best folding exercise bike LISS Cardio
http://eduardoulko464.aircus.com/10-great-best-exercise-bike-to-lose-weight-liss-cardio-public-speakers
The best stationary bikes LISS cardio are somewhat less bulky than a treadmill or even a cross trainer, plus it means you'd swerve the travel to and from the gym (time-efficient for those with hectic schedules)