(January 26, 2014 at 10:01 am)wolf39us Wrote: I'm starting to think I'll need to just put aside some time and just say "I'm going cycling for a bit, you wanna come or not?"
Can't really weigh in on advice for a SO that doesn't share your exercising preferences but I'm not entirely averse to saying that you're approach above isn't necessarily a bad approach.
It is unfortunate that she doesn't share your love of cycling but if you want to increase your time exercising it seems like your option right now is to forge ahead on your own while continuing to extend the offer for her to come along while making an attempt to find an activity that you both enjoy and make it a regular thing.
Unless your girlfriend is also on a mission to lose weight and/or get more fit, a solo approach might be a good thing right now since you would have the option to work to your maximum ability without having to worry about whether you're leaving her in the dust or not, while in the meantime talking about a way in which you two can be active together. Another approach you might take is talking to her about joining an exercise class together that you can tailor to your ability levels and goals. This might be a good way to diversify your own workouts and fit in some cross-training while spending time with your girlfriend and being active.
If she likes to stay home and you have a game console of some kind, are there workout or exercise games you can play together like WII fit games or something with that Xbox connect thing that tracks your movements? (I'm not a gamer so I apologize if I got that stuff wrong...

Is it an option for you to bike to work? If you enjoy cycling but don't want to do it on your own in your off-time and take away time with your girlfriend, is there a way to fit in cycling to your daily routine and bike-commute?
Most of all, I'd suggest simply having a talk with your girlfriend about your fitness goals and your desire to spend time with her and seeing how she can contribute or participate in your exercising time.
Teenaged X-Files obsession + Bermuda Triangle episode + Self-led school research project = Atheist.