Heat Training

Summer is here and it is heating up. Should we train earlier in the morning or later in the evening to avoid the hot and humid environment? What many people do not realise is that there are physiological adaptations that take place in heat and humidity and these can also be performance enhancing. Those who train through the heat of January and February will have an advantage going into the cooler racing months of March and April.

Rather than trying to avoid the heat and humidity by running early, late, or shedding clothes you can enhance these adaptations by doing "heat training". Wearing tracksuit pants or an extra layer during summer will improve your heat tolerance. I have seen many elite African runners training in full track suits in the middle of a summers day. They don’t seem to worry when conditions are hot and humid in major marathon races.

A 2010 University of Oregon study confirmed that heat training was just as performance enhancing as high altitude training. The study took highly trained cyclists and after a 10-day heat training programme found a 6% average increase in performance. If applied to a 3-hour marathon it would result in an improvement of 11 minutes. The study recorded a 7% increase in blood plasma, a 9% increase in maximal cardiac output and a 7% lower lactate level. Increasing the blood plasma level and the heart’s stroke volume helped to more effectively remove blood lactate.

The study also recorded an average 5% increase in VO2 max and when subjected to post heat training exercise the subjects only needed to work at 85% of their previous capacity to do the same work. VO2 max is a figure that refers to the maximum amount of oxygen that an individual utilizes during intense exercise. It is measured as millilitres of oxygen used in one minute per kilogram of body weight. In theory, the more oxygen you can use during high-level exercise, the more ATP (energy) you can produce. Elite endurance athletes typically have very high VO2 max values. While VO2 is largely determined by genes, it can be increased by training but there is a proportion of the population for whom training seems to make little difference.

Even if we disregard VO2 max figures, heat training helped to more effectively utilise oxygen, increased overall blood volume and better controlled body temperature by increasing sweat rate, and a greater blood flow to the skin. However, if trying this type of training do not overlook a crucial element. You will need to replace the minerals, electrolytes, and water lost in your sweat! There are supplementary drinks that you can purchase but citrus fruits and eating sodium, magnesium and calcium rich foods are also important. Hydrate extra well with a variety of fluids and become familiar with your typical body weight (before and after runs). One recommendation is that after training go home with track suit pants on. Even this little tip helps by keeping the tired leg muscles heated and therefore more effectively clears the blood of exercise lactate. It is sometimes the little 1% things that by themselves do not make a great improvement to your performance. But by routinely doing several 1% activities in your daily life they will add to help you enhance your performance.