Pretty much any activity that gets your blood pumping is cardiovascular. When your heart rate rises, muscle cells break down sugar and fat for fuel, burning calories. Clearly there are a ton of ways to do this, but exercise physiologists lump cardio into three buckets -- long, slow distance (LSD), medium hard (tempo) and high-intensity interval training (HIIT).
I've had earbuds that malfunction, sports bras that sag weirdly, and hair ties that pop. I shared my chagrin on the subject with Amy at Second Shift Athlete, who's a whiz with finding ways to exercise, even when faced with a fail. And look at this! Some excellent ideas for dealing with workout clothing malfunctions on the fly.
Since moving to a new town, I've been on a mission. I'm in the market for a new gym. Yes, my building has one (that's one perk of living in an apartment). But sometimes it's not enough (since I work from home, I need an excuse to actually leave the building otherwise I fear I'd never breathe any fresh air or see the outside world.