Stan Wawrinka, 40, is approaching his last year of professional tennis. Graham Denholm / Getty Images Stan Wawrinka, the three-time Grand Slam champion, will retire from tennis next year — making the ...

Nick Blackmer is a librarian, fact-checker, and researcher with more than 20 years of experience in consumer-facing health and wellness content. Doing cardio daily can boost endurance, heart health, ...

Beth Skwarecki is Lifehacker’s Senior Health Editor and has been writing about health, fitness, and science here since 2015. Beth was the recipient of the 2017 Carnegie Science Award in science ...

Mercey Livingston is a health and wellness writer and certified Integrative Nutrition Health Coach. She's written about fitness and wellness for Well+Good, Women's Health, Business Insider, and ...

Sherri Gordon, CLC is a certified professional life coach, author, and journalist covering health and wellness, social issues, parenting, and mental health. She also has a certificate of completion ...

Which exercise machine burns the most calories? The one you enjoy and will use the most. Here are our all-time favorite cardio machines we have tested at Live Science. When you purchase through links ...