Yesterday was a challenging day for me. I set the bar high for myself with a 3 mile hill repeat run followed by a 90 minute hot yoga class. Twice I found myself right on the edge. I felt like I had no more to give, and slightly sick, but I pulled something from somewhere and finished the workouts. By the end of the yoga class I was limping in, but I finished, and I felt so accomplished it's not even funny.
I tend to push myself in my workouts, I really enjoy pushing above and beyond what I've previously been capable of, even if I try and fail miserably. This characteristic is what runners call mental grit. You can't measure it, you can't tell who has it by looking at them, it's that small voice deep down that silences all the negative speak that we're so good at using on ourselves. It's the part of you that pushes through when you wanted to give up three miles ago.
Now, there is a difference between pushing yourself, and pushing yourself too hard. Nausea is not something that I strive for, and I've actually rarely felt that before (I think part of it had to do with the heat element involved in last night's endeavors). I wouldn't recommend anyone push themselves that hard consistently, it's hard on the body. What I would recommend is that everyone take one or two workouts a week and push themselves just a little harder, just a little longer than they think they can go. Sometimes that's all you need to see some changes. Practice your mental grit.