Korea is a seemingly very health conscious society. Many products are sold as all natural. Most of the food is produced with less salt than Americans are used to. Some of the their ideas of health seem a little screwy to me.
In addition to watching their diets, many Koreans regularly exercise by walking trails, hiking, or riding bikes. Strategically located along many walking trails are outdoor exercise equipment. I have only seen a couple of indoor gyms. Most of the equipment seems pretty ridiculous to me. You can twist or turn on the machines but they don't appear to actually work any muscle group. There are some bench press type machines but they don't have any weight on them.
Koreans don't like muscular body types. They like long lean muscled frames on men and very very slight frames on women. Either way they don't workout the way Americans do. Here is one of their exercise parks along the trail in the Yongsan Family Park.