Serious viral pneumonia is more likely to happen in those with a weakened immune system, such as: Babies who are born too early. Children with heart and lung problems. People who have HIV/AIDS. People receiving chemotherapy for cancer, or other medicines that weaken the immune system.
Lower back pain: How exercise helps. When you're in pain you may feel like resting, but staying active is good for your back. Exercises for lower back pain can strengthen back, stomach and leg muscles. They help support your spine, relieving back pain. Ideally, choose activities that involve endurance,strength and flexibility such as walking, swimming or cycling.
1 Swimming is a resistance exercise, similar to weight-lifting. But, unlike weight-lifting, swimming places almost no stress on your joints and bones. So not only does swimming work your muscles but it doesn't have some of the negative impacts that lifting weights has.  There are many muscles that swimming can strengthen.