I do cardio about 5 or 6 days a week, with sessions in between 20 or 40 minutes at a time. It's on the low side, but I think that's what keeps me coming back to exercise: I don't force myself to the upper limits, and I just keep to what I want to do. I feel great about doing 21 minutes of jogging some days, and I feel the same about jogging for about 40.
Maybe you shouldn't try to hold yourself to a certain time? Further, splitting your sessions up into 5+ days might really help you out. I feel more motivated when I'm doing cardio in bursts (Monday - Friday, for example), rather than every other day. Cardio sessions on more days of the week inspires a feeling of routine, which I think helps a lot.
Personally, I use a combination of jogging + TV. Right now I'm studying a second language, and I use TV programs in that language to force me to concentrate on what I'm watching instead of how much time I've spent exercising. A lot of people can get drawn in by regular TV shows, but I find I kind of just drift in attention unless it's something I have to focus on to understand, or if it's something I really love. If you've got an exercise machine, why not try watching your favourite TV show while exercising?
| Pounds lost: 22.0