. Those who are brand-new to exercise might not be able to run continually for a minute. Others may already have a fitness routine and want to challenge themselves in a new way. Either way, recognize that running is a new and different stress on your body; even if your heart and lungs are in shape—say, from cycling or swimming—your musculoskeletal system needs time to catch up, Sapper says.
And if you are starting from the very beginning? Don’t stress about it. “Everyone was a beginner at one time, whether they started running when they were little or in their 70s,” Sauriol says.