It’s that time of year where we are all riding and racing in the soaring temperatures. Our resident coach, BEN CAPOSTAGNO gives some tips on how to better prepare for a hot day out.
Summer has arrived in the southern hemisphere and the environmental temperatures are high. Despite the early start times of many races, cyclists are still exposed to some very hot ambient conditions during races and endurance performance can be significantly impaired under high temperatures. .
When we train or race in the heat, we redistribute our blood flow to our skin and increase our sweat rates.
These two responses help us to reduce the physiological strain experienced by the increased temperatures. We also reduce our intensity in hot conditions, in order to prevent us from ‘over-heating’. It is possible to reduce the effect heat will have on cycling performance by acclimatising prior to competition.
Regular exercise in temperate conditions will result in partial heat acclimation, but a deliberate heat acclimatisation protocol will yield greater benefits. Heat acclimatisation will improve the level of comfort in the heat as well as maximal and submaximal performance in hot conditions. The improved performance is mostly due to:
- Increased sweating response
- Improved skin blood flow response
- Increase blood volume due to increase in plasma volume
- Improved fluid-electrolyte balance.
HOW LONG DO I NEED TO BECOME HEAT ACCLIMATED?
The majority of the physiological adaptations develop within the first week of a heat acclimatisation protocol, but continue in the subsequent two weeks. Well-trained cyclists will adapt faster than their lesser-trained counterparts, so consider your training status when planning the length of the protocol. A minimum of two weeks is required to completely acclimatise to hot ambient conditions.
SHOULD I COMPLETE ALL MY TRAINING SESSIONS IN THE HEAT?
Training in the heat will result in a reduced exercise intensity due to the increased thermal strain. It is
important to remember this, so the overall training load can be planned appropriately. The initial training
sessions in the heat can be relatively short (~ 1 hour) and performed at a low intensity (~Zone 2). As you
become acclimated to the heat, you can start to include one high-intensity session per week in the heat but
avoid performing all your training in the heat, so the training stimulus is not reduced.
WHAT KIND OF ENVIRONMENTAL CONDITIONS ARE BEST TO BECOME HEAT ACCLIMATED?
The best environment to train in will be one that is similar to the competition environment. Heat can
be dry, or it can be accompanied by high levels of humidity, so it is best to try and match the training
environment to the competition one. If the weather is not playing ball, it is possible to create an artificial hot environment with the use of heaters and air conditioners. However, training in natural heat is still closer to competition environments and should be preferred to artificial heat.
HOW LONG DOES THE HEAT ACCLIMATIZATION LAST?
The bad news is that heat adaptations are not permanent. However, the good news is cyclists lose them at a slower rate than they gain them and most of the adaptations last for between two to four weeks. In addition, re-acclimatisation during this period occurs at a faster rate than the initial process.
In summary, the following recommendations can assist cyclists in becoming heat acclimatised:
- Cyclists planning on competing in hot environments should include a heat acclimatisation protocol as part of their training in order to promote physiological adaptations that reduce the effect of the heat on endurance performance.
- Training sessions performed in the heat should increase the body’s core and skin temperatures, as well as stimulate sweating. Sessions of one hour in duration and at a low intensity initially will be sufficient to promote adaptations.
- The training environment should mimic the competition environment as closely as possible. Temperatures and humidity should be matched, but artificial environments (indoors) can also be effective.
- Adaptations start early (first few days), but a heat acclimatisation protocol should last two weeks in order to ensure full benefits.