Since I started riding Graham (my Rivendell Sam Hillborne), a few readers have commented that I have nicely defined legs in my pictures. I generally don't do well with compliments, but I think this particular one is worth addressing - because I have my bicycle to thank for it.
The legs are quite "new" and seem to be a direct result of riding a roadbike. Having ridden upright bicycles since Spring last year, I experienced a general increase in my level of fitness and some definition in the calf muscles, but nothing like this. Before the roadbike, the area above the knees was ...shall we say, cottage-cheeselike. Now it's long, lean muscles, and I still can't quite believe that they are mine.
The change began to happen almost immediately when I started to ride in a leaned over posture, and even in the process of cycling, I can feel the difference between this kind of cycling vs riding an upright bike: When I am leaned over, it feels as if I am pushing with the back of my thighs; when I am upright, it feels as if I am pushing with my calves. When going uphill, the strain increases, but it always remains within the bike-specific muscle group. That is, I never feel as if I am pushing with the back of my thighs on one of my loop-frame bicycles, even when going up the steepest hills.
I have the bad habit of forming theories too soon about things I do not entirely understand, so I asked an acquaintance - bicycle fit expert Kevin Saunders - whether what I felt happening is real or imagined.
Kevin's explanation was that the glutes (butt muscles) and quadriceps (thigh muscles) need the cyclist to be bent over for them to engage, so it makes sense that this should happen when cycling in a leaned over posture. Furthermore, if you are pushing down hard enough on the pedals, you are holding up your torso with your core and back muscles, which act as a resistance to the load generated by the glutes and quads. Essentially, this means that the muscles in your abdomen and back will get strengthened as well - resulting in a flat tummy and a decrease in "muffinage" - both of which I have noticed as well.
Don't worry, readers: This is not a fitness website and I do not intend to start regaling you with the details of getting in shape. But I do get questions from women about fitness, and I think that may be because they feel more comfortable asking me (a self-admitted "unathletic girl") than someone who was more sporty to begin with. Getting in shape was never my goal, but I admit it is a nice side-effect. The bicycle is a talented sculptor!