I recently had a birthday and I received many "happy birthdays" in the form of cards and verbal well wishes. I had a great birthday weekend celebrating with my family and extended family. In fact, I still have a few cupcakes left and yes, I'm eating a cupcake right now while writing this column.

At the end of my birthday weekend, I went for a three-mile walk/jog and it felt great. Later that evening though, I started to get sciatic pain symptoms. Some of you just cringed while reading that because you've had those pains. With the help of my chiropractor, ice, stretching, heat, stretching, leg traction in deep water and, of course rest, I am beginning to heal.

During the healing process and while dealing with the pain, I questioned what caused the pain. I did nothing out of the ordinary, just a normal routine. Then the thought of aging came to mind. As I tell many people, growing old is not for sissies. We have to be tough because as we age, we do go through physiological changes.

I was reading about those physiological changes in the American College of Sports Medicine's Position Stand on Exercise and Physical Activity for Older Adults (2009). Here are some of the typical changes that we will all go through as we age:

Muscle strength and power will decline after age 40 and accelerate after age 65-70. Lower body strength declines faster than upper body strength.

Muscle endurance declines.

Reaction time increases. It takes us longer to react.

Flexibility decreases especially in the hip, spine and ankle.

Walking speeds are slower and stride length is shorter.

Blood pressure at rest increases.

Our height declines approximately 1 cm per decade during our 40s and 50s and decline speeds up after age 60.

The average individual will lose approximately 40% of their muscle mass between the ages of 20 and 70.

These are just the biological facts of aging. The good news is that it's never too late to start and exercise program. Regular exercise can improve our health even after years of sedentary and unhealthy behaviors. I've seen many people over the years change their lifestyles and improve their health. It can be done if you choose to do it.

Here's to you choosing to live well.

About the author: Jonathan Souder is the fitness director at Manor House, an ACTS Retirement-Life Community in Seaford. Email your thoughts to jsouder@actslife.org.

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