It's important to figure out why you're tired. Are you:
- Over-exercising or not exercising enough
- Coming down with an illness
- Consuming alcoholic beverages (dehydration increases likelihood of pulling a muscle)
- Low on essential vitamins and minerals
- Logging extra hours at work
- Up more than one night with a kiddo
- Bored or feeling lazy
As long as you're sure there's no major issue that will cause you physical harm, give yourself 10 minutes of cardiovascular exercise and see how you feel. At the end of 10 minutes and you still feel overly-tired, stop and move on with your day.
Dehydration - drink approximately 64 ounces of water before exercising.
Fatigue - 10 minutes of interval exercises and get a good night of sleep.
Diet - schedule a visit with your general M.D.
Bored - mix up your routine by hunting down a new exercise, sign up with a partner or team, or hire a personal trainer.