Rowing machines – These are both fun to use and will give you a great workout at the same time. If you are looking to build your upper body strength, this is a great way. Just 30 minutes on a rowing machine will make you feel the burn. If you love to kayak or canoe, this will be a great way to get in shape before hitting the water. In fact, most professional rowers spend many hours at the gyms in Allentown PA using rowing machines.