Well-being involves a sense of vigour, soundness and bodily integrity (health). It also consists of feelings such as contentment, enjoyment, and happiness. Our well-being is enhanced by lifestyle choices about what foods to eat and how much exercise to have at different stages of our lives (childhood, adolescence and during mature adulthood and old age). Well-being is also enhanced by keeping our lives stress-free, by not smoking, and by avoiding harmful drugs. Science has given us information that helps us to make good decisions in these and other areas. It has also helped those of us who are interested in fitness and sports to train more effectively and safely and to perform better in our chosen activity or sport.