For this exercise, you will need: one Fordson Major (1963 model or thereabouts), a grass-cutting attachment and a field of long grass sloping steeply behind you.
Press the little wossisface on the side of the engine and climb onto the machine. Make sure the gearbox is in neutral and the attachment is disengaged. Push the thingummyjig and press the button to start the engine. Then sit for a moment, inhaling the diesel-infused air, taking the time to appreciate the beautiful scenery, the peace of which you have just shattered. (This is a good moment to put on your ear defenders.)
Yoga it must be
Engage the grass cutter, put the engine in reverse and release the clutch, then pull the gizmo to lift the attachment off the ground for the journey uphill. Turn around, placing one hand on the rollbar, and guide the tractor up the hill in an unnecessarily straight line. At the top, reduce the engine speed, drop the attachment, stand on the brake and engage first gear, bearing in mind that leaving it in neutral could send you hurtling to your death. Release the clutch and trundle gently down the hill, relieved that you are in gear, occasionally turning around to watch the long grass spewing out of the side of the attachment. At the bottom of the slope, slow the engine, brake, engage reverse and turn to the other side, ensuring an even development of the back, neck and knees. Repeat for one hour, or until the engine stalls and will not re-start.
May help weight loss as part of an intensive outdoor lifestyle.