I recently joined a health club.One of the equipment that I love working out on is the cross trainer. It is a system that replicates the running motions without going physically out in the open. No knee jerks, no hot temperatures(advantages of being in an AC gym), no pollution, only various options of physical fitness like hill, cross country, random, power work out and lots more. I will recommend every fitness enthusiast to use this machine. This machine can easily work out around 250 calories in a session of 15 minutes. Constant feedback in terms of heartbeats, blood pressure, speed, duration, level of intensity, graphical output of the future route and a cool down routine included make it a hot favourite.
Though building up a stamina to last for 15 minutes takes some time, the effort is worth the workout.