A good workout should never feel easy—the whole point of exercise is to challenge yourself enough so your body has to adapt to get stronger, faster, fitter. But no matter how tough any workout is, there's always a subjective element to it, depending on your mood and mindset at the time, exercise can feel harder or easier than it should. This winter, it's not just the colder, darker days that make it hard to push yourself through a workout. After nearly a year of living through the COVID-19 pandemic, most people are dealing with serious mental fatigue—something that negatively affects performance by making exercise feel harder, according to a review of 11 studies published in the journal