Environmental Stress. What does that even mean?
Well, it means in order for you to get fully fit in the most efficient way possible you must consider the fact that things like heat and A/C are unnatural and constantly training in conditions with optimal temperatures might be slowing your fitness journey down unnecessarily. Also consider the fact that when fighters/boxers are training to get in shape and into fighting form in a hurry they train in extremely high temperatures to help themselves do so. This also helps their conditioning as well. There has also been the recent health trend of cryotherapy where athletes will spend time in extreme freezing temperatures in a closed chamber in order to help rejuvenate their bodies to help maximize their own performance results.
Now, the point is not that you need to go to one extreme or the other but doing something like running outside on a hot summer day can help push the average person to their limit which is exactly the result we’re looking for. Consider this concept similar to the concept of eating natural and fresh food versus eating processed foods – we all know which one is good for us and which one isn’t right? The natural option. The same goes for your environment training and living in natural surroundings is better for you than doing so in an environment with mostly artificial elements such as temperature.
In the end, consider anything artificial: foods, temperature etc as a comfort option – it’s nice when you are relaxing and/or on vacation. However, when you are on your normally daily grind you should always try and opt for the natural choice – it’s better for you!