This astronaut relies on two exercises to build muscle to survive in space | Men’s Health

Former Navy Seal and Harvard med school grad Jonny Kim is on a mission for his potential first travel to space. Healthy adults in space can lose up to 20 percent of their muscle mass in five to 11 days so he needs to ensure to have adequate physical and mental training before his takeoff. His go-to exercise to build muscle strength in space is a back squats and farmer’s walks.