Get on the stepmill for this Tabata-style workout. No, not the stair stepper – we're talking about the stair-treadmill that's like a miniature escalator. Don't touch those handrails, grandpa. They're for rest periods and emergencies only.
Set the thing for five minutes and do one minute of easy climbing, then bring it up to a speed you can just barely handle for twenty seconds.
After the 20-second sprint, grab the handrails and step off, straddling the moving stairs for a quick ten-second break.
Repeat that work-rest interval for six to eight cycles.
Make It Harder: Add a Medicine Ball
Grab a heavy medball and hold it while performing the workout. Hold it any way you like: two hands, one hand, up high, or down low. Between sets, you can dismount the machine or stay on, balancing the ball on the drink holder/instrument panel at the top of the device.
This takes a little practice but it's doable and it forces you to repeatedly do something that requires control and coordination while you're tired – an added, real-world bonus to the workout and a good skill to have.