2015 Tour de France Highlights and Analysis Stage 11

Dealing with the Heat: how to race in hot climates

Given the heat experienced during today’s stage, I thoiught taking a look at strategies to improve performance in hot climates was appropriate. A lot of it is common sense, or at least makes sense, and the trick is having a strategy to apply on days such as these.

 

 

Pre-Cooling

Today’s stage was getting close to 36 degrees C in parts and averaged 29 Celcius, so a valid tactic is to pre-cool. This is likely more useful in short hard efforts such as TTs. In the Stage 1 TT Nibali was seen wearing a cooling vest during his warm up. This works by keeping the core temperature from rising too much while warming up and therefore keeping it lower during the TT (since his core started from a lower temperature).

In a study reviewing pre-cooling studies, Wegman et al 2012 found that pre-cooling works better the hotter it is and the most effective methods (in order) are: cold drinks (15%), cool room (10.7%), packs (5.6%), vests (4.8%) and water application (1.2%). The effect is greater in fitter individuals (read that higher VO2max). Putting this into useful numbers, on average endurance athletes improved performance by 3.7% when pre-cooled for a TT.

 

Cooling on the Bike

If we look at the above methods, some of them can be applied while riding:

While we are mentioning this last, probably the first thing to look at when racing in the heat is adequate hydration. We reviewed this in our recovery series, but some points to consider are:

• During the workout you can generally absorb about 1g of carbohydrate per kilo of body weight. There is some recent research (by Jeukendrup) that suggests this figure can be improved with different combinations (glucose/fructose, caffeine/carbohydrate, maltodextrin/fructose etc).
• Consider a sports drink with a 1:4 ratio of protein to carbohydrate. Research suggests that it increases glcogen synthesis, decrease muscle damage and aids recovery. It may also help endurance during your ride, but this is inconclusive.
• Aim to consume between 500-800ml/hr of a 6-8% carbohydrate drink, depending on heat and sweat loss (up to a litre in extreme conditions). This will mean that you will need to consume about 20-40g of carbohydrate an hour to make up to 1g/kg/hr.
• Drinks should contain between 0.3-0.7g/L of sodium also.
• It is also important to test and trial any food in training that you are planning to use in races. Palatability is also an important consideration.