Sit up straight in a chair with a resistance band securely under both feet.
Hold either end of the band in each hand.
If you can, try to sit without using the back support of the chair.
Keeping your posture up straight, punch one arm directly up into the air.
As you bring this arm down, punch the other arm into the air.
Continue this movement at a steady pace, trying to increase the speed if you can without losing your balance and posture.