According to the Mayo Clinic, exercising helps people control their weight, so not exercising makes it more likely for people to gain weight. Another effect of not exercising is the likelihood that a person acquires health problems, such as heart disease, diabetes, high cholesterol, stroke and even depression.
The Mayo Clinic goes on to say that regular exercise also improves energy levels. This is because physical activity delivers oxygen and important nutrients to muscles. It also increases cardiovascular efficiency. When the heart and lungs work better, people have more energy for normal, everyday activities, exercise and even their sex lives. Therefore, those who do not exercise regularly consequently have less energy.
The Centers for Disease Control mentions that physical activity also helps people have stronger bones and muscles. Therefore, not exercising increases the odds that someone gets arthritis and does not slow the loss of bone density that comes with getting older. Because regularly participating in muscle-strengthening activities builds strength, not doing these exercises has the potential to make a person's muscles weaker. Another benefit of exercise the CDC talks about is reducing the chances of having depression. It is suggested that regular exercise makes people sleep better as well.