I have a daughter and not a lot of time to myself. I figured I could hop on my Gazelle while she naps, or walk to the post office with her to get the mail and maybe get a total of 30 minutes in a day with a couple of excercises. But someone told me that you have to work out for at least 30 minutes or it was a waste of time. Is it true?

Not true. Accumulating exercise in 10 minute chunks for a total of 30 minutes is just as effective as doing all 30 at once.

I am an adamant proponent of the literal translation of EAT LESS, MOVE MORE. If ten minutes is more .... it's good.

Also a mother with a young daughter. I am exercising on a recumbrant bike for 30 minutes a day, but I do like 7 minutes chunks, take a break, get some water and go back. Or if there's a tv show I really want to watch, I'll bike during the commercials. It's easy to add up to 30 minutes like this, and it doesn't have to be all at the same time.
From what my doctor has said, any exercise is better than none.

It is NOT a waste of time.

I began exercising by taking two short 10 minute walks a day. That was 20 minutes. 20 minutes more than I had ever really exercised in my entire life. I have since worked up to about 45 minutes on a treadmill PLUS those two 10 minute walks a day. Without that stepping stone, I NEVER would have even started.

I agree, you would not be wasting your time.

I started out with 10- and 15-minute sessions of exercise because that was all I could do, and sometimes all I had time for. I still only go that long if I just don't have the time or energy. And I'm losing weight and feeling better.

I've learned the hard way that an all-or-nothing attitude gets you nowhere. Do whatever you can; it will do you good.

Any amount of exercise at all does good.

I think the 30 minute stat you are thinking of may be something I read somewhere that said that after 30 minutes of cardio is where your body quits burning off sugars and moves to burning fat...but the sugar will turn to fat if you don't burn it off anyway, so its far from pointless to do less than 30 minutes. Whatever amount you can fit in your life is better than nothing for sure! And there are ways to make even short time frames of exercise effective. I had a friend who would do 5 minutes of vigorous jump roping 3 times a day to lose weight, and it worked really well for her, she swears it did a lot more for her than some other more time consuming exercises.