Don't know but maybe this will help some of my fellow really new riders with the issue of getting the lungs to open up. In spin classes, we did a good long warm up (my trainer, who just won the PA Master's Championship & is going for the Nationals in IN, is VERRRY serious about warm up, cool down, and stretching) but when I started road riding - I'm facing a hill of some sort almost right away no matter which way I turn out of the driveway. (I ride in eastern PA, any flat land was shipped to the midwest centuries ago). The suggestion was made that before I get on the bike, I go for a short brisk walk to open the lungs and warm the legs. That has really helped, especially in cooler weather.

To the good, as frustrated as I can get with my progress sometimes, today a woman my age thought I was ten years younger than she. I guess I gotta get her on a bike