On a road bike
Consideration 2: Comfort vs speed.
The reason why athletic abilities come into the picture is because the riding posture on these bikes can be very different. On a road bike, speed is the key concern. So everything is about being aerodynamic. Hence, there are drop handlebars. The handlebars require the rider to arch the back forward to achieve a more aero position. If you've never ridden a road bike before, this position can be quite uncomfortable. But most people get used to it after a while. Initially, you may experience some pains in the neck and back. Once you get used to riding a roadie, you will start to enjoy your rides more.
But if speed is not your number 1 priority, then a mountain bike would be a better choice. The handlebars are flat, which enables the rider to ride in an upright posture. You wouldn't be able to catch a road bike on that posture. But that's not important. It's more important that you are comfortable on the bike.
