1) Decrease in muscle mass?  If you are less active than you used to be, you’re probably experiencing a loss of muscle mass. This does not happen because you are getting older. It happens due to lack of activity. Remember the expression... "If you don't use it, you lose it!

2) Decease in strength? Less muscle mass will lead you to experience a decrease in your strength. I lost most of my strength in few short months just prior to having open heart surgery. The loss was solely due to a lack of activity.

3) Slowing of metabolic rate? Less muscle, as the majority of middle aged and older people have, leads to a decrease in your need for oxygen and calories. Muscle tissue is active tissue and needs nutrients.

4) Increase in body fat percentage? If we lose muscle tissue, our body fat as a percentage of our body mass increases. In addition, most of us don’t change our eating habits easily so less activity means less energy use. But if we still eat the same way, we're adding more fat or storage cells.

5) Decrease in aerobic capacity? Aerobic capacity is the ability to rapidly breathe amounts of air into the lungs for aeration of the blood. To deliver large volumes of blood by the pumping of the heart. To transport oxygen throughout your body by a strong vascular system. For example, you may find it getting harder going up the same flight of stairs, getting up from a chair or up off the floor!

6) Blood sugar intolerance? As we age, we may gradually lose the ability to efficiently use the sugar in our blood.  As a result, our blood sugar rises and may increase our chance of developing Type 2 Diabetes.

7) Increasing cholesterol? Cholesterol  is not a required substance in our diet because  our body is able to produce what it needs.  Cholesterol is a fatty substance that’s essential in the construction of cell membranes.  Sometimes it can collect and form deposits in tissues.  When this happens in your blood vessels, it is called ‘atherosclerosis'.  This condition contributes to the development of heart disease.  Cholesterol in our diet comes from animal food sources, there is no cholesterol in plant food.  High cholesterol is largely caused by bad dietary habits like eating too much fat and salt.

8) Increased blood pressure? While this may be partially hereditary, contributing factors are obesity, eating too much fat and salt, drinking too much alcohol and too little exercise. Blood pressure is measured in two parts. The first, systolic, is the pressure the blood exerts on the walls of the arteries when the heart contracts. Secondly, diastolic, is between beats when the heart is taking a rest. If the diastolic is raised your arteries never get a rest. They are constantly stressed, and over time the walls may thicken and stiffen.

9) Increased bone density? Aging produces a decline in the mineral content of bones that leaves a weaker, less dense more brittle skeleton.  When this reaches the point where there is a large increase in the risk of fracture, it’s called osteoporosis.  By the time this occurs some people are old, feeble and frail. As the signs of aging become more prevalent, older people are apt to suffer from falls because of poor balance and weak muscles. Then serious injuries may be the result. Because they have poor muscles, poor balance  and  brittle bones, any fall can then be devastating!

10) Decreasing ability to control internal temperature?  Our bodies have an excellent  temperature control system.  If it is too hot, the main cooling mechanism is to sweat. The evaporation of the sweat cools the body. If it is too cold, the body shivers which generates heat. Both help maintain the 37.5 C or 98.6 F required. To do this properly you need the correct amount of water and blood flow. An imbalance here shows up as the gradual loss of effectiveness of this system.  It seems that as we age our sensations of thirst decline, so we don’t drink enough water. The lack of exercise leads to a lower heart rate and a smaller heart stroke volume (we don’t pump enough blood). This means less blood flow to the skin. I have read that it takes a higher internal temperature to make an older person sweat. The combination means your body may not be able to efficiently maintain a healthy, comfortable temperature.