EDIT: Looks like that Tacx trainer has a built in PM, so disregard what I said about inaccurate data.
Also, you yourself admitted you've done almost no exercise for 15 years and just started riding indoors 3 weeks ago with a single outdoor ride. You will need a LOT more time riding before you should worry about comparing yourself to other riders. Don't let it discourage you, it's such a great form of exercise and a great way to explore your area, and you apparently jumped right in and got a great bike.
Last edited by Dan333SP; 04-19-16 at 10:33 AM.