Yesterday I rode 45 or so miles. The temps when I left were 95 degrees. The temp when I got back was 109. I could tell when I got back that I was right on the edge. I actually cut my route short a bit because I had run through my water much faster than anticipated. The Queen questioned the wisdom of me training under such conditions. Given that I did not have a heat injury, I feel it was a successful session. However, like I said, I was right on the edge. If I did have a heat injury, it could have been a bad day.
These thoughts prompted me to do some cursory research on training in the heat. A few days ago, I read an article about a Navy Lieutenant training for an ultramarathon while on ship. One of the things she would do is actually train in the sauna. She is an experienced ultramarathoner, so my assumption is she knows what she is doing. As it turns out, she does.
Training in the heat can provide some significant advantages. However, there are two extremely important preconditions. First, you must train smart. Second, you must already be fit.
Training smart begins with being meticulous with your hydration, pre-training, during training, and post-training. Being fit before the hot season is also key.
Be fit beforehand. Studies show that athletes who are fit prior to heat training show marked improvements over those who are not. Additionally, the type of training you did in the cooler conditions also matters. Intense, interval type sessions conducted in cooler weather translate to faster heat acclimatization over moderate, low intensity sessions.
Listen to your body. If a session in the heat really sucks, cut it off. It is better to cut a session short, and be able to train tomorrow, than risk a heat injury. Heat injury could mean missing several training days, or it could mean having a dangerous, even life-threatening incident on the road somewhere. Even in the gym, heat illness can become a critical situation.
To become acclimatized gradually increase training durations, as tolerated. Maintain lower intensities and volumes. End a session if it becomes too hard. Stay hydrated throughout.
Given these pre-conditions, acclimatization can occur within four to eight days.
Once acclimatized, heat training intensities and volumes should be maintained lower than the same training in cooler conditions.
Heat training sessions pay off in two ways. Acclimatization and subsequent sessions allow you to perform and compete better in hot conditions. Also, once the weather cools off, the work can translate to improved overall performance.
Training in the heat is a risky type of training. Like other forms of high intensity protocols, it requires one be diligent about safety, proper recovery, planning, and moderation. However, there are some significant benefits to be had. Additionally, the Summer is a third of the race season, thus properly preparing to train and compete in it is a virtual necessity.