Numerous studies have shown that COPD patients who use supplemental oxygen live longer and have more active lives than individuals not receiving oxygen. Oxygen therapy is based on the premise that all human cells require sufficient levels of oxygen to function properly. Exercise is often easier for individuals receiving supplemental oxygen because more oxygen is getting to the muscles. Receiving oxygen also helps to reverse the long-term effects of oxygen deficiency on the heart. Oxygen therapy has also been known reduce sleep disruption while also improving concentration and memory levels.