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"The take home point here is that even 15 minutes a day of walking, without stopping, provides benefit with regards to cardiovascular morbidity and mortality," he says. Morbidity refers to illness or disease, while mortality refers to death. Research has associated 15 minutes of activity with a 22 percent lower risk of death (mortality), and walking with a 43 percent reduced risk in stroke and reduction the risk factors of heart attack (morbidity), regardless of how fast your heart is beating. "Keep in mind, most of the research that has been done on the benefits of walking have been done without monitoring heart rates during physical activity. Remember, the Fitbit and smart watch apps are still actually a relatively new phenomenon," adds Dr. Weinrauch. Long story, short: The morbidity and mortality benefits of walking seem to occur regardless of your heart's beats per minute (BPMs).