Nothing feels better than getting a great workout in, but the next day getting out of bed can feel like the most arduous task you can do. Here's why. When you're working out, it can be difficult to finish your workout, especially if you are putting everything you have into the activity. Most people who frequently workout realize that as you continue to workout, the workouts can become easier for you, but an exceptionally difficult activity can still leave someone feeling exhausted and incredibly sore. But why?

This incredibly informative video by Ted-Ed shows with great animation why your muscles get tired. Many people tend to blame lactic acid for their soreness, but this explains why that blame may be incorrect. See what elements, atoms and processes are to blame for that soreness. Next time you feel sore the next morning after working out, now you will know why. And hopefully you'll still want to work out after.

Catherine Yeulet