Try a Schwinn AirDyne. They exercise both arms and legs and the
effort required to push them hard is considerable. You won't be reading
a book or watching TV while using one of them, just trying to survive
the workout. But, the rewards of greater strength and endurance will be
worth it. We used to have one-minute competitions at my fitness club
with them. Whoever could take one to the highest RPM and hold it for 60
seconds won. Most people had to recover for awhile afterwards, before
they could walk. The use of all limbs will expand your circulatory and
respiratory capacities and increase your red blood cell count.

The Schwinn AirDynes are built like tanks and rarely break down.
They are moderately priced. The fact that you rarely find used ones for
sale attests to how much their owners appreciate them.

Steve McDonald