The great thing about running a big race in the early Spring is that it forces you pursue a training cycle through the Winter months. That's all well and good when you live in warmer climates and can do the majority of your runs on the same surface upon which your race will take place. Living in Lower Michigan, I have a 'real' Winter with snow, ice and bitter cold winds. For me that precludes a lot of outdoor running opportunities.
Enter the treadmill. I am fortunate to have access to a treadmill so that I can keep my training on track, but using it presents a big challenge. It's the challenge of 'will power', 'mind over matter', 'pushing yourself to the limit' and other idioms that speak to crossing over some mental barrier.
Recently, my training schedule called for my weekly LSD (Long-Slow-Distance) run. This particular one was for 12 miles. After running for almost 5 years and training for many distance races, a 12 mile run does not cause me worry. I know well that I have the stamina and strength to complete this type of run as I have done it many times before. What gives me pause is completing such a run indoors on a stationary machine with no changes in sights, sounds, smells or anything. The only thing that changes are the numbers on the machine as they count up the miles and time.
What this takes is mental stamina. The will and resolve to get it done. Sure you can stop any time, and the walk to your car is the same as when you started. There is no incentive to complete the run based on the need to get back to your starting point as you have when you are way out on an outdoor run. All you have is internal drive to complete what you choose to do.
So my recent 12 mile run on a treadmill was a PR (Personal Record) for the longest run on that machine. It was extremely challenging and I consider it an important accomplishment and worthy to be added to my list of mental mountains that I've beat. Oh, and it was hard physically as well.
Developing and maintaining any good habit that is difficult, such as a fitness routine, requires a decision of it's importance, prioritization, and resolve to see it through. These attributes are also continually tested and developed throughout the ongoing nature of the task. So while you may have passed a milestone as simple as starting your fitness program, you will encounter two forms of resistance, external and internal. The only one you have control of is the internal one, but you can use your mental resolve and willpower to be successful.
Go do it!