On days when you cant get out of bed because you are too tired or depressed, what methods do you use to help motivate you to get to the gym?

I have been to the gym yesterday before work and today I woke up too late to go there and get back in time for work. When I did wake up I felt too tired and I feel really ashamed that I didnt go. I am intending on going about 4 or 5 days next week but I need some mental motivation to make myself get out of bed when I am feeling too tired.

I tend to just think about how good it feels when I'm there and the buzz it gives me. Also don't beat yourself up too much if you don't end up going. We all have days where we don't fancy doing something so don't worry. Just make sure you go the next day or whenever you can.

the worst part of excercising is finding the motivation to actually start doing something. but once you're at it, you realize how good it is for your body and your mind.
think about how good and energized you'll feel afterwards and about the results you'll start seeing in a couple of weeks, think about how good you'll look in certain clothes,...