From a standpoint of evolution, we are selected more for endurance compared to anything else. More than power. More than strength. More than speed.
Since the beginning of it all — the hunting and gathering days — some 2 million years ago, a typical person would have walked or run about 9 miles per day. That number would have been much higher on “hunting time” days.
Granted, we are not the hunter/gatherers that we were back in the day and our lifestyles are dramatically different. Nevertheless, it is still engrained within our DNA and our system. Universities such as Duke estimate that humans are capable of covering over 300 miles at one shot. We have seen consistently amazing feats such as runs by Dean Karnazes and Scott Jurek and others that include running across deserts, 50 marathons in 50 days in 50 states, 100, 200 and 300 mile runs and more.
For many of us, time is an issue and we are willing to train for a marathon but not a 200 mile event. Others are not willing to go even the magical 26.2 miles. Willingness and ability to do so, are 2 separate issues. The truth remains that we are designed for the distance.
Doc’s Thoughts: Take a risk and run a marathon. Start with a 5 or 10K and work your way up. If you do it correctly (correct form, fitted shoes and nutrition), you will not only be fine, but you will be a different person at the finish. It is tough. It is very difficult at times but at the end, the gifts that you will receive will far outweigh the temporary soreness or stiffness. Take a risk. Be something other than common!