great job---i also got an old bike out and started ridingfor cardio @ 6 weeks ago.....not far or fast too...but my weight right now is too heavy for my alkes and feet...i love my biking---i try to do 30 minutes after dinner each night...i find hills the i never knew existed--really they r inclines that feel like small mountains...i have been able to build up my endurance and add musclee to my legs and butt without injuring myself...i now can go @ 25 miles on a good day--my bike has no gears or fancy stuff...sometimes to brn more il doo intermitant perods of going as fast as i can---usuall up an incline for about 1 minute.. builds me up faster..no ambition for a better bike or biker shorts or riding with groups..i usually just put on my heaset w some crosby, stills and nash and the time flies...i w will say get a good bike seat it makes all the difference in the world---tmart.com have some rasonably priced--u need very skinny seat between ur theighs and balls that flair out to a fatter section for ur butt. good luck!!!