Let's revisit my recent 100-mile race - not because I believe it's so fascinating, or because I think you should strive to run ultra marathons (no one should, except for the truly insane....). Let's revisit it because there are a couple of good lessons that apply to everyone, no matter what your fitness level or goals.
First lesson: Run your own race. This is always true in a long race. You might be able to "race" someone in a shorter race, but when you're out there for 20-30 hours, the only thing that's really sustainable is your pace. Last weekend, with my cold, I had to focus even more on that. I had to go at a comfortable pace that my lungs could handle. That meant ignoring people passing me. That meant not paying attention to my GPS and worrying about my pace. That also meant not getting into many conversations while running because then I would be tempted to keep up with other runners to continue the conversation.
What does this mean for you? Your workout, your fitness plan is yours - no one else's. The amount of weight you lift, the number of reps, the distance, the amount of time, the speed are all about you, your current level of fitness, and any restrictions you may have. What the guy next to you at the gym does has nothing to do with you. What your neighbor does has nothing to do with you. What some magazine article about body builders says has nothing to do with you (unless you are a body builder). Run your own race.
Second lesson: Pay attention to your body. Listen to the cues your body is giving you. Our bodies are constantly changing - we get more or less sleep, feel stress, get colds.... Don't just put on some headphones and zone out. Don't just blindly go with a plan of a certain number of exercises or speed. Pay attention to your body and make adjustments as necessary.
Third lesson: Stay present. People constantly ask me what I think about when I'm running for 30-40 or more miles. Yes, I think about things, but a whole lot of the time I'm just focused on right now: how am I feeling, what's that pain in my ankle, watch that root, how's my heart rate, drink.... I am constantly monitoring how my body is reacting and performing. I do the same thing when I'm doing strength work. I want to be sure I'm challenging myself, but want to do it safely.
Staying present is a great tool for your body and your mind. It can help you avoid injury and is a great exercise in learning to focus on the things you can control right now and letting go of all the other stuff. Stay present.
All three of these are obviously related. They're really just aspects of the same thing - working out (and living) mindfully.