First of all, people who like fitness don't grow very short and fat, and they have a good figure, so people look sunny and healthy. I have met many bodybuilders, who are generally strict with themselves. They are tall and muscular. For example, my boyfriend is very strong in fitness, so is his friend. He is tall and thin, but he must have muscles and he is big. They walk with their heads held high, which is more imposing and makes people feel comfortable at first sight.
The second is the self-discipline of people who like fitness. They have certain requirements for themselves, whether in life or on themselves, they can have their own goals. What time to get up every day, what time to go to bed, what food to eat is better, and life is extremely regular. Therefore, their sunshine health is not only the shaping of exercise, but also the arrangement of self-life time and regular work and rest. All these make them look sunny.
The third is that people who like sports are generally more casual, giving people a relaxed and happy feeling. And it may be because of fitness exercise that their faces look more cheerful, because they often face the things and people they meet with a happy mood.
A person will have a lot less troubles because of fitness and sports. Those trivial things in life are not important in the eyes of fitness people. So people who exercise are more sunny and healthier.