I always fail doing a workout more than 3 weeks
I am over weight and every time I build up courage to workout I start strong for the first week then day by day I reduce it till I dont fo it at all. I cant control my self I've done everything hiking, mountain climbing, running, biking, swimming,... You name it! When I become good at it then nothing! Any recommendations about how to stay motivated?
Why not go for a new challenge every time you completed the previous one? Climbed 4000 m? Go for Mt. Everest! Climbed it? Run a Marathon. Done with that? Become an NBA star or embarrass young Arnold!
Find that motivation in yourself. Know that you're doing it for your health. Write down your goals and reasons why you workout. Challenge yourself not to give up after 3 weeks. Make a plan and be consistent :)