About concentration, motivation and dropping dead.

I am a beginner guitarist / keyboarder, and I am very motivated but I loose my concentration very fast. My maximum rehersing is one hour and after that I 'm starting to loose concentration. Even afer a break I cant get my mind back on my intrument. I hate that becouse I hear people saying that they play six hours a day practice. I want to play my instrument till I drop dead (but I cant).
Does anyone have a suggestion?

This may sound a little harsh, but the only thing that gets you playing is a love for the instrument. I'm not saying that you don't love it, but if you don't love it enough to play six hours a day then nothing is going to help that. Personally i don't feel you should have to force yourself to practice. However, I'll also add that six hours a day is a ton of guitar, and many great players never played that much a day. I can admit that I don't play that much, nor would I want to. I have other interests in my life besides guitar, although guitar is definatly the biggest. One needs inspiration as well as just practice. If you are practicing the right way for an hour a day, you will improve, simple as that. Depending on the person, that level of improvement will vary.

And while I'm sure that there are some people who play six hours a day straight.... well... I find it hard to believe that a lot of people do. Maybe they factor in the time they spend on breaks and having a snack and reading guitar magazines and stuff like that...

Bottom line: have fun with the instrument.

to me it seems that someone can practice too much, if it gets to the point where it's no fun, then you're going too far. Of course I also believe in working for things... so I guess it's a balancing act. As for me, I find that if I'm realy into what I'm playing hours can go by and I won't notice. Somedays I'm only good for 15 minutes. It all depends.

You've all made good points and I would like to add my own two cents. When I started to play I had my mind set on playing blistering fast riffs from Metallica and rythmic chuggs from Rammstein. I got my first guitar which was an acustic and I was not happy with it, sure I could play some slow medley and chords on it but it wasn't my style. My skills did not progress much because I didn't really enjoy playing, so I convinced my dad that I wanted an electric. He then bought me one and I bought a distortion pedal and started playing until it hurt so bad I could'nt, THEN I grew a "love" for the instrument. So if you really want to play a certan style, buy some equipment and play what YOU WANT TO PLAY. Simple as that.