Exercising is indeed a physical endeavor, however the mind plays a much more important role than many realize. Our bodies are not as fragile as we believe, yet once we have an idea of how many reps or how far we can run, it seems our bodies give out at that time. Give yourself a chance to push your limits and your body will respond.
I recently went for a run after years, and I was never an avid runner to begin with. There were inclines and declines and it was a hard surface. I ran ½ of a mile in around 5 minutes, which for me was something I really had not done when I weighed 175 lbs. I recently lost weight, going from 282 lbs. in February to now weighing 225 lbs.
After a short distance my mind said I was ready to stop because my body felt tired, yet I convinced myself to continue until I went around and met up with my family who was walking on the same trail. After I decided that I was not going to stop until I reached that goal, my body did not feel quite so tired and I made my goal. It is the same thing in the gym.
When we decide that we are going to do a certain number of reps, it seems we are always exhausted or at least done with the exercise when we hit that number. For me there are times where I know I could have kept going, but because I reached the number I decided on, I quit. The issue is that the only way to reach new levels is to push the ones you already are on. And the way to do that is mainly through the mind.
The body will never convince the mind that it can do more, but the mind can surely convince the body that it is capable of doing more. This is important to remember when confronted by negativity from others. The surest way to fail is to leave yourself open to negativity. Once you have it in your mind that something cannot be done, it will not be done. And remember that most people that will tell you that you cannot do something are those that failed, or have not tried at all. Instead, speak to those who have tried and succeeded. Once you see one person can do it, you will know it is possible. And if you have the right attitude you will only require that something be possible, not that it be easy. Results speak far louder than words.