Wow, what an unbelievable workout. I've generally found that bike riding (either moving or non moving) is fairly boring, but not today! Since I'm not able to swim just yet or do other cardio-type stuff (tennis, basketball, etc) I used the bike today at the gym. I did the hill workout for 15 minutes, and WOW. It was easy for about 3 minutes and I had the pace going at around 90, and then it jumped in resistance. I fell to around 80, and then it got to full resistance (dots all the way to the top) and stayed there for around 10 minutes. I had sweat literally dripping off of me and falling on the floor and on the bike. Needless to say that I cleaned the bike and the seat off because it must've looked like someone shot a firehose of sweat at it. I can see myself using it as a form of exercise in the future and it's worth it for sure. Props to Serena for inspiration! I'm not a fan of hers but seeing her effort out there let me know that it could have been way worse. I'm hoping that I am not too sore to get out of bed in the morning.