We need both sleep and physical activity in order to remain healthy and feel well. When work and life seem to be never-ending and take up your whole day, should you choose to get up early or stay up late for a workout? Or get a full eight hours of sleep? A major case for sleep is that it is a fundamental need and helps restore more than just your energy. Exercise on the other can make you feel better and even helps you sleep. Overall however, it is usually best to choose sleep, especially if you feel like you need it. Also, your workout will be more efficient if you are better rested.
Source: https://www.menshealth.com/health/a30681775/low-energy-when-to-choose-sleep-or-working-out/
