I received a good lesson in mindfulness a few weeks ago when I tweaked my lower back while lacing up my gym shoes. I knew that staying active would aid in recovery, but that the wrong type of activity could make things worse. I listened closely to what my body told me, employing a sort of stoplight approach: green (“Feels good…proceed!”), yellow (“Can you modify this a bit?”) and red (“Don’t even think about it!”). 
Walking was a green light. Yoga (as I do it) was mostly green with a touch of yellow. Weight lifting was a mix of all three, so I really had to practice being mindful. This went on for a week-plus before I could resume my normal fitness routine (although I’m keeping a few back-friendly modifications as a preventive measure).
I had maybe two good days of normalcy before I got slammed with a sore throat. I knew it was the precursor to a cold…my first in two years. My body was sending me a clear message: “Rest!” So I did, and ingested copious amounts of hot tea and chicken soup for good measure. I managed to arrest my cold symptoms before I hit the runny nose phase, but I could feel my energy level shift dramatically for several days. On the good days, I did a little yoga. On the low days, I shut down my computer early and took to the couch with a blanket and a book.
When you ignore your body, an otherwise healthy choice can become unhealthy. If I had chosen to push myself to stick to my normal physical activity habits, I may have prolonged my back pain and ended up making short work of a Costco-size pack of tissues.
It’s easier to stay in tune with your body and what it needs from day to day when your choices are guided by health and well-being rather than a number on a scale or inches on a tape measure. I used to get colds more often than I do now (about every six months) and would freak out if I couldn’t hit the gym every day. Along similar lines, I would often favor activities that “promised” a huge calorie burn, instead of focusing on activities I enjoyed. I would also force myself to eat “healthy” foods that I didn’t enjoy, instead of basing my meals on nutritious foods that suit my palate. I don’t make those mistakes anymore.
Whereas a lot of my choices used to be weight-focused, now they are driven by desire to enjoy good health each and every day for as long as possible. I feel my best when go for a walk at least six days a week, eat a lot of vegetables and keep portions of rich foods small. Some days, I love exercise for the physical sensation of moving, on other days it’s primarily a way to clear my head when I’ve broken my brain from hours spent writing and researching. Sometimes, it’s a much-needed release after a stressful day! 
When we make healthy choices that resonate with our body and mind, instead of simply doing what we’re “supposed” to do, we’re happier, we feel better and we’re more likely to keep on making healthy choices. That’s the sustainable road to optimal health.