The characteristics of a healthy person include a high level of high-density lipoprotein cholesterol, a low resting heart rate, balanced muscular strength, a high level of cardiovascular fitness and being happy in work and home life. Together, these factors lower the risk of heart attack, cancer, injury, mental illness and other diseases that are more likely to manifest themselves in less healthy individuals.
Doctors consider a reading above 90 milligrams per deciliter of HDL cholesterol to mean an individual has little chance of suffering from heart disease. HDL cholesterol benefits the body by keeping the heart's arteries clear of the blockages that lead to heart disease and heart attacks. HDL cholesterol can be increased with a program of moderate aerobic exercise performed for 20 minutes a day, four times per week.
A resting heart rate of under 60 beats per minute is considered a sign of longevity. The heart beats a certain number of times before shutting down, so the lower the resting heart rate, the longer an individual can potentially live. Resting heart rate should be measured first thing in the morning before getting out of bed.
Opposing muscles should have a balanced strength. For example, the biceps and triceps should have a 1:1 strength ratio. The quadriceps and hamstrings should have a 3:2 strength ratio.
Happiness at work and home also contribute to a longer lifespan. Those who suffer from unhealthy forms of stress or depression tend to develop more health issues than the general population.