Tandem standing on a balance mat with alternate arm lifts (Balance, tandem stance, lifting arm overhead, on balance mat)

Stand up straight on a balance mat and place one foot in front of the other.
The toes of your back foot should just touch the heel of your front foot, or as close as possible.
Holding this position, lift one arm up into the air, lower it and then raise the other.
Keep your posture and gaze upright throughout the exercise.