There's my problem, during about 10 to 15 minutes both my legs work nicely...  

but them, after a section of double bass... the problem starts, I try to push it to the maximum, but my legs and feet simply does not work until the next day...  

What kind of exercices can I do to help  

ps.: I play heel up most of the time and when doing double bass.

If anyone can help thanks...

Ok, since I'm such a nice guy (new cafe motto here) here's what I do about 3-4 times a week.

1.  Stand on tip toes and ease back into a wall...slow
       I do this till I'm sick of it...about 5-10x

2.  Lift toes in front of tv while keeping heels planted
       I do this till my shin muscles start hurting

3.  Lift heels while keeping toes planted
       I do this while alternating 16ths

4.  Rock back an forth between heels and toes making
     "quad" sound in 16th, 32nds or artificially grouped
     quads within' 1/4 note triplets

5.  Keep feet flat on pedals
     a.)  Turn click on 60
     b.)   Play 1/4's 1/8's  and garden variety triplets
     c.)   Do it with Left Foot

6.  Practice rudiments with your footsies

7.  Check out www.drumcanman.com
     He's fast
    
    

Guys, one thing that has helped me is a stairmaster. I get on a stairmaster atleast 3-4 times a week and I work it 16 minutes with an inverted program. (simulated up and down hills). This thing is great. It will build your endurance too. I play doulbles with my heals down because my feet are faster that way. It's very simlar to playing 6's or straight 32nd notes with your hands. You can only do it properly if you use your wrists. Same with your ankles. It will work the heck out of your thighs and calves but it feels good after a while.

I was just gonna ask if you guys excersise.  Lifting weights and running up hills is helping me a lot.

Mateus-  I would say you are describing a problem that has much to do with the body's natural circulation of lactic acid.   You can work on building your resistance to the problems you've explained (I've had them too).    Essentially, this is a natural reaction and, like any athlete,  you need only to train your legs consistently over time to overcome the problem.    Track your progress and I'm sure you'll find great results over the coming weeks/months.

Here's a bit of info I lifted from http://www.brianmac.demon.co.uk/lactic.htm


....When muscles contract vigorously for long periods the circulatory system begins to lose ground in delivery of oxygen. In these conditions most of the pyruvic acid produced in the breakdown of glucose is converted to lactic acid (LA). As the lactate is produced in the muscles it leaks out into the blood and is carried around the body. If this condition continues the functioning of the body will become impaired and the muscles will fatigue very quickly.

Improving your Lactate Threshold:
The aim is to saturate the muscles in lactic acid which will educate the body's buffering mechanism (alkaline) to deal with it more effectively. The accumulation of lactate in working skeletal muscles is associated with fatigue of this system after 50 to 60 seconds of maximal effort. Sessions should comprise of one to five reps (depends on the athlete's ability) with near to full recovery.

Training continuously at about 85-90% of your maximum heart rate for 20-25 minutes will improve your LT.