Stand on the xertube with your legs slightly bent and your back straight.
Being sure to keep your wrist straight throughout the entire movement, use your bicep muscles
to curl the handles up in a semicircular arc from your legs up to a position under your chin.
Contract your biceps at the the top and hold there for one second. Slowly reverse the movement
and repeat. Note keep your upper arms pinned to your side and keep them that way throughout the
Don't let your torso lean backwards or forwards during the movement. Keep your back straight
throughout the entire exercise. If you are having problems keeping your back straight, try
pressing your back against a wall or lessening the weight.