Walking and Jogging with Portable Oxygen Therapy If your lungs aren't delivering enough oxygen to your bloodstream, which is common in people with moderate to severe COPD, you won't be able to give enough oxygen to your organs and muscles when exercising. This can be extremely harmful and result with an aggravation... There are two types of portable oxygen systems on the market: flow generators and concentrators. A flow generator produces oxygen at a constant rate. This type of system is used primarily for home therapy where you can control the amount of oxygen administered at any given time. The oxygen flows through tubing into a mask or cannula that you wear over your nose and mouth. To use a flow generator, attach the tubing to a source of air (such as a tank-style compressor) and adjust the flow through the regulator to match your breathing needs. A concentrator produces large amounts of oxygen compared to its size. These devices are used in hospital settings where the patient's oxygen level is monitored by a doctor or nurse. A small electric motor pulls air through a fibreglass shell that contains thousands of plastic beads coated with silver. The beads absorb the carbon dioxide from the air while letting most of the oxygen pass through. The purified air is then forced back into the room through a venturi tube attached to the device. Users report feeling less tired and more awake after using a concentrator.