|River City Ramble 1/2 Marathon, 2011|
Heat, however, is a different story. There are only so many layers one can shed before law enforcement gets involved.
That said, running in the heat, when done intelligently, is phenomenal for training adaptations. Research has shown heat training leads to similar gains than training at altitude.
Read this nice article from Runner's World, "Heat Stress, Plasma Volume, and the Benefits of Dehydration" for a detailed look at how to train in the heat.