Java infinite loop performance

Question

I have a Thread that only has to work when a certain circumstance comes in. Otherwise it just iterates over an empty infinite loop:

public void run() {
    while(true) {
        if(ball != null) {
             // do some Calculations
        }
    }
}

Does it affect the performance when the loop actually does nothing but it has to check if it has to do the calculation every iteration? Only creating a this Thread when needed is not an option for me, because my class which implements Runnable is a visual object which has be shown all the time.

edit: so is the following a good solution? Or is it better to use a different method (concerning performance)?

private final Object standBy = new Object();

public void run() {
    while(true) {
        synchronized (standBy) {
            while(ball != null)  // should I use while or if here?
                try{ standBy.wait() }
                catch (InterruptedException ie) {}
        }
        if(ball != null) {
             // do some Calculations
        }
}

public void handleCollision(Ball b) {
    // some more code..
    ball = b;
    synchronized (standBy) {
        standBy.notify();
    }
}

Answer 1

I found the following interesting thing. In task manager, running that infinite loop like that, would consume 17% of my CPU. Now, if I added a simple

Thread.sleep(1)

inside the loop, which is only one milisecond, the CPU use dropped to almost zero as if I was not using the program, and the response time of the program was still pretty good on average (in my case it needed to reply things fast)