The benefits of exercise throughout life are often touted. But is it safe for seniors older than 65 years to exercise? Absolutely. According to the American Academy of Family Physicians almost all older people can benefit from additional physical activity. Regular exercise protects from chronic disease, improves mood and lowers chances of injury.

With age, the body does take a little longer to repair itself, but moderate physical activity is good for people of all ages and of all ability levels.

Many medical conditions are improved with exercise, including Alzheimer's and dementia, heart disease, diabetes, colon cancer, high blood pressure and obesity.

Regular exercise improves:

• Immune function
• Cardio-respiratory and cardiovascular function
• Bone density/Osteoporosis
• Gastrointestinal function
• Neuro-cognitive function
• Chronia conditions
• Cancer
• Manage stress
• Improve mood

Regular physical activity is also associated with decreased mortality and age-related morbidity in older adults. In addition, a study by the Journal of the American Geriatrics Society examined exercise in the elderly and found that exercise training led to improvement in functional reach, balance and fear of falling.

Often, frail elderly people are unable to tolerate aerobic exercise routines on a regular basis due to lack of endurance. But while age-related changes in the cardiovascular system have significant effects on cardiac performance, it has been estimated that 50% of endurance loss can be related to decreased muscle mass.

The ideal exercise prescription for the elderly consists of three components: aerobic exercise, strength training, and balance and flexibility.

Workout for the brain, not the body

Over the last two decades, researchers have learned that exercise acts on multiple levels in the brain. The brain's wiring depends on the integrity of the brain cells or neurons, as well as the connections between the neurons, or the synapses.

As we age, the synapses are lost or break down. Researcher have shown that in older rodents, exercise increases the number of synapses and also stimulates the brain to develop more neurons in the hippocampus – a critical region in learning and memory formation and a target of massive decline in Alzheimer's disease.

Still, for those newly created brain cells, or neurons, to work — to help us learn and remember new things — they need to be plugged into the existing neural network, said Romain Meeusen, chair of the department of human physiology at the University of Brussels.

Exercise helps integrate the new neurons into the brain's circuitry to help improve learning, Meeusen said.

In general, exercise increases the release of neurotransmitters, or brain chemicals that relay signals between nerve cells, called neurons, Meeusen said. "This could be one of the mechanisms of the anti-depressive effect of exercise," he said. "It also helps to 'train' cognition and attention at all ages."

Research also suggests that exercise improves blood flow to the brain and, as a result, enhances cognitive abilities. The blood carries oxygen and feeds neural tissues, so you're getting the benefits that come with that.