By stretching yourself, experimenting with different drinking strategies and going into the unknown, you’ll find out if you’re a warm-day wonder or a cold-conditions cyclist. 

When thinking about your rides, don’t just think about fitness gains but also the environmental conditioning you’re getting accustomed to. Test your limits and choose how you approach them depending on your strengths and weaknesses.


1. If you have limited chances to drink (in a 50-mile TT, for example) and it’s very hot, glycerol hyperhydration can enable approximately 750ml more liquid to be available for sweating over a four-hour period.

2. Stay in the shade and drink plenty of cool liquids if you stop mid-ride — definitely no sunbathing or alcohol! Booze is a bad move and make you more prone to falling off.

3. Drink throughout training rides and racing using 5–8 percent fluid-replacement drinks and high-energy glucose polymers (minus 10 percent concentration). The rough guide is 500–800ml per hour, but experiment in training to know how much works for you (a hint: it’s not 200ml per hour of plain water and nothing else!).

4. If you’re racing early in the day, an aero helmet may save a few seconds. But if it’s going to be a long hot day go for a vented helmet.

5. Your clothing colour is a critical choice. Some black colour schemes absorb rather than reflect heat, so go for white and pale colours.


1. Inner and tube levers — don't forget these obvious essentials.

2. Extra money for water, ice cream or hi-carb snack food.

3. A pot or bag of energy powder or a couple of gels. These are hard to find at a service station or shops.

4. Small sunscreen pouch, with an SPF of at least 20. Forget SPF4 or SPF6.

5. Mobile phone.


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