It seems to be a simple question, but the answer is complicated. Heat is a complex problem and it should be approached from several angles.
When you’re training and preparing for the race you must consider the weather conditions during the race you are preparing for, your mental, psychological and physiological conditions, your technique, your food and drink, your outfit, shoes, your time of training and your training load
Heat could be complicated by dry or humid air. If you live in a place where heat is normal, such as Arizona, South Florida, or Texas and you are supposed to race there, it is one story. But if you live somewhere with much lower temperature and have to race in the heat, then it is another story. So there are lots of questions and lots of ground to cover. I would like to share with you, my approach, my logic on this subject and your job will be to take your training plan with all its numbers and structure it accordingly.
DEFINING THE GOAL
Where do we start? This is a big topic and cannot be covered in one article, but at least we can layout the foundation for better understanding and further discussions. We need to put some benchmarks, define the field of our interest and determine the major components of the training system. This should not be about one event, one race, and for a limited time, but instead, it should be about introducing some elements into your training that will elevate your performance in general and help overcome the hot weather ‘hurdle’ during the upcoming race.
So, your training plan for the race that’s coming up should be of a bit longer duration and include a month or more of living in such climate and training there as well. The final goal of this training is to adapt your mind and body to constant heat condition and develop your ability to produce high quality of training and racing performance.
OK, first things first, it is about our mindset, attitude or how you perceive the heat.
- Is it a dangerous thing or something you can deal with?
- If you can deal with it, then the question is how?
Fear could be the first and the main obstacle to overcome. Your mind could perceive things as so dangerous, that your physiology would fail even before the heat hits you. It would appear as your predisposed reactions to danger.
- You could become very concerned
- run with many precautions
- overestimate the weather conditions and underestimate your own condition
- your heart rate may go high and your running pace could seem too difficult, and your desire to drink to keep you from dehydration could dominate over everything else
So what are you supposed to do? First thing is to calm down and understand that it is up to you how long you can stay and train under this condition. You don’t need to kill yourself at the first training session or any sessions after that. So this is the test training of what you can handle from the beginning to the end. After that, each training session is a research and a discovery of yourself as to what your strength is and where your limits are. Following your plan is a good thing, but in such cases, it’s better to first find out what you are capable of and then correct and adjust your plans accordingly.
The simplest question is how to define the time of training. Most long distance races take place in the morning, so your training should happen at this time, as well. It doesn’t mean that the weather would be comfortable at that time, but at least a little less heat. Only some of the triathlon races, such as Ironman Hawaii happen in severe heat weather conditions and therefore training for them requires the same weather condition, as well. The time of your training should coincide with the time of your future race. To which extent is the question of your adaptation abilities.
The next thing to consider is your training load. It is closely connected to your psychological and emotional state. You have to define for yourself, how long could be your training distance in the heat condition, which you can run without having panic attacks that after this mark each step could be your last one. I call it the method of training under the fear level. It should be clear that once fear is settling in your mind, there is no adaptation of your body’s systems anymore. You cannot adapt to fear. You could accept it, but not adapt to it. Fearful reactions are for your protection and defense, but not for your development. But before we even reach this level, our running technique will deteriorate and we need to know the signs of deterioration, recognize them on time and make corrections if it’s still possible or stop training if corrections are impossible. The technique is very vulnerable to heat because of an impact on our mind and physiological systems.
BODY TEMPERATURE LIMIT
One of the most vital components of a successful training in the heat is an ability to sustain the temperature of the body at a level allowing its efficient functioning. Professor T.Noakes in his book “Lore of Running”(1) wrote: “To live, we humans must keep our body temperatures within a narrow range (35 to 42 C) despite wide variations in environmental temperatures and differences in levels of physical activity. However, during exercise, the conversion of chemical energy stored in adenosine triphosphate (ATP) into the mechanical energy that permits exercise is extremely inefficient; as much as 70 percent of the total chemical energy used during muscular contraction is released as heat rather than as athletic endeavor. It is clear that in order to control the heat rise associated with exercise and so doing prevent overheating and heatstroke, the body must be able to call upon a number of very effective heat-diffusing mechanisms. ”
It is well known that exercise increases muscle work, which increases blood flow and heat of the body by bringing heated blood to the organs and to the skin. After that blood flow distributes heat over the body and to the skin where “circulating air currents then carry this heat away by convection. (Convection is simply the transfer of the heat energy into the surrounding air.)”(1). The body’s heat is lost when the temperature of surrounding air is lower, and by this difference, it’s attracting the heat. On the opposite, when the temperature of the air is higher, then the body is attracting the heat from surrounding air. As we know, at rest, the body skin temperature is about 33C. This fact clearly indicates that heat can’t be lost if the surrounding air temperature is greater than 33C, and this fact should be a warning signal for a runner to make adjustments for his training.
During an exercise, the athlete’s body accumulates heat until the body temperature gets to the critical level when heatstroke can occur. This “terminal” temperature is about 41C and the body’s sensors send a signal to the brain, which shuts down physical activity in order to prevent heatstroke. This preventive mechanism in some cases, as it is mentioned by Dr.Noakes (1), is overrun by a strong will of the runner, which leads to heatstroke.
One of the efficient mechanisms of reducing the heat of the body is sweating, but “it is important to appreciate that sweating itself does not cause heat loss: it is evaporation of the sweat into the atmosphere that causes heat to be lost”(1). Otherwise, we are just losing water, but not the heat, and this is another problem.
Another important parameter of the body heat development is the air humidity. With increasing air humidity the body’s ability to lose heat by sweating is decreasing. It happens because humid air can’t absorb additional water (1). This factor is making the heat problem even more complex and should be on a priority list in training planning.
ACCLIMATISATION & TRAINING
Acclimatization to heat takes about 7 to 14 days according to Armstrong and Maresh (2). Scientists’ opinion is that training should be done in the heat for gradually increasing periods of between 30 to 100 minutes for an initial period of 10 to 14 days (3). Dr.Noakes (1) thinks that full heat acclimatization is always superior in those who have always lived in hot environments, and here again we return to what I mentioned above – when you’re psychologically accustomed to specific conditions no matter how different from what is considered the norm, your reaction to such conditions is very different from someone newly introduced to these conditions. So give yourself some time to settle in order to improve your outcome. Nielsen (4) considers that daily experience to rising body temperature and prolonged exercise induces adaptation. The adaptation to heat is lost in approximately about 28 days.
The important changes that occur with heat acclimatization are that the heart rate, body temperature, and sweat salt (sodium chloride) content during exercise decrease (1,2,4). This data could be used to identify the adaptation of the body to the heat, as well as your ability to run faster and longer based on the level of your adaptation. Another indication of improved ability to train in the heat is the rate of perceived exertion (RPE) or your perception of the difficulty of training, which together with other data could be good indicators of the training progress in the heat.