In fact, regular exercise, even started late in life, can help slow down the aging process altogether, so you'll be less likely to suffer from chronic disease or disability, and more likely to be fit and trim, agile, mobile and happy, even as you get older. Furthermore, partaking in light or moderate physical activity has even been found to prolong lifespan.

Here are some ways that exercise can enhance brainpower and mood:

• It reverses the detrimental effects of stress. exercise boosts levels of soothing brain chemicals like serotonin and dopamine.

• It lifts depression. Sustained, sweat-inducing activity can reduce symptoms of depression about as effectively as antidepressants.

• It improves learning. exercise increases the level of brain chemicals called growth factors that help make new brain cells.

• It builds self-esteem and improves body image. Even simply seeing fitness improvements, like running a faster mile or lifting more weight, can improve self-esteem and body image.

Why exercise Is Good for the Brain

As the body ages, the stem cells in the brain tend to become less active and produce fewer new cells, which means that the mind gets slower and "older."

The latest research is showing that by exercising even moderate amounts can trigger processes in the brain that activate the division of stem cells and promote neurogenesis (the production of new brain cells).

One new study has revealed an insight into why exercise is so good for the brain. In summary, it appears that exercise lowers the activity of bone-morphogenetic protein or BMP, which slows the production of new brain cells.

At the same time, exercise increases Noggin, a brain protein that acts against BMP. According to the researchers:

"The more Noggin in your brain, the less BMP activity exists and the more stem cell divisions and neurogenesis [production of new brain cells] you experience."

Even Light or Moderate Physical Activity Reduces the Risk of Early Death

Yet another reason to exercise- researchers have found that even light or moderate intensity physical activity, such as walking or cycling, can substantially reduce the risk of early death.

The study combined the results from the largest studies around the world on the health impact of light and moderate intensity physical activity. It showed that the largest health benefits from light or moderate activity (such as walking and cycling) were in people who do hardly any physical activity at all. Although more activity is better - the benefits of even a small amount of physical activity were very large in the least physically active.

The good news from this study is that you don't have to do huge amounts of exercise to benefit from physical activity. Just achieving the recommended levels of physical activity (equivalent to 30 minutes daily of moderate intensity activity on 5 days a week) reduces the risk of death by 19%, while 7 hours per week of moderate activity (compared with no activity) reduces the risk of death by 24%.

The lead researcher said:

"This research confirms that is not just exercising hard that is good for you but even moderate everyday activities, like walking and cycling, can have major health benefits. Just walking to the shops or walking the children to school can lengthen your life - as well as bringing other benefits for well-being and the environment."

References:

• Mira H, Andreu Z, Suh H, et al. Signaling through BMPR-IA Regulates Quiescence and Long-Term Activity of Neural Stem Cells in the Adult Hippocampus. Cell Stem Cell, Volume 7, Issue 1, 78-89, 2 July 2010.

• Gobeske KT, Das S, Bonaguidi MA, et al. BMP signaling mediates effects of exercise on hippocampal neurogenesis and cognition in mice. PLoS One. 2009 Oct 20;4(10):e7506.

• Woodcock J, Franco OH, Orsini N, Roberts I. Non-vigorous physical activity and all-cause mortality: systematic review and meta-analysis of cohort studies. International Journal of Epidemiology, 2010.